# Mini diesel engine.



## minh-thanh

Hi All !
Yesterday, I watched some mini diesel engine on youtube, they are great.
a fleeting thought, it could be the next project when i finish V4 (my V4 is not done yet)
I have a few questions:
With mini diesel engine , compression ratio so it can run ?
How much should the oil pressure be?
What time should oil be sprayed on the compression stroke ?
Thanks !


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## Peter Twissell

Are you proposing a direct injection diesel?
I expect production of miniature injectors would be a challenge.
Oil pressure is similar to other IC engines, but the journals may need to be larger.
Compression will depend on the heat loss from the charge to the combustion chamber. In small sizes, this can be another challenge. Small 2 stroke diesels use ether or similar in the fuel to help with ignition.
Injection timing is similar to spark timing in a petrol engine.


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## minh-thanh

Thanks Peter Twissell !
Yes,  a direct injection diesel
It looks like :

Regarding the challenges of making small diesel engines such as injectors, ..., I have read the discussion about it on this forum, it is really a challenge. I hope there are more comments,   advice and information


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## petertha

Sure runs nice. Some details of the injector here on his website. I don't quite understand the plunger / ball valve interaction but maybe the pictures will be more meaningful to some of you.
http://findsminimodelhotbulbengines.dk/Aboutmymodelmaking.html

http://findsminimodelhotbulbengines.dk/truedieselengine/truehorizontaldieselmode.html


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## minh-thanh

petertha !
Thanks for the link , He has great diesel engines. I wish, someday, I could do it like he did.


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## petertha

He has a contact email address on his home page, maybe plans are available or he could elaborate on the injector for you.


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## minh-thanh

petertha !
Thanks for the suggestion!
 I will send email him .


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## Stefan-K

You can try to email him, but i know that He won't give out any Kind of technical Information or Plans. He said this several Times in his Videos, which are very hard to understand, because his englisch speaking sounds very "danish ". So you have to watch his Videos a couple Times to understand them once.
But if you do, you will find some usefull information there.


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## minh-thanh

Stefan-K !
Thanks for the information, I will not waste any time waiting .
I have a question: if the air pressure in the cylinder reaches its maximum when the piston is at TDC (eg 1 bar), how much oil pressure must be achieved to be able to spray into the cylinder?
*If you have not made small diesel engines, don't be afraid to give the answer. If you have experience with large diesel engines, can you tell me how much oil pressure should be greater than the cylinder air pressure?*


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## timar

minh-thanh said:


> Stefan-K !
> Thanks for the information, I will not waste any time waiting .
> I have a question: if the air pressure in the cylinder reaches its maximum when the piston is at TDC (eg 1 bar), how much oil pressure must be achieved to be able to spray into the cylinder?
> *If you have not made small diesel engines, don't be afraid to give the answer. If you have experience with large diesel engines, can you tell me how much oil pressure should be greater than the cylinder air pressure?*


6.25 bore caterpillars: cranking compression 350 psi. Fuel injection valve (nozzle) opening pressure spec (bench test) 400 - 750 psi. Hope this helps. These were pre combustion type engines


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## Ironman2

The pintle type injectors fire at 1323psi on a single cylinder Lister engine I have.
A cam actuated pump will give you all the pressure you need.
If you remember math figuring hydraulic piston forces. Think of the pintle as a piston, with a surface area of a few thousands, (the spray hole) so a spring can keep the injector shut against compression. The injector pressure is needed to open the pintle and to vaporize the oil.


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## Peter Twissell

Fuel pressure is more a function of the requirement to deliver sufficient fuel through the injector in the short time available.
This is, of course, nett fuel pressure, so the difference between gauge fuel pressure and cylinder pressure.


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## minh-thanh

timar !


timar said:


> 6.25 bore caterpillars: *cranking compression 350 psi. Fuel injection valve (nozzle) opening pressure spec (bench test) 400 - 750 psi*. Hope this helps. These were pre combustion type engines



That's the information I desperately need, I don't have a big diesel engine to check, I just need to know how much oil pressure is greater than the pressure in the cylinder and then I'll calculate it proportionally on the small engine.

Ironman2 !


Ironman2 said:


> If you remember math figuring hydraulic piston forces. Think of the pintle as a piston, with a surface area of a few thousands, (the spray hole) so a spring can keep the injector shut against compression. The injector pressure is needed to open the pintle and to vaporize the oil.



Thank you for explaining how injectors work
I'm also learning about how injectors work ...


* timar, Ironman2 , Peter Twissell !*

Thank you for taking the time to reply and information!
I think I should try to make the pump and injectors to test ... before I can start with a mini diesel.

*If anyone has any other information, please discuss it
It could be a mistake when you make a small diesel, or whatever *


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## timar

Yanmar makes small diesels, L40 may be one to look at for ideas, or possibly adapt to the engine you are building. I have seen the injector and pump on the internet for under $50


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## minh-thanh

timar said:


> Yanmar makes small diesels, L40 may be one to look at for ideas, or possibly adapt to the engine you are building. I have seen the injector and pump on the internet for under $50


I think it is quite large with a cylinder about 20 mm


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## timar

Thought it might be a point of reference for injector & pump design


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## minh-thanh

timar said:


> Thought it might be a point of reference for injector & pump design


A good idea !
Thanks .


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## timar

Minh Thanh,
Google disa.it 
On the top left you will find “ history of fuel injection”, click on chapter 1. There is a lot of information that you may find helpful


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## minh-thanh

Hi ALL !
After learning and thinking, I decided: the diesel mini engine will be my next project
 It will be a project that sounds hard to succeed and takes a lot of time and there will be many parts that will be in the trash, so if anyone reads and is interested in this project please  wish me : " good luck" 
I will make injectors and pumps and hope it's okay and will post results in this thread !


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## Cogsy

Good luck Minh - I'll be watching with interest.


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## Peter Twissell

The best of luck, and may the workshop pixies bring the parts and materials you need to the fore.


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## timar

Wish you the best, please keep us posted


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## awake

I look forward to seeing the engine develop!


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## modelmotor

Hallo Minh-Thanh,
You already know me from several model engine projects.My forumname is modelmotor we have had several times a short contact with each other.
I have been watching the building and running from your clean built horizontal one cilinder diesel engine.
What a beauty she is and what a nice running engine.It's finish is so beautifull you might be proud at your 
beautifull Crafmanships work.I hope that you will enjoy your model engine work for many years from now on.


Many greetings from modelmotor-Gerard-The Nethelands-Europe.


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## minh-thanh

Hi  modelmotor !
Thank you for your compliment!


modelmotor said:


> I hope that you will enjoy your model engine work for many years from now on.
> Many greetings from modelmotor-Gerard-The Nethelands-Europe.


That is for sure !
There's one thing I don't like (from myself), when I watch the projects of the members of the forum, and I have a plan to do it someday (maybe I'm too greedy   ).
About engines I have done, it is the result of the help of the members and useful information in this forum, I just try to do well what I have learned from all of you !


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## weir-smith

Minh

I have been following your post and noting the various comments which I think you will find useful. I will add to the discussion with my own experiences re building a true model diesel.
Just over 2 years ago, I decided to attempt to build a true diesel e.g. one that runs on diesel and uses solid fuel injection. I did a lot of research on the net and determined that there were only a handful of engines built. There were several very fine models but I suspect that they were using fuel additive to kerosene or similar which means that getting the engine to run is that much easier because of the significantly lower compression required. Some of the mixes used 30% or more of ether which has a low compression ignition point.

Back to my journey. My engine is a horizontal type with a side shaft to operate the valves via cams. The bore is 45mm with a 80mm stroke and there were no problems with that part of the build.
When it came to building the fuel pump and the injector that was a completely different story. I ended up making 11 pumps and they all failed for different reasons. The main one was attaining the required pressure of 1800 plus psi. Up to 1200 was not a big problem however, after that strange things would happen. I spoke to all and sundry about the problem and came to the conclusion that I was not able to get the near zero clearances required in the pump bore and the two valves. I finally relented to purchasing a commercial pump which was quite small with the intent to remove all of the excess material to make it as small as possible. The pump worked fine and easily produced 4000 psi and at that point I couldn't turn the engine over. So that part of the problem was solved.

The next was to check the compression which I did using a temporary head fitted with a non return valve on both inlet and outlet ports and everything else blocked off.  The piston was fitted with four rings and the best I could do was 300 psi approximately. Note, I had also ground the piston to fit using a cylindrical grinder. The piston was quite long and there was room to fit more rings which were 1.5mm wide. So I added three more rings and re did the test and this time, I reached in excess of 500 psi. That was problem two solved and then onto the injector. 

The injector was a problem in itself because of its small size. I read up on all of the different designed types then developing my own and after twelve attempts I gave up. The problems involved clearances and sealing. I made an injection tester and the target was 1800 psi for pop off. At this pressure, the fuel was easily atomised however, all of my injectors dripped and now reside in the bin. In the end, I purchased a miniature pintal injector nozzle being the smallest that I could find at about $10. I then made a housing for it and went to the trouble of surface grinding the face of the compression plug. When I gave it a try, after putting in a stronger spring, the pop off range was from 2200 to 1400 psi. I set it to 1800 approximately.

After a lot of fiddling around, I managed to get the engine to run with a lot of smoke etc and noise. I clearly haven't got the timing right and the fuel control is too coarse.  I believe I am now  reasonably knowledgeable with respect to building these small engines and if I was to start again, I would have a good look at a long series injector nozzle and machine it down to be left with the barrel and needle which can be as long as 20 to 25mm. Then make a suitable housing. Note, the material that the pintals are made from is very hard e.g. better than 4140 but still machinable. The problem with building the pump, is the very small amount of fuel involved and its associated pressure. The fit between the piston and the bore must be absolute and you can't use conventional ball valves unless you have specialised experience or very good luck.

I would also suggest you purchase one of these cheap Chinese fuel pumps ($20) and have a good look as to how it works and use the non return valve from it. The pintal needle valve can be modified with a Dremel friction blade to give the fuel adjustment slot.  Again refer to the commercial pump to see how it is done. 

Building a true diesel is quite a difficult project and you join a special group if you do so. I have now diverted my attention to another project which is a Fairbanks-Morse R80 which is a three cylinder, igniter  ignition engine. See attachment and note, it is entirely from bar stock e.g. no castings.

Bruce W-S
Western Australia


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## minh-thanh

Hi weir-smith !
About of fuel: I do not plan to use diesel, diesel is too concentrated , with a small engine to create the necessary pressure to vaporize diesel oil is a challenge of endurance of metals (injectors, valve . , pump ..) I just need an engine that runs on the principle of a diesel engine.
  I have 2 ideas to make injectors and one idea to process ball valves - I am trying to make
Thank you very much, especially for the cylinder pressure and oil pressure data, as well as the tips for injectors and pumps and all the difficulties you have encountered


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## minh-thanh

Hi All ! 
Update : Ball valve


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## minh-thanh

Hi ALL !
I just tried it ... I don't know if it is an injector


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## petertha

Minh, have you followed this post (journey!) on the other forum? Not sure what all may apply to you but recently he has some interesting progress videos showing the 'squirt'.


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## minh-thanh

Hi  *Petertha !*
I just post on this forum.
I know that forum for a long time, in the past, I tried to register but was not accepted, 2 times
So I don't watch on that forum
And I can't find it if I'm not a member
Maybe that forum is not for me


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## Mechanicboy

Hi Minh-Thanh..

Spring force in the injection nozzle determines the opening pressure and atomization of the fuel. Weak spring force creates poor atomization of the fuel and too high spring force can damage the injection nozzle and the pump system. A correct adjusted spring force in the nozzle should make a snoring sound during atomization of the fuel when pumping the injection pump. "Snoring" in injection valve who are vibrating to make fuel is atomized.

In a small model diesel engine with the injection equipment, there should be paraffin with 2% oil for lubrication of the pump / nozzle so that it is easier to atomize, better than with ordinary diesel oil from a petrol station. The compression ratio should be 20: 1 which Find Hansen used in his engines. To regulate the speed, there are only springs to regulate the centrifugal regulator with a wedge to regulate the pump volume, ie: tight springs give higher speeds and vice versa.

I recommend you take the same measurements as Find Hansen in cylinder diameter 20 mm and stroke 40 mm (long stroke generate more hot in air before ignite the atomized fuel). Injection pump piston is 2 mm in these engines by Fin Hansen. The length of the pump piston must be longer than the diameter to get less leakage and less side forces in the pump piston/pump house. 2 alternatives to make injection pump leak free: Seal the pump with gasket or pump piston lapped and adapted into the pump housing that has lapped bore (difficult to get sealed in gasket free injection pump). Stroke of pump is determined by regulator who are affacted by spring in a determined revolution.


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## minh-thanh

Hi everybody !
I just tested the injector (I don't know if it is a injector  )
It does not open at a pressure of 4 bar, and opens at a pressure of 7.5 bar of compressed air
Sometimes, the nozzles and the needle are not really airtight


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## bigjy

Hi Minh

How far did you get with the injectors, I am also very interested in small injectors


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## minh-thanh

Hi *bigjy !*
The problem is: the needle and nozzles are not completely sealed, i am trying to figure out how to sharpen the needle and make the nozzle


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## Mechanicboy

The solution : Lap the needle and nozzle togheter to keep sealed.


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## minh-thanh

Mechanicboy said:


> The solution : Lap the needle and nozzle togheter to keep sealed.


I did everything, like making valve of engine and ball valve , and include both at the same time ..... but it was too small
I looked at the tip of the needle with a magnifying glass.   trying everything but  the surface was still not good, 
I still don't have a way to finish the surface


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## Peter Twissell

What materials are you using for the needle and nozzle?


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## johnmcc69

Good luck Minh!
 I don't know much about diesels so I'm interested in how you go about it.

 John


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## minh-thanh

*Peter Twissell !*


Peter Twissell said:


> What materials are you using for the needle and nozzle?


Needle : steel and stainless steel
Nozzle : brass
*johnmcc69 !*


johnmcc69 said:


> Good luck Minh!
> I don't know much about diesels so I'm interested in how you go about it.
> 
> John


Thanks !
I also don't know much about diesel   .

HI All !
I made another injector body, The old one looks like I drilled not alignment
Re-sharpen the needle and make a new spray nozzle: the situation is improving
My small compressor cannot adjust high pressure (above 8 bar), maybe I will have to go to my friend to test
The hole of the nozzle I drilled is  large 1 mm, so it does not spray into "oil mist"
I will buy a 0.5mm drill bit and make a new nozzle

As* Mechanicboy* said " "Snoring" in injection valve who are vibrating to make fuel is atomized."
I hear a  "snoring" and feel a vibrate slightly in injector


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## tim9lives

Good luck. Very cool project


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## Peter Twissell

Some steels, generally the lower strength grades like EN8, are very difficult to achieve a good finish with.
EN24 and EN16 can be finished to a mirror like condition by polishing.


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## weir-smith

Minh

I refer to my original comments re injectors and the difficulty  of getting a good seal with the injector nozzel. I would suggest that you spend a few dollars typically $10 Au and purchase an injector nozzel via ebay of the pintle type or see if you can scrounge one from an injector repair shop.  The pintle pin can be used on its own with your injector body. 
The pin has been ground to a level that you will never achieve and I have found them to work very well op to 2000 psi.

Bruce


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## minh-thanh

*tim9lives !*
Thanks !
*Peter Twissell !*



Peter Twissell said:


> are very difficult to achieve a good finish with.


That's the problem I'm trying to solve .

*weir-smith !*


weir-smith said:


> Minh
> 
> I refer to my original comments re injectors and the difficulty  of getting a good seal with the injector nozzel. I would suggest that you spend a few dollars typically $10 Au and purchase an injector nozzel via ebay of the pintle type or see if you can scrounge one from an injector repair shop.  The pintle pin can be used on its own with your injector body.
> The pin has been ground to a level that you will never achieve and I have found them to work very well op to 2000 psi.
> 
> Bruce



Thank you for the advice! It is definitely an option if I cannot make  needles and nozzles airtight
I have several options for making needles and nozzles and can change to a different injection style
Anyway, there's no time limit, so I'll find a way to do it, I hope so


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## minh-thanh

*Hi All !!! 
I think I made an injector 









*


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## ajoeiam

minh-thanh said:


> *Hi All !!!
> I think I made an injector
> 
> 
> *





Please - - - - I'd like to see a pic of the injector spray pattern . . .


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## Mechanicboy

With patient, you did the injector airtight. Next: test to see the fuel is atomized.


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## minh-thanh

*ajoeiam !*


ajoeiam said:


> Please - - - - I'd like to see a pic of the injector spray pattern . . .


I'll look for the needle, but that's faulty I'll take a picture for you, it's the same.


*Mechanicboy !*
Yes, I will try it when I make pump.
When I cleaned and assembled and completed it, I tested injection with fuel by  pneumatic pressure, I felt it was quite good , everything seems right, I hope so..


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## minh-thanh

*ajoeiam !*



ajoeiam said:


> Please - - - - I'd like to see a pic of the injector spray pattern . . .


I don't have a picture, but I have this, it will be clearer than everything....


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## ajoeiam

minh-thanh said:


> *ajoeiam !*
> 
> 
> I don't have a picture, but I have this, it will be clearer than everything....



Thanks - - - - -a pic of the spray pattern will tell how effective the injector is - - - - is why I was asking.


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## ALEX1952

Please do not be tempted to put a finger over or near the spray pattern  fuel will enter your body, worst case it can kill. I am no expert but I did spend 40 yrs in diesel fuel injection manufacture, and this is the first thing you are told.
The snoring noise is the imjector opening and closing, pump produces pressure, injector opens, pressure decays, injector closes. It takes a high speed camera to capture one cycle. One problem you will have is getting it to open and close quick enough, hence the exremmely high pressures (more than stated here) and high spring pressure. iIts one of the reasons why diesel went electronic (common rail etc) where  injection is controlled by actuators. Its also easier to tinker with if its not producing the desired results. Sorry to waffle.


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## Badhippie

Alex 
Did you work for Bosh or Bosh America or was it another manufacturer 

Thanks Tom


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## minh-thanh

*ALEX1952 !*


ALEX1952 said:


> Please do not be tempted to put a finger over or near the spray pattern  fuel will enter your body, worst case it can kill. I am no expert but I did spend 40 yrs in diesel fuel injection manufacture, and this is the first thing you are told.



Thanks for your advice and warning !
*  "Expert " : 
I don't need you or someone must be an expert to give advice or warning ....
Any suggestions, comments,... based on experience or knowledge ... that is good for me.*



ALEX1952 said:


> One problem you will have is getting it to open and close quick enough, hence the exremmely high pressures (more than stated here) and high spring pressure. iIts one of the reasons why diesel went electronic (common rail etc) where  injection is controlled by actuators. Its also easier to tinker with if its not producing the desired results. Sorry to waffle.



"getting it to open and close quick enough" : I am learning about this
although I do know a little bit about electrical circuit, but first: i need to make a diesel engine that it can run (i hope) and then i can think more about injector control by  electric

Thanks !


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## ALEX1952

Lucas diesel systems which became Lucas Varity then Delphi the last two being American.
   In minh-thanhs last post I don't understand the comment in bold, if it is to chastise for making a comment that was made with good intentions then it could have been better. this is a forum for helping each othe,r whether the advice be good bad or indifferent and comments in reply should at least be civil. I'm getting a bit sensitive in my dottage (my attempt at humour}.


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## ozzie46

I think he is saying a person doesn't need to be an expert to offer advice. Anyone is welcome to comment. 
At least that's the way I take it.

Ron


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## minh-thanh

ozzie46 said:


> I think he is saying a person doesn't need to be an expert to offer advice. Anyone is welcome to comment.
> At least that's the way I take it.
> 
> Ron



Exactly what I mean , Thanks !

 Hi*  ALEX1952 !*
I'm sorry, my english is not good .


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## grahamgollar

Further to the comments by Alex1952, when I was at sea on vessels with propulsion engines up to 40,000BHP we regularly overhauled injectors. Once reassembled and connected to a (hand operated) test pump the pressure was applied slowly up to just before the point of injection and held there for 30secs. this was to check whether there was leakage between the pintle and its seat. If there was no evidence of fuel from the spray holes then the pump was fully depressed to check the spray pattern. These tests were carried out using MDO (Marine Diesel Oil) but once in service the injectors were operated on  HFO Heavy Fuel Oil) which had 180 or 380mm2/sec viscosity so if the injectors worked well on MDO they were sure to be ok on this boiled treacle! Fingers were never  put near the nozzle tip during the tests!

Oh - by the way, definition of an expert:  an EX is a has-been and a SPERT is a drip


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## ALEX1952

It was a full time job for one man to set up enough injectors using the hand pump you mentioned with a test oil to satisfy all the test machines about 100 of them each taking from 3 to 8 injectors all to different specs. with regards to the drip which is why a lot of vehicles have high smoke the plintle (we called it a needle) and nozzle were match ground, and to a certain degree provided a seal, the contact area between pintle and nozzle is very small as are the holes down to .2mm if memory serves and as you say probably more than one. You are obviously talking about the good old days when you could recondtion things and not chuck them as is the norm today. As an aside the needles make superb centre punches they just never need regrinding.


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## ALEX1952

Take your point Ron and sorry minh-thanh for misunderstanding.


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## Richard Hed

ALEX1952 said:


> Lucas diesel systems which became Lucas Varity then Delphi the last two being American.
> In minh-thanhs last post I don't understand the comment in bold, if it is to chastise for making a comment that was made with good intentions then it could have been better. this is a forum for helping each othe,r whether the advice be good bad or indifferent and comments in reply should at least be civil. I'm getting a bit sensitive in my dottage (my attempt at humour}.


No, no no no, Minh Tahn was not chastising--please let it go.  He was explainng that YOU do not needs to be an expert in order for him to take your hint and warning.  That is, anybody giving good information on safety is accepted.


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## Steamchick

Interesting to hear these stories of injector work. Thankyou all!
Minh Thanh: Well done on making an injector. Watching your video clip I saw a single spray from the nozzle - looked pretty good to me: the classic cone spray. But I think that a "real" injector will be operating normally at much higher pressures than your plastic pipe can manage. (>30bar? >2000psi?). Steel pipe on "real" high-speed diesel engines is used to withstand the pressure (pulse) developed by the injector pump - which in turn opens the valve in the injector and allows the spray. The pressure in the cylinder is at anything up to 23 bar when the injector operates, so you have to overcome this pressure before the spray can happen.  Check you design calculations to be sure your injector can withstand such pressure. 
But (from my poor memory of 50 years ago) when as an apprentice I was shown the job and tested a box full of used injectors (yeah, made me an "ex-spurt"!), the "spray" was more of a conical cloud of diesel oil. I was using a Lucas CAV Hand-pump tester for diesel injectors. A very simple device comprising a hand pump, pressure gauge, steel pipe-work, reservoir for fuel oil, and mounting to connect a single injector. 
See this for a modern version: Beta Diesel Injector Test and Calibrating Hand Pump - 960PMC





The idea (keeping hands, eyes and clothes away from the spray) being to check with a single pump stroke that the spray was conical against a plate with a cone drawn on it, no drip from the injector, and the injector opening pressure exceeded some value on the gauge. Maybe Alex 1952 can enlarge on details as I am sure from his 40 years experience he knows the kit I used for about 1 hour.... But in that hour I was told that if I put my finger over the injector and pumped, the oil would inject through the skin into my blood stream and kill me. Or at least I would be very ill and probably loose the finger as the oil would kill the flesh...  So Alex is exactly right with his advice.
Take care. Wear Protective goggles, to keep splashes from your eyes, have a fire extinguisher within reach as Oil-mist clouds are highly inflammable, ensure no ignition sources exist, and wear appropriate hand protection as the oil can cause dermatitis (bad skin). There is a similar safety warning on this page, which should teach you anything the contributors above have not already mentioned: Diesel Tractor Injector Testing and Overhaul
Enjoy!
K2


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## Steamchick

Minh Thanh:
In your drawing the spray hole is relatively long - which will encourage a jet of oil, not the shear action at the pressure change that encourages the spray to form... (Please research the dynamics of fluids at jets to understand things that I don't, as I may be completely wrong?).




BUT, the drawings of injectors (from the web) show very short exit holes, where the needle/pintle extends through the hole - which I understand is to assist the formation of shear between the moving oil and stationary air/metal and encourages the spray formation? - So please re-check your design of the nozzle against the accepted theory?




Thanks for generating an interesting topic!
K2


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## ALEX1952

In practice the spray pattern is not allways conical, it is sometimes shaped using different sized holes and angles, more so laterly trying to satisfy emissions, again a reason for going to electronic control, however if you do manage to get a good spray of fuel at the right time and pressure with no drip you will have achieved something that many have not or would not attempt, me included, I had enough problems with all the right gear. I'm ashamed to say that if we did have some high smoke pumps and the destination didn't have tight emission control they would probably go depending upon how busy we were. Injection pipes also get very hot and are noisy, why I don't know.


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## Mechanicboy

Minh Thanh..

There is difference type of the injector: 1. Tap outside the hole as picture showed by Steamchick are used in vortex chamber diesel engine , 2. very small hole who are near unvisible for the eye for car diesel engine or a bit larger for ship engine after the injection needle valve in direct injection diesel engine or 3. conical valve outside the hole in direction diesel engine (older type injection nozzle Burmeister & Wain), Find Hansen used this principle to run his model diesel engine. 

The common rail diesel engine has constant high pressure diesel pump and the injector is controlled by ECU (Electronic computer unit) also same pressure in both ends of injection needle: no injection and the pressure is disappeared from upper part of injection needle valve when the injection valve is lifted up by pressure: injection is in working while the tradidional injector is activated by fuel injection pump (powered by hydraulic principe to lift the injection valve needle).

The injector for hot bulb engine is difference from diesel engine: One way valve and the orifice similar Primus kerosene stove or adjustable spray nozzle to regulate from thin jet to atomized diesel fuel to control the heat of hot bulb to example full load the thin jet goes direct into the cylinder and under idling atomized diesel fuel to keep hot bulb warm.


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## minh-thanh

Hi All !
Thanks for the comments !

About the plastic tube:  I just tested to see if my injector is okay ...
About the nozzle : when I made the injector, I just thought and tried to make it sealed, when the injector is ok ( i hope so ) I shortened the nozzle
About of injection pressure ... I thought I would have to design and build an engine with a cylinder diameter of about 20 mm, and check the pressure in the cylinder, that would give me a few parameters needed.
 About the pump to check the injector, if possible,  I think i will to change the hydraulic jack to a pump.  ( My brother gave me an old hydraulic jack , cheap one ) maybe it will save money


----------



## grahamgollar

Quite right ALEX. I've got a collection of pintles/needles for use as centre pops or centre finders. You're also correct about today's throw away technology BUT if you're half way  across the Pacific in a Force 9 hoolie and injectors malfunction (a polite description) there is still no alternative to the old fashioned approach. A Marine Engineer's tool bench always has a porthole glass and a pot of jeweller's rouge ready to hand.


----------



## SailplaneDriver

grahamgollar said:


> Oh - by the way, definition of an expert:  an EX is a has-been and a SPERT is a drip



When I was working, an expert was anyone wearing a tie from 100 miles or more away.


----------



## Steamchick

Hi again :
I don't know all the calculations (just some), but the intention of compression for diesel engines is to heat the air "instantaneously" in the compression stroke so that when the fuel is injected it hits air above the flash point of the fuel - so "instantly" ignites and burns for the firing stroke. Of course, hot-bulb, glow-plug and other devices enable cold starting, and provide a heat source when running to assist ignition, thus allowing lower compression ratios to be used. I suggest you read some texts on this before deciding a minimum compression ratio that you should exceed when designing your engine. 
See this on pre-combustion chambers: Diesel engine pre-combustion chamber - Yahoo Search Results Video Search Results
Mostly used on indirect engines for smaller diesels, such as cars - as the larger engines - for trucks, ships and power stations can manage without (and are more efficient!). They are effectively a development from the hot bulb - where the early engines used to inject/ignite the fuel spray.
Glow-plugs are initially heated by the electric current, but then remain hot (and glowing) heated by the running engine, thus ensuring reliable ignition of the fuel when injected. But on larger engines, at the highest compression, the ignition is simply from the heated air from the compression stroke. 
I may be wrong, but the I understand the reason for maintaining compression below a certain point is to minimise the Nitrous Oxides in the exhaust, produced when the combustion temperature exceeds 920degrees C or thereabouts. Particularly in modern vehicle engines. Also a boosted (turbocharged or supercharged) engine uses a lower compression ratio, so the final pressure at injection is where it is most desirable for the optimum combustion. - but I doubt you are interested in that for your model! 
At the smallest end, model aircraft diesel engines use ether in the fuel which has a very low flash point so ignites freely with the elevated temperature of the compressed air from the available heat of compression. Glow-plug engines have no need for ether. (Ether Fumes are horrid for people! - You fall asleep and wake with a hangover!).
Mention of diesel fuel pipes getting hot is (as I understand?) simply from the work done by the injection pump - the fuel is effectively the cooling fluid for the pump and carries away most of the heat developed in the pump. But as the fuel flow is small the temperature must be high. Actually, the heat is also developed as the pulsations in pressure in the fuel pipes stress (expand) and relax (contract) the steel tube  and the pump is doing the work to stress (expand) the pipes, and when the injector opens the work absorbed in the stress of the steel pipe is released into the fuel - and some of this work is lost as heat... which adds to the heat from cooling the pump. (Enough of the physics!).
Enjoy your modelling!
K2


----------



## Mechanicboy

minh-thanh said:


> About the pump to check the injector, if possible,  I think i will to change the hydraulic jack to a pump.  ( My brother gave me an old hydraulic jack , cheap one ) maybe it will save money



You can create the test instument with the fuel injection pump cylinder/piston from old diesel pump from diesel car engine + manometer to test the injector.


----------



## Mechanicboy

Steamchick said:


> Glow-plugs are initially heated by the electric current, but then remain hot (and glowing) heated by the running engine, thus ensuring reliable ignition of the fuel when injected. But on larger engines, at the highest compression, the ignition is simply from the heated air from the compression stroke.



In the glow plug engines who are using the methanol as base fuel are glowing under running due catalytic reaction affected by methanol to ignite methanol/air mix.

In the car diesel engine the glow plug are to preheating the air before start up the cold engine, then the engine is running then the glow plug is not glowing. Ignited by heat of compression after the engine is started up.

Compression ratio in the pre camber diesel engine: 20:1-25:1
Compression ratio in the direct injection diesel engine: 14:1-18:1
Compression ratio in the hot bulb engine/semidiesel engine : 6:1- 8:1 With torch lamp in continous use. 12:1-14:1 torch lamp for heat up before start up the engine and torch lamp not in use under running (some had glowplug to start up the engine and running with the hot bulb heated by combustion to example in these norwegian semidiesel engines Rap , Brunvoll and Wichman semidiesel socalled "cold cylinder head" start up with glow plug and run with hot bulb who are inside the cylinder head).

In the Find Hansen model diesel engine who has direct injection the compression ratio is 20:1 due the engine is so small that it need higher compression ratio to heat up the air before the fuel is injected 45 degree before BDC and the engine has 20 mm bore/40 mm stroke. In the large direct injection diesel has the compression ratio between 14:1-18:1 depending on  bore/stroke ratio and the injection timing can be between 10-20 degree before BDC depending on rpm and heat of compression.

Norwegian Brunvoll semidiesel started up with glowplug and running with hot bulb who are inside the cylinder head socalled "cold cylinder head" as here the movie.


----------



## Steamchick

Thanks Jens, very interesting stuff! 
Just a comment - and I may have got it wrong... - from what I was taught at work by the "diesel engineer" about the current design of car diesel engines: Glow plugs take 1 or 2 seconds to cool down, after the electric current is turned off. But they are in the hot combustion zone of the engine so remain hot - up near the combustion temperature - as the flames at around 900degrees C keep them hot. The design of the glow plug involves making them so they don't burn away with being in the combustion chamber, so they have similar requirements to the central electrodes of spark plugs as regards heat flow. 
Also, to avoid carbon build-up on "cold surfaces", I understand the end of the glow-plug remains above 750~800 degrees C ? - I think surfaces below 700degrees C gather carbon on the surface? I'm sure I have seen glow-plugs when removed from engines and the end centimeter or so is clean of carbon? - But maybe I am wrong, as I have very little experience of this - and it was more than 30 years ago....  I am not an expert, just an "ex-spurt".
Interesting to hear about the various designs that you obviously understand well.
K2


----------



## Mechanicboy

Steamchick said:


> Thanks Jens, very interesting stuff!
> Just a comment - and I may have got it wrong... - from what I was taught at work by the "diesel engineer" about the current design of car diesel engines: Glow plugs take 1 or 2 seconds to cool down, after the electric current is turned off. But they are in the hot combustion zone of the engine so remain hot - up near the combustion temperature - as the flames at around 900degrees C keep them hot. The design of the glow plug involves making them so they don't burn away with being in the combustion chamber, so they have similar requirements to the central electrodes of spark plugs as regards heat flow.
> Also, to avoid carbon build-up on "cold surfaces", I understand the end of the glow-plug remains above 750~800 degrees C ? - I think surfaces below 700degrees C gather carbon on the surface? I'm sure I have seen glow-plugs when removed from engines and the end centimeter or so is clean of carbon? - But maybe I am wrong, as I have very little experience of this - and it was more than 30 years ago....  I am not an expert, just an "ex-spurt".
> Interesting to hear about the various designs that you obviously understand well.
> K2



In the glow plug is not glowing  in the whole time after the engine is started up due the glow plug is cooled down via cylinder head, but remain hot enough to avoid carbon build up, normally between 500 and 800 ° C (932 and 1472 ° F). This is important because it determines the efficiency of self-cleaning of the plug and is determined by a number of factors, but first and foremost the actual temperature in the combustion chamber. If in case, the diesel engine can't be a real diesel engine when the fuel mix is ignited by glow plug instead heat of compression same manner as semidiesel engine.  In fact the diesel engine with glow plug can start up without use the glow plug if outside air is not cold.


----------



## minh-thanh

Mechanicboy said:


> You can create the test instument with the fuel injection pump cylinder/piston from old diesel pump from diesel car engine + manometer to test the injector.


 Mechanicboy !
Did you say pump as in the picture ?





Lots of useful information .
Thanks guys !


----------



## Mechanicboy

Thanh, this is feeding pump for diesel pump in the picture you marked with red circle. It's the pump element for diesel engine you need to create own testpump for injector.  And keep pump clean with fuel filter between the fuel container and diesel pump.


----------



## Steamchick

Thanks Jens.
You make sense.
K2


----------



## minh-thanh

Hi ALL !
Too long for an update :
I just finished designing the engine
Bore : 19 mm , stroke : 38 mm


----------



## Mechanicboy

Hi Minh-Thanh..

Diesel pump needs an important part: Centrifugal regulator. With a centrifugal regulator, the engine gets the right amount of diesel injected into the engine at a certain speed. The throttling lever is connected to springs which actuate the centrifugal regulator. Tight springs = the engine runs faster and vice versa. During constant speed, the regulator constantly regulates the amount of diesel whether there is little or a lot of diesel that is regulated. If you load the engine, the regulator increases the amount of diesel more and vice versa.


----------



## minh-thanh

Jens  !
Thanks!
I'll make it simpler, I just need the engine to run if i can


----------



## Mechanicboy

Minh-Thanh..  
If you let the engine regulate the amount of diesel and you adjust the idle with the spring, for example the idle screw on the throttle lever and another screw to the maximum speed on the throttle lever, then it is much easier than regulating on the pump itself without regulator.


----------



## sition

NICE


----------



## minh-thanh

sition !
Thanks !
Hi All !
I will make the oil pump
I have a question: does the piston need an O-ring for sealing ?
If I make piston without O ring,  will it be ok ?


----------



## Willyb

Enjoying your Diesel Engine build.

If you are talking about the piston in the cylinder, you are going to need metal piston rings as I don't really think O rings can stand up to the high compression pressures.  For very long.
In regards to the Plunger and Barrel in conventional injection pumps, they do not use any type of seals. They seal using the diesel fuel in a very small clearance between these two parts. The Plunger is lapped to the Barrel to get this small clearance they require to make the seal.  The fuel also lubricates these parts.

Cheers
Willy


----------



## Steamchick

Working at a car factory, and taking engines from a different manufacturer's factory, we had to guarantee the lubricity of first-fill fuel, in order to not ruin the fuel pumps and injectors when first started. Apparently, "any old fuel" would not do, as if the lubricity was too low, we could ruin the fuel pump in seconds at first starting.
Also, This is why the guarantee on the car is voided if you do not use proprietary fuels... (e.g. if you use a gallon of cooking oil with a coffee mug of white spirit in it!). While the engine will run with rubbish fuel, the wear on the high pressure fuelling components will be thousands of times higher than normal, and the components when worn cannot produce the fine spray pattern for cleanest combustion, so you'll get a smokey engine before it stops. You could have an expensive bill in just a few thousand miles, instead of a few hundred thousand miles.
I made a "ring-less" 1cc marine diesel for model aero-fuel... but the compression disappeared after the first few runs, as the bore and piston "ran-in". They had been lapped to the best fit I could achieve, but I guess the materials were no good for this due to the rapid wear I experienced.
After lapping, I suggest a very thorough clean to eliminate all lapping compound... Maybe my cleaning wasn't good enough?
K2


----------



## minh-thanh

Thanks for the comment !
A update :
The outlet pressure is quite good, but there is little oil coming out at the top
I use toothpaste for sealing the balls and valve seat
A project that I'm not sure will succeed


----------



## minh-thanh

Hi All !
I just tested :
the pressure is quite high, I can't seal the injector
It seems to be pretty good
I had to make new piston  and lap cylinder , they weren't so good


----------



## Alec Ryals

minh-thanh said:


> Hi All !
> I just tested :
> the pressure is quite high, I can't seal the injector
> It seems to be pretty good
> I had to make new piston  and lap cylinder , they weren't so good



If thats you hand  its going to  mess your tentendts up !  looks Great


----------



## Steamchick

Just NEVER put any flesh adjacent to the orifice of the injector. You WILL inject fuel through the skin, and possibly get brain damage or death as a result of the fuel passing around the body. It was the FIRST AND MOST IMPORTANT SAFETY RULE that I was taught when a teenage apprentice. Usually nowadays, the injection is into a plastic tube or bottle (clear) but we used large glass bottles (1 pint milk bottles) which we had to wash out afterwards. That way you can see the spray pattern, and collect the fuel for use later. 
K2


----------



## petertha

That's really neat. So where to go from here? How to translate that amount of 'hand energy' to make the squirt in an engine? Mechanically activated? Solenoid activated? etc.


----------



## minh-thanh

Thanks for the comments !
*petertha !*
Oil pump controlled by cam lobe
You can see the last picture in post 76


----------



## Willyb

How are you planning to control the amount of fuel delivered per injection?
Your injector spray looks good but time will tell how it acts under the pressure of compression?
A very fine mist ignites well from the compression heat and has little smoke. Bigger droplets don't ignite as well and produce allot of smoke.
Keep up the good work.

Cheers
Willy


----------



## Steamchick

Don't quote me on this, but I have an idea Bosch  and CAV mechanical pumps were up to 8 or 900 psi, before the move to common rail and piezo injectors... Now those have gone from 1200 to 1600 plus psi impulsive pressure. You can't measure those injection pressures on a gauge, as they are impulsive, I.E. A shock wave generated when the injector is fired.
Looking at M-t's injection, the pressure is too low, by hand. But a cam at speed is a different matter. 
I remember injector testing with a CAV hand-pump in the 1960s. But I can't   remember the pressures we had for valve opening, and to witness a "good spray cone". But the intrusions were on the label affixed to the device. I think they are still available on e&@y, etc...
K2


----------



## Steamchick

ALEX1952 said:


> In practice the spray pattern is not allways conical, it is sometimes shaped using different sized holes and angles, more so laterly trying to satisfy emissions, again a reason for going to electronic control, however if you do manage to get a good spray of fuel at the right time and pressure with no drip you will have achieved something that many have not or would not attempt, me included, I had enough problems with all the right gear. I'm ashamed to say that if we did have some high smoke pumps and the destination didn't have tight emission control they would probably go depending upon how busy we were. Injection pipes also get very hot and are noisy, why I don't know.


Hi Alex, first, I am NOT a diesel expert, just had a bit of training  50-plus years ago, and a bit of modern train while I was the emissions Engineer at a car plant.
Pipes get hot because of the hot fuel oil within, heated by the pump. The noise is the shock wave from each firing pulse of pressure. I don't know sonic speed in oil at high pressure, but the speed of the shock wave is supersonic in air at atmospheric pressure, so it is effectively a series of Sonic booms - all be it very small ones - that you are hearing. That is why it is so loud. On a molecular level, the shock wave in the oil is a pulse of energy, that travels through various media at the sgonic speed for each  medium. The steel pipework feels the internal pressure wave travelling along and flexes sympathetically (at a molecular level) to transmit the pressure wave from the oil to the air. But this wave is travelling along the pipe  at speeds that are supersonic in air, and the molecules of air excited as the shock wave passes cause a sympathetic shock wave in the air that travels at a super-sonic speed in the air from one end to the other of the pipe.  Hence the sonic booms. But that is only my imaginative explanation (guesswork!), not that of an expert.
Please can an Expert explain this and teach us all?
K2


----------



## minh-thanh

Hi All !
I just redid the new cylinder, it sprays a little better .







Willyb said:


> How are you planning to control the amount of fuel delivered per injection?
> Your injector spray looks good but time will tell how it acts under the pressure of compression?
> A very fine mist ignites well from the compression heat and has little smoke. Bigger droplets don't ignite as well and produce allot of smoke.
> Keep up the good work.
> 
> Cheers
> Willy



I plan to  control the amount of oil entering the engine with the cam lobe height and the oil pressure adjustment bolt .
A project of which I do not know the outcome !


----------



## Mechanicboy

minh-thanh said:


> I plan to  control the amount of oil entering the engine with the cam lobe height and the oil pressure adjustment bolt .
> A project of which I do not know the outcome !



In fact not possible without centrifucal regulator. 
Use centrifugal regulator, it's practical to control correct amount of fuel affected by engine via force of spring to regulate amount  of fuel automatic by engine. To regulate required revolution: regulate the force of spring on the centrifugal regulator with the lever.

See at this movie why we need the centifugal regulator and the spring to regulate revolution and amount of fuel..


----------



## Mechanicboy

Minh-Thanh..

Take a study how the centrifugal regulator works as here, begin at the timeline 12:30 in this movie..


----------



## Willyb

minh-thanh said:


> Hi All !
> I just redid the new cylinder, it sprays a little better .
> View attachment 126716
> 
> 
> 
> 
> I plan to  control the amount of oil entering the engine with the cam lobe height and the oil pressure adjustment bolt .
> A project of which I do not know the outcome !



The problem with both of these methods, is there is no feedback from the engines speed and they are not easily adjustable while the diesel engine is running. The cam lobe height is a fixed distance so your fuel oil delivery will be a fixed amount. The fuel pressure adjustment bolt has similar issues. Diesel engines speed is controlled by the amount of fuel injected into the cylinder. The amount of injected fuel needs to be controlled by the throttle and a governor with the governor having complete control.
As Mechanicboy has stated in post #94 and #95 you require some type of governor (centrifugal is the easiest and works well) to adjust the amount of fuel delivered depending on engine speed.
Find Hansen's diesel engine uses a movable wedge plate that moves in and out of the space between the cam lobe and the injection pump plunger. This plate is directly connected to the output of a centrifugal governor.  When the thinnest part of the wedge is in the space between the cam and plunger, the amount of fuel injected will be small. As the thicker part of the wedge moves in, more fuel is injected because there is less space between the cam and the plunger. It is a simple method and works wonderfully at controlling fuel delivery. I have yet to come up with or see any better way of controlling ones fuel delivery on a model diesel engine. 
Keep up the good work.
Cheers
Willy



I can't think of have


----------



## minh-thanh

Mechanicboy, Willyb !
Thanks !

If I just need the engine to run - I don't need adjust the speed , because I don't know if the pump and the injector are fine , so  do I need that part ?


----------



## Nerd1000

minh-thanh said:


> Mechanicboy, Willyb !
> Thanks !
> 
> If I just need the engine to run - I don't need adjust the speed , because I don't know if the pump and the injector are fine , so  do I need that part ?


I think the danger is what happens if your engine works better (makes more power) than you expected. Without a governor it could accelerate to such high RPM that it throws a rod or suffers some other catastrophic failure.


----------



## minh-thanh

*Nerd !*
Although I'm not sure the engine will run.  
But that's a good reason to think !
Thanks !


----------



## Mechanicboy

Nerd1000 said:


> I think the danger is what happens if your engine works better (makes more power) than you expected. Without a governor it could accelerate to such high RPM that it throws a rod or suffers some other catastrophic failure.



Minh-Thanh.. 

I have experienced the vacuum regulator did not work (regulation takes place by vacuum which affects the piston when there is a high vacuum = less fuel and vice versa) in the Sabb semi-diesel engine. The engine ran so fast like a crazy horse that I had to stop the engine immediately by holding the lever down so the engine could not pump the fuel into the engine.
It is actually dangerous that the connecting rod can break in two and make holes in the crankcase / bottom frame. The reason was lack of vacuum due to leather packaging in the piston was hard and dry.


----------



## Willyb

As Nerd1000 has cautioned in post #98. Diesel engines are totally different from their brother the gasoline engine. Gas engines with a carburetor or injector/throttle body limit and control the amount of fuel/air entering the engine. With diesel engines the intake passage to the cylinders is wide open. All diesel engines while operating at their full horsepower rating have an excess of oxygen in their cylinders after combustion. With the addition of more fuel and you will have a runaway.  There are basically two ways to stop a runaway diesel. Cut off it's air or cut off it’s fuel. When I worked as a diesel mechanic I rebuilt allot of medium to large truck diesel engines. On startup after a rebuild I always made sure to have the manual handy to place over the intake pipe in the event of a runaway. Another method was to discharge a CO2 fire extinguisher into the intake which displaced the oxygen with Carbon dioxide. Some guys kept a hammer handy to break off a fuel line or fitting and try and starve the diesel of fuel. Never like that method as it usually wasn’t fast enough. I remember one guy tried to stop his runaway by putting the truck in gear to stall the engine. Didn’t work. In fact not only did the diesel require rebuilding, but it also required a new clutch. Have witnessed two runaways and in both cases the engines required overhauling, again.

All I’m trying to say here is be very careful. Without any proper fuel control you can end up with an uncontrollable engine and possibly a bomb.

Cheers
Willy


----------



## Mechanicboy

Minh-Thanh,.. easy to remember the rule:

Rule 1

A certain speed has a certain amount of diesel that is injected into the cylinder which is impossible for a designer to make a diesel engine without a regulator whether it is mechanical or electronic as the amount varies constantly under a certain speed range depending on the load of the engine.

Rule 2

The speed can be regulated by means of spring force in the centrifugal regulator or via ECU in the common rail diesel engine which is set on by the operator himself who wants the engine to run a certain specific speed.

Rule 3

Diesel engine always has excess air in the cylinder that is not regulated, only amount of diesel via diesel pump combined with regulator either it's mechanical or electronic.


----------



## mcostello

A friend was in the military and rebuilding a 8" howlizer  engine and had a runaway. The engine blew and put the piston through the block and threw a block wall. He heard of another one running away and to stop it a Guy fell on the intake to stop the air. It pulled His intestines out and He died later, trying to save Others.


----------



## tim9lives

Willy B is absolutely right. I’m surly not an expert but my 20 years of turning wrenches taught me to always think about how I was going to kill the runaway diesel. Whenever I would begin to work on a MB, I’d have some sort of ball or pan which I could jam into the intake if the engine began to run away. I had to do just that on a few occasions. Damned things would start to run away and you’d better have a way to kill the airflow or you’d end up with a blown engine. Scares the hell out of you when they start to scream.


----------



## minh-thanh

After reading the comments, I thought:
The engine is pretty small, it can explode and become a bomb I don't know, but anyway I don't want it damaged when running uncontrollably - if the engine can run
2/ With a little experience: Adjusting the initial amount of oil will make it easier to start the engine
 .....
  So I will design and make a part to adjust the piston stroke of the pump
  Thanks for the comments .
Thanks so much !


----------



## tim9lives

You could easily design a butterfly plate to close off airflow. It would look like a choke plate on a carburetor.


----------



## djswain1

Steamchick said:


> Don't quote me on this, but I have an idea Bosch  and CAV mechanical pumps were up to 8 or 900 psi, before the move to common rail and piezo injectors... Now those have gone from 1200 to 1600 plus psi impulsive pressure. You can't measure those injection pressures on a gauge, as they are impulsive, I.E. A shock wave generated when the injector is fired.
> Looking at M-t's injection, the pressure is too low, by hand. But a cam at speed is a different matter.
> I remember injector testing with a CAV hand-pump in the 1960s. But I can't   remember the pressures we had for valve opening, and to witness a "good spray cone". But the intrusions were on the label affixed to the device. I think they are still available on e&@y, etc...
> K2


Mechanical dieseel engines in production today (and since 1970's) that I work use injection pressure IRO 2100 - 3200 PSI
 Common rail pressures are 10x that... see picture


----------



## reichpaul630

fwiw, here's some tech stuff on the Bosch VE distributor-type injection pump series. it's been a real
workhorse in a lot of truck and car diesel engines. my VW has one of these.

the requirements for a pump design, and ways that the requirements were achieved are described in
some detail.  in particular, the internal governor may be interesting

it's may be worth referring to the designs Find Hansen came up with. there's an example HERE.

i'm quite interested to see what the OP comes up with.

paulr


----------



## Badhippie

Better make sure you install a deadman lever. You may need it at some point 
Thanks 
Tom


----------



## minh-thanh

Hi All ! 
An update :


----------



## ajoeiam

minh-thanh said:


> Hi All !
> An update :



Curious - - - are you making the gears as well?


----------



## minh-thanh

ajoeiam said:


> Curious - - - are you making the gears as well?


Yes i made the gears myself, it's not accurate
You can download the image and zoom in and you will see
Hi All !
More :
Piston will have 3 rings.


----------



## Richard Hed

minh-thanh said:


> Yes i made the gears myself, it's not accurate
> You can download the image and zoom in and you will see
> Hi All !
> More :
> Piston will have 3 rings.


Accurate enough.


----------



## minh-thanh

Richard Hed said:


> Accurate enough.


 Accurate enough with 2 : 1 . ratio


----------



## Mechanicboy

Diameter in the hole for wrist pin looks a little too thin considering the forces from the combustion pressure can be strong enough to break off the wrist pin.


----------



## Willyb

minh-thanh said:


> Hi All !
> An update :



Hi minh-thanh

Nice parts. Keep up the good work.

Cheers
Willy


----------



## Steamchick

Do you calculate your sizes? - e.g. Wrist pin diameter? - Fatigue strength is all important to prevent failures. I'm curious for your calculations on that...
K2


----------



## minh-thanh

Mechanicboy !
You're right,
I can drill holes as large as 5.5 mm
But  I'll drill the big hole when I make the connecting rod
Steamchick !
Not,  Do you know a formula for that ?
Willyb !
Thanks ! I will..

Hi All !
A Update ::


----------



## Thommo

Hey Than, your machining looks better with every engine you build mate


----------



## minh-thanh

Hi  Thommo !
Thanks !
Are you Mark Thomas ?

Hi All !
A update :


----------



## Thommo

Yes Than, that’s me mate


----------



## minh-thanh

Hi All !
A update :


----------



## Thommo

Looking great mate. Can’t wait to hear it running!


----------



## Steamchick

Sorry, Min. Somewhere in a text book, but I have been too busy to research it. There are 2 basic formulae, one for a pin fitted in the con-rod and rotating at the piston bearings (diagram 4. SIMPLE BEAM- UNIFORM LOAD PARTIALLY DISTRIBUTED ) , one for the pin fitted in the piston and rotating at the con-rod small-end bearing (diagram16. BEAM FIXED AT BOTH ENDS- CONCENTRATED LOAD AT CENTER). 
See: http://www-classes.usc.edu/engr/ce/457/moment_table.pdf 
For Fatigue I would use max calculated stress must be below 0.1% of the proof stress for the pin material.
Of course the bearing loads are relatively easy to calculate.


			http://docshare01.docshare.tips/files/28452/284523662.pdf
		

or:


			https://r.search.yahoo.com/_ylt=AwrJKiDGX_pgjk4A4gB3Bwx.;_ylu=Y29sbwMEcG9zAzIEdnRpZAMEc2VjA3Nj/RV=2/RE=1627050054/RO=10/RU=http%3a%2f%2fdocshare01.docshare.tips%2ffiles%2f28452%2f284523662.pdf/RK=2/RS=jk0cDvO4Og3rYwbU8A0PPZXUkB0-
		


Getting the ratio of piston bearing width to con-rod small-end bearing width is very important for optimum design. 
K2


----------



## GreenTwin

I remember looking at Find's website a long time ago, and as I recall, there were photos of his true injector build.

If my memory is correct, Find said that the injector has to be designed such that the pressure within the engine cylinder forces the injector closed, and the pump pressure forces the injector open.

This situation is similar to a valve on any standard 4-stroke engine, where the valve opens into the cylinder when lifted by the cam, and then closes with the cylinder pressure pushing against it.

I assume that Find uses a light spring to keep the injector valve seated, and the tiny (I guess mushroom-head) valve lifts off it seat when the pump reaches sufficient pressure.

I think this is one of the secrets of making a miniature injector work.

.


----------



## minh-thanh

Hi All ! 
A update :
Head of  Cylinder 
I can't go buy a round aluminum bar
So I made it from a square piece of aluminum


----------



## Thommo

Looking great Than, can’t wait to hear it run mate


----------



## minh-thanh

Hi All !
A update :


----------



## minh-thanh

Hi All !
A update :
I assembled the engine , I don't have a small copper tube, so I used a 6mm copper tube - which is quite large - to test the pump and injectors (I will replace the small copper tube when I buy it).
  with a high pressure oil leak in the coupling, I see oil vapor coming out of the exhaust, which means the injector has injected oil into the cylinder - whether it's good or bad I don't know
 I have a question: the injector will inject when the piston is 20 degrees in front of TDC, so: where will the pump lobe be located ? will it start pumping or in the middle of pumping or ?
 Thanks !


----------



## Mechanicboy

Connect the lever for amount of fuel to the centrifugal regulator and the ekstra lever with spring connected to the lever for amount of fuel. Then the engine are running with right regulated amount of fuel in the right rpm range.


----------



## Peter Twissell

Regarding your injection timing question:
If the system is sufficiently rigid, i.e. no bubbles in the fuel, no movement in the pipework etc., then the injector should open almost immediately when the pump piston begins to move.
If you are controlling pump displacement by raising the piston away from the cam, injection timing will be retarded as position displacement is reduced.

Pete.


----------



## minh-thanh

Mechanicboy said:


> Connect the lever for amount of fuel to the centrifugal regulator and the ekstra lever with spring connected to the lever for amount of fuel. Then the engine are running with right regulated amount of fuel in the right rpm range.


Mechanicboy !
 My first diesel engine, so I just need it running. when it runs i will think of other problems

Pete !

Useful information !
Thank you !


----------



## reichpaul630

minh-thanh said:


> Hi All !
> A update :
> I assembled the engine , I don't have a small copper tube, so I used a 6mm copper tube - which is quite large - to test the pump and injectors (I will replace the small copper tube when I buy it).
> with a high pressure oil leak in the coupling, I see oil vapor coming out of the exhaust, which means the injector has injected oil into the cylinder - whether it's good or bad I don't know
> I have a question: the injector will inject when the piston is 20 degrees in front of TDC, so: where will the pump lobe be located ? will it start pumping or in the middle of pumping or ?
> Thanks !



i'm a bit curious when you say that you "see oil vapor coming out of the exhaust". you should be shooting a *very fine mist*.
the quantity of fuel per stroke should also be very small, only a few milliliters. you may have too large or too coarse of spray
from your injector.  i suggest you "fire" your injector over a glass jar. it must have a very fine mist with no droplets. a proper
injector will make a popping sound when the injector nozzle opens. otherwise, the fuel won't atomize properly. high pressure
and proper nozzle manufacture makes building injectors difficult. (but Find Hansen did find a way.)

your 6mm copper tubing is too large. copper is also "soft" compared to steel tubing, and will affect fuel atomization. smaller
copper (or better, steel)) tubing should improve the performance of your fuel system.

by convention, "20 degrees BTDC" would be the _**start*_* of injection (noszsle opens). the fuel spray will continue until the nozzle
closes. the_* *effective**_ timing is determined by the start of injection, the duration of injection and the injection quantity. i.e. *if* the
fuel is "dumped" through the injector quickly, the *effective* timing will be more advanced, etc. depending on your actual setup, 20
degrees may be a bit much, 5-10 degrees might start easier.

earlier there was some question about how much fuel pressure was needed. my diesel VW has an injection pressure of
3,000 PSI. the newest models use a different system that can achieve 30,000 PSI. at these pressures, pieces of copper
soldered together will not be able to hold that pressure for long. very high pressure plus very good fuel atomization is what
makes a diesel go!

paulr


----------



## minh-thanh

*reichpaul630 !*


reichpaul630 said:


> i'm a bit curious when you say that you "see oil vapor coming out of the exhaust". you should be shooting a *very fine mist*.
> the quantity of fuel per stroke should also be very small, only a few milliliters. you may have too large or too coarse of spray



When I tested : I could smell oil from the exhaust  pipe , but i am not sure it was oil from the exhaust pipe , so i increased the oil pressure a little ( piston stroke at the beginning of the test was the lowest - only increased about 0.5 - 0.7  mm extra piston stroke) to be sure: the oil pump generates enough pressure to open the injector
When I assembled the engine, I noticed that the pressure in the cylinder was quite high so I am not sure if the oil pump created enough pressure to open the injectors.
I only have a 6mm copper tube and I only use it for testing
Yes, I will replace it with a small copper tube when I buy it



reichpaul630 said:


> by convention, "20 degrees BTDC" would be the _**start*_* of injection (noszsle opens). the fuel spray will continue until the nozzle
> closes. the_* *effective**_ timing is determined by the start of injection, the duration of injection and the injection quantity. i.e. *if* the
> fuel is "dumped" through the injector quickly, the *effective* timing will be more advanced, etc. depending on your actual setup, 20
> degrees may be a bit much, 5-10 degrees might start easier.



That's what I'm really thinking about
Thank you !


----------



## Steamchick

The 6mm copper tube is only rated for 6bar - if regular "domestic" pipe - but will have a burst pressure well above that. However, it will be yielding if you attain anything like 50bar... But you want 200 bar pressure in the pipe... - all be it for small pulsations - otherwise you won't attain "atomisation" pressures at the injector. Solder won't hold that. The copper will flex and as it expands you won't get the pressure at the injector.  Go to a scrap yard and get some old steel injector pipes from a diesel car or truck and use that material... cheap - easy to source - the right stuff!
Try and remember: You need 25 bar air pressure in the engine from the adiabatic compression stroke. Just to open the injector you need to exceed that. But to get atomisation you'll need to achieve 100bar plus in the pulsation from the injection pump. The volume is so small you need a very "stiff" pipework and connector system. I.E. THICK walled steel tubing with very small bore.
Have you checked the actual compression you are achieving in the cylinder? Have you checked the pressure you are achieving from the pump?
I think you need to know more so you can direct your efforts accordingly.
But enjoy it! - We are...
K2


----------



## Badhippie

I am wondering how you are getting air flow into the engine. Since a Diesel engine produces no vacuum at all due to the fact there is no throttle plate. A true Diesel engine has to have forced air. 
Thanks
Tom


----------



## Steamchick

Hi Badhippie, I disagree. There are millions of naturally aspirated diesels running around the roads... without superchargers, turbochargers, etc. The "vacuum" (actually partial vacuum) is developed by the piston moving down the cylinder drawing air through the inlet valve. This may be only a fraction of the "vacuum" (partial) seen on petrol engines with a closed throttle - but comparable to the (partial) vacuum when the throttle on the petrol engine is wide open.
Hope this explanation helps... (someone will correct me when I am wrong - they always do. It's just the best way to learn!)
K2


----------



## TonyM

Surely doesn't need forced air for a diesel to work. Air is drawn in through the inlet valve on the induction stroke simply by the downward movement of the piston causing the vacuum.


----------



## minh-thanh

*Steamchick !
*


Steamchick said:


> Go to a scrap yard and get some old steel injector pipes from a diesel car or truck and use that material... cheap - easy to source - the right stuff!



Why didn't i think of that !?? I  will get some old tubes from my friend



Steamchick said:


> Try and remember: You need 25 bar air pressure in the engine from the adiabatic compression stroke. Just to open the injector you need to exceed that. But to get atomisation you'll need to achieve 100bar plus in the pulsation from the injection pump. The volume is so small you need a very "stiff" pipework and connector system. I.E. THICK walled steel tubing with very small bore.
> Have you checked the actual compression you are achieving in the cylinder? Have you checked the pressure you are achieving from the pump?
> I think you need to know more so you can direct your efforts accordingly.


 
Yes, you are right !
I can't buy what I need right now because of the pandemic and travel restrictions
I will find a way...


----------



## Badhippie

You are correct air is  drawn in by the downward stroke of the piston on a 4 stroke Diesel engine. Or on any engine as far as that goes.  But there is nothing there to allow it to build vacuum. Pretty sure in my 30 yrs of building Diesel engines omg it’s getting closer to almost 40 yrs now. I just realized I am getting old.  they will not produce enough air flow without having some sort of a throttle plate to allow it to build. So in other words it would be like a gas engine running wide open throttle and producing almost no vacuum. And with the vast amount of air a Diesel engine needs to run. So what I guess I am saying is there has to be some sort of a restriction in the air intake. And yes before you go there the size of the cylinder and the stroke will help determine the amount of air flow into the engine. This is also why Diesel engine have to have a separate vacuum pump which is either belt driven or gear driven most are gear driven. To run vacuum operated accessories. Is because Diesel engines produce very little vacuum. Sorry if this don’t make any sense it’s 3:30 am here and I am a little drunk and might not be able to write the words correctly that are trying to flow out of my head 
Thanks 
Tom


----------



## Steamchick

No problem Tom. We all have moments when we have a little vacuum in the head...
And my wife could throttle me sometimes, when she wants a vacuum instead of my presence...
K2


----------



## djswain1

Post removed as it duplicated what others have said...


----------



## djswain1

Steamchick said:


> The 6mm copper tube is only rated for 6bar - if regular "domestic" pipe - but will have a burst pressure well above that. However, it will be yielding if you attain anything like 50bar... But you want 200 bar pressure in the pipe... - all be it for small pulsations - otherwise you won't attain "atomisation" pressures at the injector. Solder won't hold that. The copper will flex and as it expands you won't get the pressure at the injector.  Go to a scrap yard and get some old steel injector pipes from a diesel car or truck and use that material... cheap - easy to source - the right stuff!
> Try and remember: You need 25 bar air pressure in the engine from the adiabatic compression stroke. Just to open the injector you need to exceed that. But to get atomisation you'll need to achieve 100bar plus in the pulsation from the injection pump. The volume is so small you need a very "stiff" pipework and connector system. I.E. THICK walled steel tubing with very small bore.
> Have you checked the actual compression you are achieving in the cylinder? Have you checked the pressure you are achieving from the pump?
> I think you need to know more so you can direct your efforts accordingly.
> But enjoy it! - We are...
> K2


Excellent post & advice K2


----------



## Badhippie

Omg I owe everyone an apology. Most of that content was for another site I belong to that was having issues with vacuum operated accessories on a truck. And got shall we say mixed in with this site. Lesson #1 don’t try replying to a chat when it’s 6hrs past your bed time and your belly is full of beer. Or you get what we have here a complete drunken failure. 
Thanks
Tom


----------



## Badhippie

Minh
I think my original question was supposed to be more like this. 
Are you sure you’re getting enough air flow through the intake system for the amount of fuel??? This is just an area that is often overlooked and mis-judged
Thanks 
Tom


----------



## minh-thanh

*Badhippie !*
I do not know
How to know ?


----------



## Badhippie

Minh
Sorry for just getting back to you. It’s been a long time since I have worked on a flow bench. But if I am right on this. I think this is the equation you would use to figure the swept volume of a cylinder. The easiest way if I recall was the volume of air ingested in a cylinder for each rotation of the crank is close to half of the cylinder displacement. This is called the theoretical maximum volume. ( I think) So in other words it should be equal to what we used to call Sweep volume of a cylinder which if I remember 0.7854 x bore x bore x stroke so with that being said you have 1 intake stroke per 2 crank rotations. You have somewhere close to half the cylinder displacement or it’s running at 100% it’s displacement for every 2 rotations of the crank and this is called Volumetric efficiency. Now we both know there are a lot of variables in this intake passages exhaust passages chamber design lot of things can stop a cylinder from reaching 100% efficiency. But with them numbers you can now get the SCFM for the cylinder if it is at 100% efficiency and I think that was SCFM = displacement x rpm / 3456 god I hope that is right it’s been along time btw displacement is in ( ci ) so the 3456 is the product of 1728 that how many cubic inches is in a cubic foot. 
Who said we would never use that math in real life. Lol lol I am sure you can check me on the old interweb. But this is what I have in my old ass notes from a long time ago. When it used to be fun building 2,000 - 3,000 h/p hemi engines hope this helps this can be used with out a flow bench to get some base figures this just should show what the cylinder is capable off. Taking in now with all that **** being said all of the variables would come into play to limit the 100% efficiency as some I mentioned earlier but there is also cam lift, valve over lap, valve size, cam duration. There are so many things that can impact air flow into and out of a cylinder it’s about stupid. But now you should know what your cylinder is capable of ingesting
I know this sounds like a hell of thing to figure out and you would be correct. But its how you figure it. Btw you can convert the SCFM to CFM if that’s easier to understand 
Sorry if this is confusing it’s supposed to be and please by all means check this over because this is from memory and my notes from years past
Thanks 
Tom


----------



## weir-smith

Minh

I have been following this discussion with some interest and there have been some useful comments so I will add my ten cents worth.

When building a model diesel say 6th scale or less, there are some aspects of the combustion cycle that are difficult to replicate in terms of the real thing. Firstly, the pipe work from the injector pump to the injector must have a very small diameter typically 0.5mm or less. In theory you can't compress diesel fuel however in this case you are talking about significantly less than half of a single drop of fuel. If the internal diameter of the tube is large say 6mm the tube simply expands with each pulse of fuel. I used 1.5mm OD (0.25mm ID) stainless steel capillary tube via ebay and tig welded the joints. This worked out well. The other problem you have is, that you can't get the cylinder and cylinder head hot enough to ignite the fuel air mix using just standard diesel. One of the reasons some diesels need glow plugs to get started. The information is on the net re the compression pressure for different types of liquid fuels.

You will find kerosene is significantly less than diesel and further, ether is significantly less again. For a miniature diesel, a mix of kero 70% and ether 30%  makes it quite easy to start. If you want, after the engine is hot, you can switch to straight kero.

As for injection pressure, my testing showed that 1800 to 2000 psi was sufficient to atomise the fuel. You can't see it as such but put some paper in front of the injector. If you can see the spray, it not atomized as such.

I used parts from a cheap commercial pump eg the barrel and plunger for my pump and it would pump up to 3000 psi with out any trouble. For the injector, I used a small commercial pintal type nozzle fitted into a steel body. The best I could ever achieve making my own was about 1200 psi for the pump and a dripping injector at about the same pressure. I tried many variations and they ranged from a total failure to just not good enough.

Just my thoughts from building a miniature diesel.

Bruce


----------



## minh-thanh

Hello Everyone
An update
Because it is not possible to buy small tubes, gauges...
I made one more injector style,


----------



## Lloyd-ss

Minh, That injector looks so nice that it doesn't have to work, LOL. But I hope it does!


----------



## Thommo

I have to agree with Lloyd, that’s a beautiful looking injector. I also hope it works well mate.


----------



## reichpaul630

minh-thanh said:


> Hello Everyone
> An update
> Because it is not possible to buy small tubes, gauges...
> I made one more injector style,



here's a place that might be able to help. not a recommendation/endorsement, whatever. there is
a size shown here HERE that is .005" ID and a .06" OD, rated to about 27000 PSI. the search term
was "stainless steel capillary tube".
LC Stainless Steel Capillary Tubing

i think these will work better for you as another poster said earlier.

ALSO, here's some Bosch stuff i found on my 'puter. i intended to send these earlier.
https://www.youtube.com/watch?v=SqBlqdeP3uE
describes the operation of the Bosch VE11 diesel injection pump, a common distributor type pump.
(18 min.)

this youtube shows the internals of the Bosch VE11, and describes all of the parts (16 mins):
https://www.youtube.com/watch?v=QwVTm2-W-JE

paulr


----------



## minh-thanh

Thanks for the comments and " Like" !
I tested it with compressed air, it's completely sealed,
Again ...Due to the epidemic situation and travel restrictions ... I am not able to buy small tubes and pressure gauges to adjust.
I really hate it but I can't do anything else


----------



## Thommo

minh-thanh said:


> Hello Everyone
> An update
> Because it is not possible to buy small tubes, gauges...
> I made one more injector style,
> View attachment 128740
> View attachment 128741


Hi Than, I was thinking, if you need some small and specific sized tubing. If it’s available in Australia I could get some pieces and mail them to you. If it will help you get the job done and it’s not too expensive I’d be happy to just buy and send it you you for free


----------



## minh-thanh

Hi Thomas !
Thanks mate !
The problem is that the disease in my area is quite complicated, so the transportation of non-essential goods has stopped.
I can buy small tubes in Vietnam , but the problem is travel and transportation is not possible


----------



## Thommo

Hi Than! I’m sorry to hear about the situation over there mate. I’ll make sure you are in my prayers. Take care of yourself and please let me know if I can assist in any way!


----------



## djswain1

Hi Minh-Thanh
I see you have commented on a new thread regarding a model diesel engine, I have replied with some basic info that may be of use to you.






						Injected Diesel 56cc 2 Stroke, Will it ever work?"
					

Yup, I am learning the diesel jargon. It seems like the 2 most common mechanical types that are applicable to the diesel model engines are the (1) unit injector :located in the head, driven by a cam and  rocker arm, with the pump and injector as a single unit, and bypass for excess fuel back to...




					www.homemodelenginemachinist.com
				




Cheers, Dave.


----------



## minh-thanh

Hello Everyone !
An update  :
I bought small diameter pipe
I made a new injector body, and changed it a little
and test
This is probably the type of injector and the way it sprays that I am most satisfied with so far .


----------



## Mechanicboy

minh-thanh said:


> This is probably the type of injector and the way it sprays that I am most satisfied with so far .



Much better atomized fuel. The important is the amount of the injected fuel into the engine.


----------



## Thommo

Hey Than, as an old diesel mechanic I must say that spray pattern looks excellent. The only question I have is have you been able to measure the volume of fuel that you are spraying per cycle? I might be wrong but it looks like a lot of fuel based on the engine size?


----------



## minh-thanh

Hi my friend !


Thommo said:


> The only question I have is have you been able to measure the volume of fuel that you are spraying per cycle? I might be wrong but it looks like a lot of fuel based on the engine size?



I haven't measured the fuel yet
when i try , i also see too much fuel injection ,
Even though I reduce the stroke of the piston   pump, it seems that the amount of fuel is only reduced to about 2/3 per cycle
  Right now, i think i will make a new pump cylinder 1/2 . smaller
The new cylinder with diameter is about 2 mm   diameter
Current cylinder diameter is 4mm

There is 1 problem: i plan to keep the whole 4mm pump, for testing
and make a new pump with a diameter of 2mm
But there's so much to do .


----------



## Thommo

That sounds like the way to go mate. Keep all your test results mate. I’m sure that there will be guys in the future that would be very grateful. You’ll save them a great deal of work. I’m looking forward to hearing the beast run. It will be an awesome achievement


----------



## minh-thanh

Hello Everyone !
An update : 
When I was thinking about ways to reduce fuel  , I realized that I could reduce the   lobe  lift
so I sharpened the lobe, currently the cam lobe only lift about 1.8mm
And :


----------



## Thommo

Hey Than, the volume looks better but now the spray pattern looks a bit uneven (could be the video). Assuming that the spray pattern is ok, I would work on getting a finer mist. Once again it could be ok but I can’t really tell with the video.


----------



## Mechanicboy

Find Hansen diesel engine has a pump stroke at 0,03 mm under idling. It means that you can have a smaller injection nozzle.


----------



## minh-thanh

Mechanicboy said:


> Find Hansen diesel engine has a *pump stroke at 0,03 mm *under idling. It means that you can have a smaller injection nozzle.


Are you sure ???
With my little experience and ability...., I cannot make the injector open in the cylinder with a pressure that produces at 0.03 mm stroke. .,and can't even open the needle with the pressure of the spring in atmospheric pressure


----------



## Mechanicboy

minh-thanh said:


> Are you sure ???
> With my little experience and ability...., I cannot make the injector open in the cylinder with a pressure that produces at 0.03 mm stroke. .,and can't even open the needle with the pressure of the spring in atmospheric pressure



How big are the bore and stroke in your engine? Find Hansen engine has bore 20 mm and stroke 36 mm. Small cylinder volume = small amount of fuel to be injected and vice versa. The small engine need small injector to atomize the fuel better with small amount of fuel than the large injector. Too much fuel or too coarse fuel drops of atomized fuel from the large injector can't work well in the small engine (too wet and difficult to start up the engine).


----------



## Peter Twissell

0.03mm or 30 microns, does sound unlikely.
Remember the oil has a bulk modulus of around 1500 MPa. To generate any significant pressure with 30 microns of piston travel, the volume of oil to be compressed would have to be very small indeed.


----------



## Mechanicboy

Peter Twissell said:


> 0.03mm or 30 microns, does sound unlikely.
> Remember the oil has a bulk modulus of around 1500 MPa. To generate any significant pressure with 30 microns of piston travel, the volume of oil to be compressed would have to be very small indeed.



From Find Hansen homepage


----------



## minh-thanh

I really don't understand with only 0.03 mm of stroke.....
 So I'll try my way.


----------



## Mechanicboy

minh-thanh said:


> I really don't understand with only 0.03 mm of stroke.....




Minh-Tanh..
You wrote in post #76:

_"I just finished designing the engine
Bore : 19 mm , stroke : 38 mm" _

Also near same dimension as a Find Hansen engine who has 20 mm bore and 36 or 44 mm stroke. 
Also you need small diameter pump and small injector nozzle + regulator.

The amount determined by the regulator that the engine runs at a certain speed should have a certain amount of fuel. A certain cylinder volume that goes at a certain speed must have a certain amount of fuel. We can not control this manually without a regulator, not even if we try with a specific pump stroke or the amount to turn on. The regulator is what helps the engine to run smoothly on a certain amount of fuel. As I wrote that Find Hansen used 20 mm bore and 36mm stroke for hot bulb engine and 44 mm stroke for diesel engine due to the compression ratio is not the same in hot bulb engine and diesel engine. Both motors have a 2 mm diameter pump and the stroke length is determined by the regulator to a desired speed range.

The injection nozzle is so small that it atomizes so nicely on small amounts of the fuel pumped in from such a small injection pump. The injector has a spring loaded injector valve, with a valve head angle of 14 degrees and a valve stem 0.90mm thick. The valve stem is treaded so that the spring can be adjusted to the right fuel pressure with one nut, and locked with another nut. Compare that to matches at Find Hansen's injection nozzle, a real masterpiece!

The best one can make an injection nozzle is a watchmaker lathe if the large lathe is too rough and difficult to make such fine and small parts.
Maybe you can ask the watchmaker to make a small and fine injection nozzle?


----------



## minh-thanh

You should try with pump with 2mm and 4mm diameter and with 0.03mm . stroke
  I don't know how to generate oil pressure?? and that pressure is enough to pump into the cylinder??
How to produce a pressure of about 50 bar , 80 bar with a stroke of 0.03 mm??
Can you explain it ?


----------



## Mechanicboy

minh-thanh said:


> You should try with pump with 2mm and 4mm diameter and with 0.03mm . stroke
> I don't know how to generate oil pressure?? and that pressure is enough to pump into the cylinder??
> How to produce a pressure of about 50 bar , 80 bar with a stroke of 0.03 mm??
> Can you explain it ?



To generate the pressure is determined by the spring in the injector and not from the pump. Strong spring generate better atomized fuel and vice versa. Also adjust the spring to generate the oil pressure and get fuel atomized. The oil is not compressible and the nozzle will open at high pressure.


----------



## Vietti

does anyone remember the DUX?  It was a small diesel described in one of the last few issues of MEB.  Probably some really relevant info.  If I remember correctly the injector was made by scratching.

John


----------



## Vietti

Should say the last PRINTED issues.  I believe the builder was  dutch.  John


----------



## Vietti

Well my memory isn't so good.  The construction series for the Dux was in SIC not MEB.

The Author is Martin Alewijn, his 20 year old email is  [email protected]

The series was in SIC starting in Vol 13 No. 78 and was in Vol 14 No 78, Vol 14 No 80, Vol 14 No 81 and concluded in Vol 14 No 82, five parts.

Someone will hopefully suggest how to get back issues.

I personally would not attempt a small diesel without reading this series.  The engine described was about the same size as being discussed.  Of particular interest is his design for a simple injector and pump.  He used a glow plug to aid starting just like some big engines.

I hope this is of some help.  John


----------



## minh-thanh

Mechanicboy !

We will not argue about stroke 0.03 mm
Maybe I'm wrong
So I'll try my way.


----------



## Mechanicboy

minh-thanh said:


> Mechanicboy !
> 
> We will not argue about stroke 0.03 mm
> Maybe I'm wrong
> So I'll try my way.



Read again this: Both motors have a 2 mm diameter pump and *the stroke length is determined by the regulator to a desired speed range*.


----------



## minh-thanh

For you .
 That's all I need !!


----------



## Mechanicboy

minh-thanh said:


> For you .
> That's all I need !!




Minh-Thanh,...

It is allowed to dream, but be realistic and listen to us who can provide the answers to what you need to know based on our knowledge and experience.  Here in the forum, it is nice to be guided to solve the problem and make the engine work with good results of patience and focused on the small important details that must not be overlooked.  For a beginner, there are many pitfalls and expensive to try and fail without a good result.  Do not forget that you made it work with the help of us who guided you to make glow plug engine, model diesel engine with compression screw and the 4 cylinder 4 stroke engine with good results and these model engines ran so well.  In other words, do not give up when you can really make your engine work with injection equipment which is a big challenge and not so easy for others to make and make it work properly in small dimensions.


----------



## minh-thanh

Mechanicboy said:


> , but be realistic and listen to us who can provide the answers to what you need to know based on our knowledge and experience.


I think you're talking about "you", not "us"


Mechanicboy said:


> .  Do not forget that you made it work with the help of us who guided you to make glow plug engine, model diesel engine with compression screw and the 4 cylinder 4 stroke engine with good results and these model engines ran so well.


I'm always welcome to comment, everyone
I learn and get help from so many people , From masters to those* who have never done engines* , from forums , facebook , youtube , google... , and I am always grateful for the comments contribute

back problem : 0.03 mm stroke
The oil volume in the cylinder has a diameter of 2mm with a stroke of 0.03 mm
V = 3.14.r.r.h = 3.14 x 1 x1 x 0.03 = 0.0942 mm3
this can be achieved (??) when the lobe surface finish, the oil loss between the cylinder and the piston, the perfection of shaft, ..... is 0.0000mm , eliminating the vibration   engine running.....
Because all of that will affect 0.03 mm of piston stroke
Watch from the 28th minute of the video, you can see the piston stroke - that is probably the only video where i can see the piston stroke
*and I'm sure it's not 0.03 mm . stroke*


----------



## Mechanicboy

minh-thanh said:


> back problem : 0.03 mm stroke
> The oil volume in the cylinder has a diameter of 2mm with a stroke of 0.03 mm
> V = 3.14.r.r.h = 3.14 x 1 x1 x 0.03 = 0.0942 mm3
> this can be achieved (??) when the lobe surface finish, the oil loss between the cylinder and the piston, the perfection of shaft, ..... is 0.0000mm , eliminating the vibration   engine running.....
> Because all of that will affect 0.03 mm of piston stroke
> Watch from the 28th minute of the video, you can see the piston stroke - that is probably the only video where i can see the piston stroke
> *and I'm sure it's not 0.03 mm . stroke*



You have not understood the whole point of 0.03 mm.
It is not the lifting height of the camshaft itself.
When Find Hansen measured the 0.03 mm pump stroke it was at idle he could observe how big the pump stroke was to be able to run the engine at idle.

Look at it all: For example, the camshaft has a height of 3 mm stroke and the regulator has a wedge that goes in / out between the camshaft and the pump. It is this wedge (red wedge in picture) that changes the pump stroke length from 0 mm (engine is stopped) to a maximum of 3 mm (maximum injection volume at maximum speed). Somewhere between 0 mm and 3 mm, there is a certain amount that is injected into the engine at a certain speed when one puts the regulator in a certain spring force which is connected between the regulator and the lever for regulating the speed.

The pump stroke varies depending on the speed range via the regulator and one controls the speed using the spring force. Tight spring force = high speed and slack spring force = low speed.

The amount injected into the diesel engine is very small in a small engine. The fuel itself has high calories to burn so well in the combustion chamber. Look at the model engine running for a long time on a tank that there is such a small amount that is burned for each engine burns at each combustion stroke.

How is fuel injection measured in the car diesel engine?
Fuel injector size determines how much fuel is able to be injected into the combustion camber by the injector. Normally, fuel injectors are sized by *cubic centimeters per minute* of fuel able to flow through them.

Also in a model diesel engine, there is even much less fuel that is injected into the internal combustion engine than in the car diesel engine.


----------



## Steamchick

Excellent explanation Jens. I am learning a lot.
K2


----------



## TonyM

''You have not understood the whole point of 0.03 mm.
It is not the lifting height of the camshaft itself.
When Find Hansen measured the 0.03 mm pump stroke it was at idle he could observe how big the pump stroke was to be able to run the engine at idle.''

I fully understand, as I am sure Minh does also, Jens graphic description but I have to agree with Minh on this. If you slow the video at 28.2 then, remembering this is running at idle, that pump is moving way more than .03mm / .001''   more like 1-2mm After reviewing the vid again the wedge looks at about the half way mark at the speed it is running. So based on the wedge being 0-3mm, the pump piston movement is about 1.5mm at tickover.


----------



## Mechanicboy

TonyM said:


> ''You have not understood the whole point of 0.03 mm.
> It is not the lifting height of the camshaft itself.
> When Find Hansen measured the 0.03 mm pump stroke it was at idle he could observe how big the pump stroke was to be able to run the engine at idle.''
> 
> I fully understand, as I am sure Minh does also, Jens graphic description but I have to agree with Minh on this. If you slow the video at 28.2 then, remembering this is running at idle, that pump is moving way more than .03mm / .001''   more like 1-2mm After reviewing the vid again the wedge looks at about the half way mark at the speed it is running. So based on the wedge being 0-3mm, the pump piston movement is about 1.5mm at tickover.



The pump stroke varies all the time depending on the speed and load so there is no fixed pump stroke in a diesel engine that it can go far down to the lowest pump stroke to the highest pump stroke in a speed range. If you load a motor, then it gives the larger pump stroke, you let it run unloaded, eg drive a car down, then the pump stroke becomes smaller or zero fuel. The same goes for the engine faster than it should run, then the pump stroke becomes smaller and vice versa. See at the movie of the Find Hansen's engine: The regulator, it never stands still. It regulates all the time.


----------



## minh-thanh

Mechanicboy .
I know you want to help, but right now: sit down, have a coffee or a beer, calm down and think !!


----------



## Steamchick

Gentlemen, I suspect you are on the same lines, but at different perspectives. (I'm just as likely to get this wrong, as right, but here goes....). I think the perspective of the fuel pump with variable stroke - connected to a governor - says the pump has a "minimum" stroke that it will use with governor adjusted to "idle"... but that isn't Minh Thanh's demonstration. It is the demonstration in the Utube videos.
However, Minh Thanh is demonstrating that he can achieve an injector that will work "at some pressure and volume delivery" - likely to be the maximum stroke - ergo volume - that the pump can deliver.
Maybe the next step is for Minh Thanh to develop a means of adjusting the stroke of his fuel pump to see what minimum speed and pressure it can deliver a "good spray" ??
There is one caveat that may or may not affect all this: The demonstration of a hand (or powered) pump showing the spray pattern (I learned using a Lucas CAV hand pump back in the 1960s) only demonstrates the pattern of fuel spraying into still atmosphere. When introduced into an engine, with variable speed and pump delivery (stroke controlled), the internal cylinder pressure is going to be +25bar - or whatever - and the much denser air will have a tremendous amount of turbulence or swirl generated by the shapes of the surfaces of the changing volume of the cylinder as the piston moves. So the "hand-pump" test does a few things:

It determines a pressure at which the injector opens (Generally, the higher the better). As seen on the pressure gauge - as I remember from 55 years ago...?
It shows the spray pattern, so you can measure the "angle of the cone" - I was taught that for a multi-cylinder diesel, it was more important to match injectors for pressure, then angle of cone, than anything else, for a smooth running engine.
It shows the spray pattern, so you can measure the "uniformity of spray of the cone". You don't want it to be "all on one side" - or with "gaps in the cone". - These would be classed as NO GOOD, and re-worked until OK or scrapped.
You can check for leakage by pumping to 3/4 (??? - I can't remember, but an expert will surely advise?) of the "spray pressure", holding for a minute, then checking how many drips have fallen from the injector. NONE is good.
But back to the volume delivered... Minh Thanh, - I think (from the thread above) you do need to consider making a 2mm diameter pump instead of the 4mm you have made. Then measure delivery pressure from the injector and specific rpm, as well as the delivery volume. Then you will have numbers to help the experts advise you properly.

I hope this helps, and apologise if I am completely "off-target" or inaccurate with my remarks. I am an amateur in the subject of  "diesel injection"... maybe the experts can help us all understand this subject in correcting my diatribe.
Stay happy! - Life is too short and too little Love, Laughter is most important.
K2


----------



## ajoeiam

I believe its a magazine but what is 'SIC'?
(Referring to an earlier post in this thread.)


----------



## Mechanicboy

Steamchick said:


> However, Minh Thanh is demonstrating that he can achieve an injector that will work "at some pressure and volume delivery" - likely to be the maximum stroke - ergo volume - that the pump can deliver.
> Maybe the next step is for Minh Thanh to develop a means of adjusting the stroke of his fuel pump to see what minimum speed and pressure it can deliver a "good spray" ??
> There is one caveat that may or may not affect all this: The demonstration of a hand (or powered) pump showing the spray pattern (I learned using a Lucas CAV hand pump back in the 1960s) only demonstrates the pattern of fuel spraying into still atmosphere. When introduced into an engine, with variable speed and pump delivery (stroke controlled), the internal cylinder pressure is going to be +25bar - or whatever - and the much denser air will have a tremendous amount of turbulence or swirl generated by the shapes of the surfaces of the changing volume of the cylinder as the piston moves. So the "hand-pump" test does a few things:
> 
> It determines a pressure at which the injector opens (Generally, the higher the better). As seen on the pressure gauge - as I remember from 55 years ago...?
> It shows the spray pattern, so you can measure the "angle of the cone" - I was taught that for a multi-cylinder diesel, it was more important to match injectors for pressure, then angle of cone, than anything else, for a smooth running engine.
> It shows the spray pattern, so you can measure the "uniformity of spray of the cone". You don't want it to be "all on one side" - or with "gaps in the cone". - These would be classed as NO GOOD, and re-worked until OK or scrapped.
> You can check for leakage by pumping to 3/4 (??? - I can't remember, but an expert will surely advise?) of the "spray pressure", holding for a minute, then checking how many drips have fallen from the injector. NONE is good.
> But back to the volume delivered... Minh Thanh, - I think (from the thread above) you do need to consider making a 2mm diameter pump instead of the 4mm you have made. Then measure delivery pressure from the injector and specific rpm, as well as the delivery volume. Then you will have numbers to help the experts advise you properly.



Steamchick ..

The cone and length varies from nozzle to nozzle depending on the type of diesel engine built as a direct injection, pre-chamber or vortex chamber diesel engine.

Semi-diesel engine is injection nozzle difference from diesel engine injection nozzle as it is not high pressure that opens the nozzle needle, adjustable nozzle works the same principle as hand spray where you can regulate the nozzle from thin jet to fine atomized spray and the fuel is already heated by hot bulb to develop into fuel steam before combustion starts. Thin jet directly in the cylinder at high speed so that the hot bulb does not get too hot and leads to engine knocking under load and a nice atomized spray to idle to keep the hot bulb warm (see away from Find Hansen who used the same nozzle in both model engines Diesel engine and semi-diesel engine as the semi-diesel motors are too small to have an adjustable nozzle).

Leak test: hold the test pump up to the opening pressure 1-2 bar before the opening pressure and let it stand for a few minutes: if it drips, it is not completely tight nozzle and must have a new nozzle needle set. No drip = the nozzle needle is tight and everything is in order. Nozzle with the right opening pressure you can hear "RRR - RRR - RRR" every time you pump at a certain speed on test pump (I have worked and still work as a car mechanic for over 30 years).

As you just wrote about 4 mm pump diameter, it's way too big. We have such Norwegian-produced SABB semi-diesel engine, they have a pump that has a diameter of 6 mm, there is only a 2 mm difference between Thanh own pump and pump in the SABB semi-diesel engine. SABB Type C has a bore of 120 mm and a stroke of 150 mm and uses 6 mm diameter and the stroke is not large, varies from about 3-4 to 6-7 mm depending on the speed range. 4 mm pump provides too much fuel for a small engine and much more difficult to regulate the stroke to get a desired amount to inject into the engine as a much shorter stroke is required than a 2 mm bore pump. With a smaller pump diameter, it becomes a larger range to regulate the amount from the smallest to the largest stroke. Because a pump with a small diameter with a larger stroke length makes it easier to regulate from the lowest to the highest amount of fuel.

And the nozzle does not atomize so well on a reduced camshaft profile of 1.8 mm. This means that a much smaller nozzle about as small as a match as you can see in the photo at Find Hansen is needed for it to atomize better on a smaller amount of fuel.

Thanh ..
The injection nozzle size is determined by the pump size. So you have gained new experience why it does not atomize so well at the smaller amount of fuel needed in a small engine after you had reduced to 1.8 mm pump height. 4 mm diameter and reduced stroke does not work as well on a nozzle that is larger than Find Hansen's nozzle.


----------



## minh-thanh

Mechanicboy said:


> The injection nozzle size is determined by the pump size. So you have gained new experience why it does not atomize so well at the smaller amount of fuel needed in a small engine after you had reduced to 1.8 mm pump height.


I found the cause : Ball valve spring is too weak,
sometimes the outlet pressure is very weak. I replaced the springs with a new one and it sprays so much better.
I just thought that the springs just holding the ball in place with light pressure would be enough, but I was wrong 
  1.8 mm stroke is max stroke, With the latest video the piston stroke is less than 1mm ( about 0.8 mm , but I'm not sure )

I will try with diameter 4mm, 3mm and 2mm .
because I don't know how well the pump I do? does it generate enough pressure...
With the injectors, I'm making 2 new injectors, their size will be smaller like no.2, no 3
  There's only one way to know: trial and error


----------



## Mechanicboy

minh-thanh said:


> I found the cause : Ball valve spring is too weak,
> sometimes the outlet pressure is very weak. I replaced the springs with a new one and it sprays so much better.
> I just thought that the springs just holding the ball in place with light pressure would be enough, but I was wrong
> 1.8 mm stroke is max stroke, With the latest video the piston stroke is less than 1mm ( about 0.8 mm , but I'm not sure )
> 
> I will try with diameter 4mm, 3mm and 2mm .
> because I don't know how well the pump I do? does it generate enough pressure...
> With the injectors, I'm making 2 new injectors, their size will be smaller like no.2, no 3
> There's only one way to know: trial and error



In outlet, the spring must be strong (not stronger than injector needle spring), but weak spring in suction side due limited by force of vacuum created by pump.


----------



## Vietti

SIC magazine was a fantastic source for those interested in internal combustion engines.  SIC stands for "Strictly Internal Combustion".  The founder/editor was Bob Washburn.  As the title suggests its only about internal combustion with no clocks or steam, etc.

I had forgotten how good it was till I went looking for the info on the Dux.  May have to sit down and read the whole series again!  Well worth the effort to get copies.

Does anyone know how to get copies??

John


----------



## Steamchick

Thanks Jan.
K2


----------



## Steamchick

minh-thanh said:


> 1.8 mm stroke is max stroke, With the latest video the piston stroke is less than 1mm ( about 0.8 mm , but I'm not sure )
> 
> I will try with diameter 4mm, 3mm and 2mm .
> because I don't know how well the pump I do? does it generate enough pressure...
> With the injectors, I'm making 2 new injectors, their size will be smaller like no.2, no 3
> There's only one way to know: trial and error



Hi Minh Thanh,
As "the ancients" found out when throwing rocks at each other..... You have your first marker - the 4mm diameter pump ram.
Next make the smallest you can: 2mm diameter or less? then  compare calibration of the smallest volume of fuel the pump will deliver (I.E. the pump variable stroke device adjusted to the minimum that works the injector successfully), with the "expected volume" - from the advice from others above. Then a simple comparison will tell you:

If the smallest you can make is small enough, 
if the smallest you can make is large enough - at max stroke - for the max. fuel you need for the engine you are making.
Remembering that delivery volume is proportional to the SQUARE of the diameter, you can determine the cross-sectional area of ram to meet the minimum fuel volume you need (for idling the engine) and the max stroke that that diameter ram needs to get the max. fuel you need.
Then you can make the pump to the required sizes.
This empirical method should save a lot of "trial, error, frustration and disappointment, and time, before success is achieved.
It is called "Engineering": Determining where you are going by "Thinking" - before setting out on the journey - then "re-thinking" the details of each next step with the information gathered from the previous step. ("Engineering" is "problem solving" - the "application of Ingenuity").
A tip from NASA (possibly mis-quoted?): "Nobody ever "succeeded" by making a rocket and just "launching it, to see where it would go". But the "Engineering method", of "calculating what is needed", then confirming with some simple tests, before designing and making the real rockets to the determined size, enabled NASA to put a man on the moon and bring him home safely...."
Another quote: "Engineering brings order to evolution, so (many) evolutionary steps can be jumped". (or something - can't remember who taught me that one!)
Hope this helps,
K2


----------



## minh-thanh

Hi All !
Very useful information :


----------



## Mechanicboy

You got about the same answer as here and the other forum when we talked about pump diameter and stroke of a certain size of cylinder volume in the engine.

In fact, the stroke during operation at a certain speed is never a fixed stroke as it varies all the time in a range from the lowest to the maximum stroke controlled by the centrifugal regulator, let us say: at stop the pump stroke is 0 mm and the maximum pump stroke at 1.5 mm, then the diesel engine in an area for example goes somewhere between 0.3 mm and 0.5 mm in a moderate speed with a slightly tight regulator spring, one increases to the desired speed, for example close to the top speed by tightening a little more regulator spring, then it can be between 0.9 at the lowest to the highest 1.2 mm. The pump stroke length is determined by the regulator spring and centrifugal regulator depending on the engine speed and the regulator is never in a certain position, it varies all the time as I had written in a previous post.

When making a pump stroke determined by the wedge between the pump and the cam: Wedge that has a pitch starting from one end 0 mm and up to 1.6-1.7 mm at the other end. Cam disc lift height 1.7 mm which is the maximum as you never reach the 1.7 mm stroke as you can control the speed range yourself via the regulator. Choose a spring that is weak and try until you can regulate from minimum to maximum speed, the engine does not go to maximum speed, replace to stronger springs and try again if you reach the desired speed range. Excessively strong springs are not easy to regulate from low speed to maximum speed, in the worst case the engine can accelerate until it is eventually destroyed.


----------



## minh-thanh

Last word, I will update until I can get the engine running
 If the engine can run , and can be damaged at too high a speed... I don't care . I just need it running !
  I hate arguing, discussing what I don't know and have no experience with
  I'm sure everyone was disgusted reading this thread, I'm sorry !


----------



## GreenTwin

I may have already mentioned this, but it seems like I saw a video one time on Find Hansen's diesel injector, and he said the pressure inside the cylinder has to force the injector closed, and the cam forces the valve open.
I think his valve is like a poppet valve on a standard 4-stroke engine, but tiny.

He said this was the only way to get the valve so seal correctly.

I may have to try a hot-bulb diesel, since it would probably be easier to get it running then have to design an injector.
I don't think Find's injector is that complex though.
I have seen photos of it, and I seem to recall that he had a pretty minimal spring on it.

Good luck everyone with your diesel endeavors.

.


----------



## Steamchick

GreenTwin said:


> I may have to try a hot-bulb diesel, since it would probably be easier to get it running then have to design an injector.
> I don't think Find's injector is that complex though.
> I have seen photos of it, and I seem to recall that he had a pretty minimal spring on it.
> Good luck everyone with your diesel endeavors.


You could "cheat" with the hot-bulb and have a model aircraft glow-plug screwed into the hot-bulb... Not exactly true to full size, but using a glowing element inside a hot bulb chamber should give basically the same ignition? Only needs a 1.5V battery to start, then stays hot from continued firing? - As aircraft glow-plug engines run on 50% kerosene/oil, that's close to the fuel you'd probably use on a hot-bulb engine? - But just "an Idea" from an "outsider with no experience".
K2


----------



## Thommo

Steamchick said:


> You could "cheat" with the hot-bulb and have a model aircraft glow-plug screwed into the hot-bulb... Not exactly true to full size, but using a glowing element inside a hot bulb chamber should give basically the same ignition? Only needs a 1.5V battery to start, then stays hot from continued firing? - As aircraft glow-plug engines run on 50% kerosene/oil, that's close to the fuel you'd probably use on a hot-bulb engine? - But just "an Idea" from an "outsider with no experience".
> K2



Hi Steamchick, FYI gloplug engines run on methanol/castor oil and sometimes added nitromethane, not kerosene. Miniature compression ignition engines most often are run on ether / castor oil.


----------



## Mechanicboy

Thommo said:


> Miniature compression ignition engines most often are run on ether / castor oil.


Hehehe, Thommo..
Castor oil is a lubricant for the model engine. Also the model diesel engine with variable compression are running on kerosene/ether. Ether is a igniter for kerosene.


----------



## Steamchick

Thanks for the correction Thommo. It was just an idea, but my memory from 50 years ago is not perfect, obviously!

K2


----------



## Thommo

Mechanicboy said:


> Hehehe, Thommo..
> Castor oil is a lubricant for the model engine. Also the model diesel engine with variable compression are running on kerosene/ether. Ether is a igniter for kerosene.


----------



## minh-thanh

Hi All !
It lives, 
although still need to improve, but that's what i need right now


----------



## Thommo

Well don Than! I had no doubt that you would get the girl running, but she looks and sounds great. You’re a talented man mate


----------



## minh-thanh

Thanks for the "likes" and compliments
  I put a lot of oil in the engine to prevent damage to the pistons and cylinders when the engine warms up ( I'm not sure  ) because I didn't install the water pipes
  so when the engine runs it bleeds oil


----------



## Thommo

Hey, it’s a prototype and a miniature diesel mate. Give yourself some credit Than, there are a lot of model engine builders out there that wouldn’t have a go at building a production diesel, much less build one to their own specs (albeit with alot of good advice from this forum) and get it to run nicely! I have no doubt that once you setup the cooling system and iron out the kinks, she will be awesome!


----------



## minh-thanh

*Hi Thommo , *my friend* !!*

If anyone wants to build this diesel engine, I will edit the drawings to make them realistic and sell drawing


----------



## Thommo

Hi Than, I don’t have the time to build anything at the moment, unfortunately! However if you do edit your drawings I might be interested in getting a copy for use in the future. Cheers


----------



## awake

Congratulations! Exciting to see a model diesel running. Yes, I would be interested in the plans!

You may have mentioned this earlier in the thread, so forgive me if this is a repeat - are you running this on auto diesel, or kerosene, or ??


----------



## Steamchick

I may just buy some plans!
K2


----------



## Nerd1000

I would also be interested in a set of plans.


----------



## minh-thanh

Hi All !
Sorry for the late reply, i have to go out today
I use: 1 kerosene + 1 ether
I forgot to buy castor oil so I added 1/3 W20
Start with room temperature
This video  I try with only kerosene  
Heat the cylinder head with the torch for about 10 seconds


----------



## ajoeiam

minh-thanh said:


> Hi All !
> Sorry for the late reply, i have to go out today
> I use: 1 kerosene + 1 ether
> I forgot to buy castor oil so I added 1/3 W20
> Start with room temperature
> This video  I try with only kerosene
> Heat the cylinder head with the torch for about 10 seconds





Will it run on #2 diesel?


----------



## minh-thanh

ajoeiam said:


> Will it run on #2 diesel?


 
I don't know because I haven't tried
  I think the engine can run with only kerosene is fine for me
I am measuring the pressure in the cylinder and pump ...to do data


----------



## ajoeiam

minh-thanh said:


> I don't know because I haven't tried
> I think the engine can run with only kerosene is fine for me
> I am measuring the pressure in the cylinder and pump ...to do data



Hmmmmmmmm - - - - you did say you were building a diesel engine - - - not a compression ignition engine - - - yes?


----------



## minh-thanh

ajoeiam said:


> Hmmmmmmmm - - - - you did say you were building a diesel engine - - - not a compression ignition engine - - - yes?


So ....diesel engine must use diesel oil ??


----------



## ajoeiam

minh-thanh said:


> So ....diesel engine must use diesel oil ??



Not necessarily must but kerosene is much more like a #1 diesel and something that only runs on #1 diesel isn't practical if #1 diesel is impossible to find for 5 to 8 months of the year. 
So if I have a small engine - - - - I might call it a SVO engine when I'm running it on SVO but it might be a diesel engine at its root. 

I guess what I'm saying is that you haven't finished with the design challenges on creating a diesel injector yet. 
AIUI if I can't use commonly available fuels - - - well then that isn't a commonly available fuel engine. 

Your thread has been looking at the challenges of getting a good injection of fuel for a diesel engine. 
As soon as you're adding any amount of ether - - - - well that's a great starting assist but its also a tricky tool. 
Even slightly incorrect usage of ether can be quite hard on your engine and maybe even on your person.


----------



## Mechanicboy

Running the dieselengine with ether added in kerosene is not cheap fuel economy. It means the injector must atomize the fuel so very smaller drops to heat up quickly to ignite due ignition lagg (The time from the atomized fuel is leaving the injector to the fuel is ignited in the length of time). Find Hansen used turpentine or kerosene with 2% two stroke engine oil to lubricate the pump/injector.


----------



## minh-thanh

ajoeiam said:


> Not necessarily must but kerosene is much more like a #1 diesel and something that only runs on #1 diesel isn't practical if #1 diesel is impossible to find for 5 to 8 months of the year.



I think kerosene is easy to get! ?? or am i wrong?
  I don't think storing some kerosene is an inconvenience or difficulty...



ajoeiam said:


> Your thread has been looking at the challenges of getting a good injection of fuel for a diesel engine.
> As soon as you're adding any amount of ether - - - - well that's a great starting assist but its also a tricky tool.
> Even slightly incorrect usage of ether can be quite hard on your engine and maybe even on your person.


That's the problem so I want to use kerosene
Every engine I do I try to use easy-to-find fuel like gasoline, kerosene or gasoline +  oil w


----------



## minh-thanh

Mechanicboy said:


> Running the dieselengine with ether added in kerosene is not cheap fuel economy.


It's not a matter of cheap, but it's really hard to buy and seems seems more toxic than if you just use kerosene


----------



## awake

Looks like it runs very happily on kerosene! I'm going to venture a guess that it would also run just fine on #2 diesel ... and might even run on a range of other oils as well. My dad talks about engines that they had to start on one specific fuel, but then could switch over to just about anything flammable to run. Maybe that would be true for this engine?

In any case, whether it "only" ever runs on kerosene, I am very impressed. The key is that you successfully mastered the pump and injector!


----------



## minh-thanh

awake said:


> Looks like it runs very happily on kerosene! I'm going to venture a guess that it would also run just fine on #2 diesel ... and might even run on a range of other oils as well. My dad talks about engines that they had to start on one specific fuel, but then could switch over to just about anything flammable to run. Maybe that would be true for this engine?
> 
> In any case, whether it "only" ever runs on kerosene, I am very impressed. The key is that you successfully mastered the pump and injector!




I'm really surprised with how it can run
The way it sprays...
Perhaps , with my little experience and knowledge of engines , including full size and model engines : It really took me by surprise .
  The way it runs with kerosene+ether+oil w so I thought it would be fine with only kerosene, so I tried it with kerosene and warmed the cylinder head with a torch for about 10 seconds and : RUN
   What I can say: *"I can do it and you can too"*
Only thing is you are patient enough!?


----------



## Mechanicboy

minh-thanh said:


> and warmed the cylinder head with a torch for about 10 seconds and : RUN



How big is the compression ratio in your engine? At higher compression ratio is developing higher temperature. 
If the high compression ratio is high enough, then there is the problem of good atomization of the fuel for the engine to be able to start up without heating the cylinder head.  By heating the cylinder head, you make the fuel evaporate and ignite more easily at start-up. Injection timing also affects the engine to be able to start easily and without creating engine knocking during normal operation.


----------



## Thommo

You might find kero is easier to find in your country than others mate. For example kero is quite expensive over here in Australia as it’s only available in 1 or 2 litre bottles. It used to be available at the bowser in service stations years ago but it’s not used all that much here anymore.


----------



## Nerd1000

Mechanicboy said:


> How big is the compression ratio in your engine? At higher compression ratio is developing higher temperature.
> If the high compression ratio is high enough, then there is the problem of good atomization of the fuel for the engine to be able to start up without heating the cylinder head.  By heating the cylinder head, you make the fuel evaporate and ignite more easily at start-up. Injection timing also affects the engine to be able to start easily and without creating engine knocking during normal operation.


Pretty much every car or utility sized modern diesel uses some kind of glowplug to aid cold starting, so it's no surprise that minh-thanh's model needs a bit of preheating as well.

Makes me wonder if a normal glow plug from a model aeroplane engine would a work for starting a model diesel.


----------



## minh-thanh

Mechanicboy said:


> How big is the compression ratio in your engine? At higher compression ratio is developing higher temperature.
> If the high compression ratio is high enough, then there is the problem of good atomization of the fuel for the engine to be able to start up without heating the cylinder head.  By heating the cylinder head, you make the fuel evaporate and ignite more easily at start-up. Injection timing also affects the engine to be able to start easily and without creating engine knocking during normal operation.


 
theoretically : about 15 - 1
  Increase the compression ratio...I know, but I wasn't planning on using kerosene at first, kerosene was just a way I wanted to find out   the engine could be....


----------



## minh-thanh

Thommo said:


> You might find kero is easier to find in your country than others mate. For example kero is quite expensive over here in Australia as it’s only available in 1 or 2 litre bottles. It used to be available at the bowser in service stations years ago but it’s not used all that much here anymore.


Kerosene Heating Fuel 1 Litre | Sydney Solvents
It costs almost the same as nitro fuel  
  Is it easier to find than ether anyway, or am I wrong again ?
I'm not in your country so I don't know 



Nerd1000 said:


> Makes me wonder if a normal glow plug from a model aeroplane engine would a work for starting a model diesel.




I also had the same question
  It's used for nitro so I don't know if it's ok with kerosene or diesel


----------



## Mechanicboy

minh-thanh said:


> theoretically : about 15 - 1
> Increase the compression ratio...I know, but I wasn't planning on using kerosene at first, kerosene was just a way I wanted to find out what the engine could be....



Increase the compression ratio one step up and try until it is able to ignite the fuel of its own heat from compression.  Find Hansen diesel engine has a compression ratio of 20: 1 and injection begins at 40-45.  You must test how far the engine can inject before TDC without getting an ignition knock.  Drops of fuel need time to be heated until it becomes self-igniting and gets full combustion just before TDC.


----------



## minh-thanh

Mechanicboy said:


> Find Hansen diesel engine has  injection begins at 40-45.


 What is the fuel used ? and are you sure ?


----------



## Mechanicboy

In fact the compression ratio is not same in large , medium and small diesel engine due pressure vs volume is difference in these engines. In the large ship engine compression ratio lower than mediun and small diesel engine.


----------



## Mechanicboy

minh-thanh said:


> What is the fuel used ? and are you sure ?



See in his website, there is well written about fuel:  Kerosene--Petroleum, mixed with 2 % mineral two--stroke oil.

 And timing: The system enable the ignition timing to be changed about
15 crankshaft degrees with the lever, injection is set on a between 40-45 degree.


----------



## Mechanicboy

minh-thanh said:


> and are you sure ?



Here is my work place, worked since 1993..  



Your browser is not able to display this video.


----------



## Mechanicboy

Ser at this engine how to set timing.. 
Sorry I wrote wrong about 40-45 degrees before TDC at Find Hansen's engine, should be between 45 and 55 degrees before TDC.  His diesel engine is set at 45 degrees before TDC can set up to 55 degrees, but the lever with excenter at the fuel pump (see at the movie) can be adjusted 15 degrees in the area where it runs best without getting an ignition knock.  So you have to try out how big the angle is before TDC it goes best and easy to start up without ether in fuel and heating of the cylinder head.


----------



## ajoeiam

Nerd1000 said:


> Pretty much every full sized modern diesel uses some kind of glowplug to aid cold starting, so it's no surprise that minh-thanh's model needs a bit of preheating as well.
> 
> Makes me wonder if a normal glow plug from a model aeroplane engine would a work for starting a model diesel.



Please provide a reference for your assertion. 

To my knowledge modern semis don't have any kind of glow plugs. 
Now guys that run in northern climes do have coolant heaters but that's a different thing all together!


----------



## ajoeiam

Mechanicboy said:


> How big is the compression ratio in your engine? At higher compression ratio is developing higher temperature.
> If the high compression ratio is high enough, then there is the problem of good atomization of the fuel for the engine to be able to start up without heating the cylinder head.  By heating the cylinder head, you make the fuel evaporate and ignite more easily at start-up. Injection timing also affects the engine to be able to start easily and without creating engine knocking during normal operation.



I ran a '80 Rabbit diesel for many years and wish I still had it!!!!!!!!!!!
That was 23:1 compression IIRC. 
That engine had glow plugs - - - some have intake air heaters. Haven't run the second enough so that I would want to have to choose between. 
The higher the compression the higher the economy. 
The higher the compression the higher the level of NOx produced. 
That's why more modern engines are all getting to some low compression levels (IIRC to 9:1 in fact which is upper end spark ignition country!)..


----------



## Steamchick

Nerd1000 said:


> Pretty much every full sized modern diesel uses some kind of glowplug to aid cold starting, so it's no surprise that minh-thanh's model needs a bit of preheating as well.
> 
> Makes me wonder if a normal glow plug from a model aeroplane engine would a work for starting a model diesel.


I reckon it would, as that is the basis of every hot-spot device since blow-lamp heated hot bulbs....
K2


----------



## Steamchick

Mechanicboy said:


> Increase the compression ratio one step up and try until it is able to ignite the fuel of its own heat from compression.  Find Hansen diesel engine has a compression ratio of 20: 1 and injection begins at 40-45.  You must test how far the engine can inject before TDC without getting an ignition knock.  Drops of fuel need time to be heated until it becomes self-igniting and gets full combustion just before TDC.


Let us not forget that Mr Ricardo developed the "pre-combustion chamber, or Indirect injection"  to overcome problems of direct injection and associated difficulties. 
But modern engines use a common rail at 3 to 5 bar, with piezzo- electric injectors that boost injection pressure many times more than the simple injection pump that Ricardo and Minh-thanh is using...
K2


----------



## minh-thanh

Steamchick said:


> Let us not forget that Mr Ricardo developed the "pre-combustion chamber, or Indirect injection"  to overcome problems of direct injection and associated difficulties.
> .
> K2



I was thinking about this too .
  Do you know how much more effective it can be ?


----------



## Nerd1000

ajoeiam said:


> Please provide a reference for your assertion.
> 
> To my knowledge modern semis don't have any kind of glow plugs.
> Now guys that run in northern climes do have coolant heaters but that's a different thing all together!


I should correct that to 'car and utility size' diesel. I guess large displacement diesels have less need for preheating due to surface area: volume differences.


----------



## Mechanicboy

Steamchick said:


> But modern engines use a common rail at 3 to 5 bar, with piezzo- electric injectors that boost injection pressure
> K2



3 to 5 bar??? Not correct, common rail diesel engine has a maximum 1200-1500 bar. To start up the engine 200-250 bar and normal use can be varied between 300-500 bar depending on the brand of common rail diesel engine.


----------



## Mechanicboy

To find correct compression ratio to get high air temperature to ignite the fuel (kerosene autoignition approximately 295 degree celsius) then you need higher heat temperature who are more than 295 C, let us say 300-350 degree to start the engine without to heat up the cylinder head or use ether, then read here the link how to calculate and find the correct compression ratio if you want higher temperature than autoignition of the kerosene.. Or the other alternative instead calculate: Increase compression ratio with thickness of cylinder head gasket and try how easy the engine will start up.

Calculating heat of compression?


----------



## Mechanicboy

Found the compression calculator in this link Compression Ratio Calculator (Static and Dynamic)

Use syringe with 1 or 2  milliliter/cubic centimeter with needle + fluid to measure how much are milliliter/
cubic centimeter in the combustion camber with piston on TDC.
Milliliter = Cubic centimeter.

As you wrote your engine has about 15:1, also the engine has about 0,77 cubic centimeter, then you can adjust the height of gasket and measure how much is the compression ratio with measured amount of milliliter or cubic centimeter. If you need 20:1, then the combustion camber will take 0,567 milliliter (nearest 0,57 milliliter).

Note: The fluid must not be higher than the edge of the hole in the combustion camber where the injector will be there.

0,77 ml and 0,567 ml are not very big difference in volume, then add thickness in millimeter in the calculator "Head gasket thickness(t)" + "Gasket bore (g)" to learn how thick you need to set the required compression ratio in your engine.

With fixed 0,5 cc (without gasket) in combustion camber with the thickness of gasket will give the compression ratio:

0,96 mm gasket --> 14,95:1
0,24 mm gasket --> 19.95:1


----------



## Steamchick

Mechanicboy said:


> 3 to 5 bar??? Not correct, common rail diesel engine has a maximum 1200-1500 bar. To start up the engine 200-250 bar and normal use can be varied between 300-500 bar depending on the brand of common rail diesel engine.


Thanks for the correction... 
K2


----------



## Steamchick

Just browsing the web... as when I worked in the factory lab, my colleagues made diesel fuel for exacting test purposes by blending a base oil (Paraffin/Kerosene?) with a "10%" cocktail of napthaline stuff, and other aromatic stuff, and some lubricating oil.... I don't know the recipe but one single jar of stuff was the strong aromatic smell of DERV you get from fresh pump fuel. I noticed that some Derv I have had in the garage for a few years, no longer has the sharp aromatic smell, and I was told that the chemical was the bit that made DERV easier to ignite when injected. (I'm sure someone will know the stuff?).
More info... https://www.chevron.com/-/media/chevron/operations/documents/diesel-fuel-tech-review.pdf

I saw a TV presentation where to use cooking oil in a diesel car, they added a cup-full (250ccs?) of "Turps substitute" to each Imperial gallon (4.5Litres) of cooking oil... "for easy starting".... 
SO knowing that road fuel has additives for "easy starting" and "home-made" alternative fuels need the same, maybe the arguement about Minh-Thahn's using a bit of Ether in the paraffin for easier running isn't such an issue? 
I would suggest that any way the the ignition is initialised by the heat of compression qualifies as a "diesel" combustion - defined by the combustion cycle determined by Rudolf Diesel I.E. 


			https://www.mechanicalbooster.com/wp-content/uploads/2017/10/Dieselcycleworkingprocess-e1591892297266.png?ezimgfmt=ng:webp/ngcb20
		


 Should this be assisted by a "hot-zone" in the engine caused by a hot glow-plug (even when not electrified) or by a "special zone" in the combustion chamber (such as the Ricardo pre-combustion injection chamber?) it still qualifies as "a diesel" as without the major heating of the gas by compression, the ignition of the fuel-air mix cannot be created.
Considering that "Diesels" (compression ignition engines) run on everything from Ether-paraffin mixes (as for model aircraft - without glow-plugs) through to heavy oils that need steam/electrical pre-heating in order to flow in the pipework and injectors (as used on large ships), then maybe a comment about the use of ether is just a little prejudiced?
I'm sure this will cause some reaction, but "in my naivety" I hope I don't offend anyone?
K2


----------



## minh-thanh

Mechanicboy ,Steamchick !
  Thanks ! 

Hi Mechanicboy !


Until now, I can tell you: Maybe the way my diesel engine is built and the way it runs is different from him
Don't give his data or videos as a reference...for me.
  Don't ask me why, but please
Again, I always welcome, appreciate and thank you for your comments , of all people ,  but beyond what I just said above

This is probably my most stupid statement and I'll probably get hate for it


Mechanicboy said:


> Find Hansen diesel engine has a pump stroke at 0,03 mm under idling.
> 
> 
> Mechanicboy said:
> 
> 
> 
> Ser at this engine how to set timing..
> should be between 45 and 55 degrees before TDC.  His diesel engine is set at 45 degrees before TDC can set up to 55 degrees, but the lever with excenter at the fuel pump (see at the movie) can be adjusted 15 degrees in the area where it runs best without getting an ignition knock.
Click to expand...


----------



## lennardhme

Hi all,
         In Oz we have a great spray product called , 'Start You Bastard', mostly ether I think.
Lennard


----------



## Mechanicboy

About compression ratio, do not jump right away from 15: 1 to 20: 1, start with one step up at a time 16: 1-17: 1-18: 1 and so further to 20: 1 to find how big is the compression ratio is what you get the fuel to ignite by compression heat. So that you do not damage the engine by making a big leap direct from 15: 1 to 20: 1. Each engine construction is different when we talk about settings, compression conditions etc etc.


----------



## Mechanicboy

Steamchick said:


> Just browsing the web... as when I worked in the factory lab, my colleagues made diesel fuel for exacting test purposes by blending a base oil (Paraffin/Kerosene?) with a "10%" cocktail of napthaline stuff, and other aromatic stuff, and some lubricating oil.... I don't know the recipe but one single jar of stuff was the strong aromatic smell of DERV you get from fresh pump fuel. I noticed that some Derv I have had in the garage for a few years, no longer has the sharp aromatic smell, and I was told that the chemical was the bit that made DERV easier to ignite when injected. (I'm sure someone will know the stuff?).
> More info... https://www.chevron.com/-/media/chevron/operations/documents/diesel-fuel-tech-review.pdf
> 
> I saw a TV presentation where to use cooking oil in a diesel car, they added a cup-full (250ccs?) of "Turps substitute" to each Imperial gallon (4.5Litres) of cooking oil... "for easy starting"....
> SO knowing that road fuel has additives for "easy starting" and "home-made" alternative fuels need the same, maybe the arguement about Minh-Thahn's using a bit of Ether in the paraffin for easier running isn't such an issue?
> I would suggest that any way the the ignition is initialised by the heat of compression qualifies as a "diesel" combustion - defined by the combustion cycle determined by Rudolf Diesel I.E.
> 
> 
> https://www.mechanicalbooster.com/wp-content/uploads/2017/10/Dieselcycleworkingprocess-e1591892297266.png?ezimgfmt=ng:webp/ngcb20
> 
> 
> 
> Should this be assisted by a "hot-zone" in the engine caused by a hot glow-plug (even when not electrified) or by a "special zone" in the combustion chamber (such as the Ricardo pre-combustion injection chamber?) it still qualifies as "a diesel" as without the major heating of the gas by compression, the ignition of the fuel-air mix cannot be created.
> Considering that "Diesels" (compression ignition engines) run on everything from Ether-paraffin mixes (as for model aircraft - without glow-plugs) through to heavy oils that need steam/electrical pre-heating in order to flow in the pipework and injectors (as used on large ships), then maybe a comment about the use of ether is just a little prejudiced?
> I'm sure this will cause some reaction, but "in my naivety" I hope I don't offend anyone?
> K2



When Minh Thanh added ether in paraffin, he has increased the cetane number which makes it easier to start his diesel engine.

The cetane number
Cetane is the term that shows the ignition of the diesel, and note that most engine manufacturers require a cetane number of 50. This number is a limit value, but numbers lower than 50 give a poorer ignition of the diesel and in addition the ignition process will be disturbed. Modern engine constructions have, however, partly managed to remedy the fact that the diesel construction has not been able to follow up the development that has taken place in the area of the engine construction. Additives that increase the cetane number improve cold start properties, reduce white smoke during start-up and even reduce engine noise!

However, not all countries have access to ether due to strict laws in connection with ether being used for drug production.

Ether is not cheap to obtain and costs a portion per quantity. Paraffin is the cheapest and is more liquid than diesel oil that it atomizes more easily in the smallest model diesel engine with injection equipment (do not think of model diesel engine with compression screw to adjust compression ..).

In Norway, we have winter diesel to make it easier to start the cold diesel engine.
Diesel has a very high boiling point (180-360 degrees), but it is worse when it is cold. This is about something called the fog point (when the fuel starts to get foggy). This is because in the cold wax crystals begin to form. Fuel system, with filters. pipes and pumps, do not benefit from solids. The crystals are so small that they pass system filters with ease. As the temperature drops, the problems increase - until there is so much wax that a blockage occurs. This is why diesel is adapted to the seasons with summer diesel and winter diesel. Winter is therefore a challenge for diesel engines. Therefore, a larger proportion of hydrocarbon molecules are mixed with shorter carbon chains and lower fog points. In the old days, paraffin was often added to diesel, but this is no longer possible due to the paraffin's high sulfur content. Self-mixing of paraffin is strongly discouraged, as this can lead to breakdowns of high-pressure pumps and injection nozzles and damage to the particulate filter and catalyst due to the sulfur content. Flow-improving substances are also added to the diesel which prevent the wax crystals from clumping together.

In ordinary diesel, 7% biodiesel is mixed in based on rapeseed oil (winter diesel). The diesel used in construction machinery and leisure boats does not have biodiesel, because such a mixture absorbs water more easily, and it can pose a risk of bacterial growth in the fuel system. The element of biodiesel also means that the diesel "goes out of date". A diesel car should not stand still for more than half a year without a new tank filling.

Glow plugs are used to start up when the temperature becomes too low for the engine to suck ice-cold air into the cylinders and be controlled by the temperature sensor in modern cars. Common rail diesel engine has glow blug due cold weather in Norway in winter and controlled by ECU.

Richardo precamber needs high compression ratio up to 23: 1 to 25: 1 and it has glow plugs to start the engine. The injection needle has a pin outside the injector to distribute around inside the precamber. Also not practical in model engines due dimension is too small.


----------



## ajoeiam

Mechanicboy said:


> When Minh Thanh added ether in paraffin, he has increased the cetane number which makes it easier to start his diesel engine.
> 
> The cetane number
> Cetane is the term that shows the ignition of the diesel, and note that most engine manufacturers require a cetane number of 50. This number is a limit value, but numbers lower than 50 give a poorer ignition of the diesel and in addition the ignition process will be disturbed. Modern engine constructions have, however, partly managed to remedy the fact that the diesel construction has not been able to follow up the development that has taken place in the area of the engine construction. Additives that increase the cetane number improve cold start properties, reduce white smoke during start-up and even reduce engine noise!
> 
> 
> In Norway, we have winter diesel to make it easier to start the cold diesel engine.
> Diesel has a very high boiling point (180-360 degrees), but it is worse when it is cold. This is about something called the fog point (when the fuel starts to get foggy). This is because in the cold wax crystals begin to form. Fuel system, with filters. pipes and pumps, do not benefit from solids. The crystals are so small that they pass system filters with ease. As the temperature drops, the problems increase - until there is so much wax that a blockage occurs. This is why diesel is adapted to the seasons with summer diesel and winter diesel. Winter is therefore a challenge for diesel engines. Therefore, a larger proportion of hydrocarbon molecules are mixed with shorter carbon chains and lower fog points. In the old days, paraffin was often added to diesel, but this is no longer possible due to the paraffin's high sulfur content. Self-mixing of paraffin is strongly discouraged, as this can lead to breakdowns of high-pressure pumps and injection nozzles and damage to the particulate filter and catalyst due to the sulfur content. Flow-improving substances are also added to the diesel which prevent the wax crystals from clumping together.
> 
> In ordinary diesel, 7% biodiesel is mixed in based on rapeseed oil (winter diesel). The diesel used in construction machinery and leisure boats does not have biodiesel, because such a mixture absorbs water more easily, and it can pose a risk of bacterial growth in the fuel system. The element of biodiesel also means that the diesel "goes out of date". A diesel car should not stand still for more than half a year without a new tank filling.


Re: cetane number 
Can find docs for the minimum cetane number - - - - can't find any regarding the recommended range. 
There was some mention that a higher cetane number increases the flammability and the likelihood of greater explosiveness. 
My guess would be that mixing to get a very high cetane number would negatively impact the longevity of the engine - - - you would be creating pre-combustion when comparing to a standard #2 diesel. 
Biodiesel also increases the likelihood of bacterial contamination. The recommendation that I was told was diesel shelf life is now approximately 3 months (with gasoline being maybe a month). Some fuel additives are useful - - - - most of such are snake oil. 

Dunno about Norway but in north western Canuckistan there is NO bio-diesel in winter fuels. Biodiesel (that made from canola (likely also rapeseed) that from soy oil gels at slightly higher temperature which I don't remember) gels (coagulates) at some -18 C (IIRC) and some of the biodiesel variants can gel at far warmer temperatures ( ie those made from rendered fats). So winter fuels contain NO biodiesel. Dunno about every refinery or for every area but what was available was diesel in the following (from summer to the lightest grades)
1. #2 summer diesel rated to -20 C
2. (dunno if it was still called #2) fall diesel rated to -30 C
3. winter diesel rated to -40 C
4. arctic diesel rated to -60 C

I have experienced it only a few times but have seen very long lines of semis parked idling in very cold windy weather as when they started moving the effective temperature on the tank lines was so low that gelling occurred. Usually lasted less than 24 hours but if you've ever had the joy of needing to change the fuel filters (all of them) and then bleed everything, one step at a time from lift pump to filters to injection pump (sometimes needing to do well more than one line) and ending at the injectors (again sometimes needing to do more than one line) you just really don't want to ever have to do that again. Can't remember how long it took in my worst instance but I do know that I very carefully track my fuel characteristics and make very very sure that my fuel is fit for intended use characteristic. 

I have a complete copy of the ASTM standards for all the fuels and lubricants here in my collection. There are 4 volumes in total - - - some 6" stack of office paper sized pages. These are not to hand or I would check for 'official' standards. 
No idea when fuels move from #2 to #1. 
Also don't remember the characteristics for jet fuel either. 
Remember that #5 and #6 diesel or bunker fuel seemed to me to be far closer to crude oil than anything actually refined. Thought it interesting that such needed to be heating and run through a separation system before use - - - the stuff doesn't move at 'normal' operating temperatures.


----------



## Mechanicboy

Biodiesel from vegetable oil sources have been recorded as having a cetane number range of 46 to 52, and animal-fat based biodiesels cetane numbers range from 56 to 60.  Dimethyl ether is a potential diesel fuel as it has a high cetane rating (55-60) and can be produced as a biofuel.  


Generally, diesel engines operate well with a CN from 48 to 50. Fuels with lower cetane number have longer ignition delays, requiring more time for the fuel combustion process to be completed. Hence, higher speed diesel engines operate more effectively with higher cetane number fuels.

In Europe, diesel cetane numbers were set at a minimum of 38 in 1994 and 40 in 2000. The current standard for diesel sold in European Union, Iceland, Norway and Switzerland is set in EN 590, with a minimum cetane index of 46 and a minimum cetane number of 51. Premium diesel fuel can have a cetane number as high as 60.

In Finland, premium diesel fuels sold by Filling station chains St1 (Diesel Plus), Shell (containing GTL) and ABC (Smart Diesel) have a minimum cetane number of 60 with the typical value being at 63. Neste MY Renewable Diesel sold in Finland has a minimum cetane number of 70.

Winter diesel..

Norway has adopted the European standard into its national NS-EN 590 standard. In the mid winter period the standard diesel fuel must meet the arctic winter diesel class 2 conditions (Vinterdiesel Arktisk Grad 2).  The time frames may be extended in some regions by about ±14 days.

For the "arctic" climatic zones, the EN 590 standard defines five classes from 0 to 4. In Scandinavian countries, the winter diesel (_Vinterdiesel_) must meet Class 2 conditions. Some refiners offer both standard winter diesel and arctic winter diesel in parallel, commonly differentiated as Winter Diesel (Winterdiesel, diesel d'hiver) and Arctic Diesel (Polardiesel, diesel polaires). The low cloud point (CP) of EN 590 ensures that wax particles do not precipitate to the bottom of the tank upon standing because daytime temperatures might melt them together. Properties beyond Class 4 would require a kerosene type fuel with a low cetane number (at least 45 in EN 590). 

Biodiesel fuels are unsuitable for use in colder regions because they have a higher measure of saturated fatty acid methyl esters. To be utilized in low-temperature conditions, the biodiesel fuels should have both lower CFPP values and less saturated fatty acid content


----------



## Steamchick

minh-thanh said:


> I was thinking about this too .
> Do you know how much more effective it can be ?


Try this? - or research the "Ricardo Comet pre-combustion chamber".








						Inside the Cylinder of a Diesel Engine – by Harry Ricardo
					

Sir Harry Ricardo was one of the foremost engine designers and researchers of the internal combustion engine. In this article, he takes us through the first moments of combustion in a diesel engine…




					oldmachinepress.com
				











						Combustion Chamber: 5 Important Combustion Chambers You Must Know
					

The combustion chamber of diesel engines makes a huge impact on the performance. Here you will get the details about 5 important types of...




					engihub.com
				




K2


----------



## bluejets

Thommo said:


> For example kero is quite expensive over here in Australia as it’s only available in 1 or 2 litre bottles. It used to be available at the bowser in service stations years ago but it’s not used all that much here anymore.


1 litre Bunnings ...$4.60

20 litre drums available at any fuel depot such as BP. (around $70)

Some tractors still run on kero and I wouldn't be surprised to see 44 gallon drums at the same depots.


----------



## moose4621

bluejets said:


> 1 litre Bunnings ...$4.60
> 
> 20 litre drums available at any fuel depot such as BP. (around $70)
> 
> Some tractors still run on kero and I wouldn't be surprised to see 44 gallon drums at the same depots.



Jet A1 at your local aerodrome.


----------



## Steamchick

bluejets said:


> 1 litre Bunnings ...$4.60
> 
> 20 litre drums available at any fuel depot such as BP. (around $70)
> 
> Some tractors still run on kero and I wouldn't be surprised to see 44 gallon drums at the same depots.


I bought 4 litres for £7 at my local camping shop... (It is used in old designs of cooking stoves and blow-lamps.) - I use it as a cleaning fluid, and as fuel for my paraffin blow-lamps for silver soldering boilers. - as many as 3 for general furnace heating,. than a propane lamp for the actual joint raised to a higher temp for soldering. - The Propane costs £35 for 7kg (~10l).
Road diesel fuel is £1.42 per litre for comparison: Paraffin leaves a dry metal surface (EG. for painting) when used for surface cleaning. Road diesel fuel leaves an oiled surface - which doesn't rust so quickly - but doesn't accept paint.

K2


----------



## Steamchick

More Ricardo combustion chamber original designs.
He developed better combustion chambers to reduce knock:


			http://www-g.eng.cam.ac.uk/125/achievements/ricardo/images/th-R30.jpg
		

And swirl chambers to increase power and good combustion:


			http://www-g.eng.cam.ac.uk/125/achievements/ricardo/images/th-R33.jpg
		


enjoy.
K2


----------



## minh-thanh

Hi All !
An update:
I have conquered a real challenge : Diesel engine 10 cc .













*Thanks everyone !*


----------



## Steamchick

Minh Thanh: A brilliant conclusion. Just needs a generator and lamp to use all that power...!
When will you publish final plans?
I'd like to also express my thanks as I have learned a lot about diesel engines from the input from many experts.
K2


----------



## GreenTwin

Very nice !!!

.


----------



## ShopShoe

minh-thanh,

Congratulations on getting this engine completed and running. I have been following along and I wasn't sure how it would turn out.

Your skills are getting up with the top buiilders now.

I appreciate your sticking with this project and bringing it to this point.

--ShopShoe


----------



## minh-thanh

Thanks All !
About the plan:
  Give me little time
  With a lot of trial and error, change - change, adjust and ..... adjust... valve, injector, pump..and make new pistons, rings and cylinder heads
  With a lot of test runs I have to check if pump and injector are good enough for long run time.. and I think it is enough for my requirements.

   So much so , yesterday , there was an adjustment where the engine runs at its best and I no longer have the patience to adjust the engine again .
 The video above is not the best way to run the engine but I think it's okay for you to watch
This engine seems to take all my patience !
  I will try to finish it soon


----------



## Mechanicboy

minh-thanh said:


> Thanks All !
> About the plan:
> Give me little time
> With a lot of trial and error, change - change, adjust and ..... adjust... valve, injector, pump..and make new pistons, rings



Add piston oil ring to keep oil in the crankcase since we are spotted your engine is spitting the oil out of exhaust pipe and too much smoke. Maybe you can smell there is unburned oil smoke. It's not good for the engine. The main function of the oil ring is to scrape any excess oil from the walls of the cylinder liner when the piston is in motion. The majority of the wiped oil is directed into the crankcase back to the oil sump.


----------



## minh-thanh

Please review my previous 2 videos
And I said the last video is not the one where the engine runs the best !
You said : " WE " ??


----------



## djswain1

minh-thanh said:


> Hi All !
> An update:
> I have conquered a real challenge : Diesel engine 10 cc .View attachment 131273
> View attachment 131274
> View attachment 131275
> 
> 
> 
> 
> 
> *Thanks everyone !*



Excellent work Minh-Thanh


----------



## Thommo

minh-thanh said:


> Thanks All !
> About the plan:
> Give me little time
> With a lot of trial and error, change - change, adjust and ..... adjust... valve, injector, pump..and make new pistons, rings and cylinder heads
> With a lot of test runs I have to check if pump and injector are good enough for long run time.. and I think it is enough for my requirements.
> 
> So much so , yesterday , there was an adjustment where the engine runs at its best and I no longer have the patience to adjust the engine again .
> The video above is not the best way to run the engine but I think it's okay for you to watch
> This engine seems to take all my patience !
> I will try to finish it soon




Hey Than, I’m impressed with that little diesel! You showed a lot of courage and confidence building. Not may guys, even very experienced builders are willing to tackle a diesel. Well done!


----------



## kuhncw

Very well done, Minh Thanh.  Your engine looks very nice and runs well.  A diesel is a real accomplishment.

Chuck


----------



## minh-thanh

Hi All !
 A update :
I just redrawn my diesel engine
I will check the plan again, hope everything is ok
 Hopefully in a few days there will be drawing .


----------



## minh-thanh

Hi All ! 


Mechanicboy said:


> Ser at this engine how to set timing..
> Sorry I wrote wrong about 40-45 degrees before TDC at Find Hansen's engine, should be between 45 and 55 degrees before TDC.  His diesel engine is set at 45 degrees before TDC can set up to 55 degrees, but the lever with excenter at the fuel pump (see at the movie) can be adjusted 15 degrees in the area where it runs best without getting an ignition knock.  So you have to try out how big the angle is before TDC it goes best and easy to start up without ether in fuel and heating of the cylinder head.





* I forgot one important thing :*
When I change the compression ratio (higher) and change  fuel (using kerosene), I have to set the injection start to about 45 (maybe more) before TDC.
 I'm wrong 
* I owe Find Hansen and Mechanicboy an apology !
I'm sorry*


----------



## Mechanicboy

minh-thanh said:


> Hi All !
> 
> 
> 
> * I forgot one important thing :*
> When I change the compression ratio (higher) and change  fuel (using kerosene), I have to set the injection start to about 45 (maybe more) before TDC.
> I'm wrong
> * I owe Find Hansen and Mechanicboy an apology !
> I'm sorry*



Minh-Thanh..
You are forgiven.  

From the time atomized paraffin leaves the injection nozzle until the paraffin begins to burn is called ignition lagg.  This is why we set the injection time much earlier so that it takes time to heat up the atomized paraffin from heat of compression  until it starts to burn a few degrees before TDC.  Temperature development in a small diesel engine is not as great as large diesel engines that can have compression temperatures up to 550-600 degrees and then the injection timing will be much shorter around 10-20 degrees before TDC depending on engine design. Ignition lagg is shorter than in the model diesel engine due higher compression temperature in large diesel engine.


----------



## minh-thanh

Mechanicboy !


minh-thanh said:


> When I change the compression ratio (higher) and change  fuel (using kerosene)



Like I said, it only happens when I increase the compression ratio and use kerosene
  With less compression ratio, I set the injection time to about 20 degrees before TDC, using a mixture of ether + kerosene + oil w and using only kerosene


----------



## minh-thanh

Hi All !
Sorry for replying so late
I have to do some work and edit the plan
  Now the plan is done
Price: 30 usd
Paypal account: [email protected]
I'm not a professional engine designer, let me know if I'm missing something or  something you don't understand 
   If you have any questions, please email: [email protected]


----------



## awake

minh-thanh said:


> Hi All !
> Sorry for replying so late
> I have to do some work and edit the plan
> Now the plan is done
> Price: 30 usd
> Paypal account: [email protected]
> I'm not a professional engine designer, let me know if I'm missing something or  something you don't understand
> If you have any questions, please email: [email protected]



Paypal sent, including email address. Looking forward to seeing the plans!


----------



## awake

I received the plans promptly, and they look good! I am looking forward to digging into them in detail. Thanak, Minh-Thanh!


----------



## minh-thanh

Hi Awake !
Thank You very much !
Let's make a diesel engine. And when you make it run you will have many surprises , *I SURE* !
  And then, it's not just one or two people who can do it
 And then there will be more diesel engines and more designs....


----------



## Chaffe

Hello, great write up. Do you have any techniques for machining injection pump bore? Also injection pump piston itself? Some sort of lapping perhaps? What sort of tolerances are acceptable here? 
I have a similar project in progress but currently use tiny nitrile O rings for seals, not ideal.


----------



## Chaffe

It has been an ongoing project for a couple years, with many interruptions


----------



## Chaffe

Here in action with 100% kerosene, injection pressure is very low at 8 bar, this is something I am working on


----------



## minh-thanh

Hi Chaffe !

With me : drill - reamer - lapping
Small hole lapping tool : you can buy it or make it yourself - I made it myself









						McMaster-Carr
					

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.




					www.mcmaster.com
				




  Lapping pump cylinders is challenging and very patient
  All scratches caused by drilling or reaming must be removed
Tolerance : I think it's about 0.01 -> 0.02 mm - I'm not sure - Because it's too small
  I used o - ring - just for testing . They fail quickly with high pressure .This only improves when the cylinder surface is very smooth. I don't know if it will last long, but I don't like it to  fail when I'm testing as well as I want the engine to run for a long time.
   Piston: I make the piston diameter 0.1 - > 0.3 mm larger than the cylinder (this depends on the surface when machined), then lapping the piston until the piston slides into the cylinder with w20 oil
 Cylinder and piston surfaces must be smooth


----------



## Chaffe

Thanks, my next plan was exactly as you describe, using cast iron for cylinder and silver steel as piston, a split aluminium lap. 
but first I must finish my Stuart steam engine…


----------



## minh-thanh

I also use brass for the cylinder , they're pretty good


----------



## Mechanicboy

minh-thanh said:


> Hi Chaffe !
> 
> With me : drill - reamer - lapping
> Small hole lapping tool : you can buy it or make it yourself - I made it myself
> 
> 
> 
> 
> 
> 
> 
> 
> 
> McMaster-Carr
> 
> 
> McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
> 
> 
> 
> 
> www.mcmaster.com
> 
> 
> 
> 
> 
> Lapping pump cylinders is challenging and very patient
> 
> Tolerance : I think it's about 0.01 -> 0.02 mm - I'm not sure - Because it's too small
> I used o - ring - just for testing . They fail quickly with high pressure.



The tolerance must be tight to prevent leakage in the fuel pump and still move free. Tolerance is 0.001 mm. Steel piston in cast iron cylinder. First lap the cylinder to final blank as mirror and lap the piston blank as mirror. Then adapt the piston into the cylinder carefully with oil and test the piston is moving free without leakage into the cylinder.


----------



## minh-thanh

It is possible,  if you are able to make 0.001 mm tolerance, as well as cylinder and piston should be 100% straight
it's impossible for me 

" Mirror surface " : I'm not sure
    The surface that looks like the picture is fine:


----------



## minh-thanh

Chaffe said:


> Here in action with 100% kerosene, injection pressure is very low at 8 bar, this is something I am working on


 Your injector  are pretty good !!


----------



## Mechanicboy

minh-thanh said:


> It is possible,  if you are able to make 0.001 mm tolerance, as well as cylinder and piston should be 100% straight
> it's impossible for me
> 
> " Mirror surface " : I'm not sure
> The surface that looks like the picture is fine:View attachment 132676



Surface in cylinder is good. 

In fact not impossible to make straight cylinder and piston. I did with the Wakefield lubricator for steam engine without O-ring.

To keep tight without gasket or O-ring: make piston long as possible in relation to diameter so that there are smaller leaks past the piston and cylinder.  Round off the end of the piston so that it fits more easily into the cylinder during installation and avoid accidental scratches.  Use finer abrasive, eg polishing paste, to fit the piston into the cylinder with the utmost care.  If the piston has entered the cylinder, clean properly and lubricate and take a leak test that it is without leakage of fuel.


----------



## Chaffe

Thanks guys, I have finished my steam engine project, now I have spent some time on my new injector pump. Cast iron body with steel piston, still need to refine the piston as it has some leakage, but looking promising.
I have a question, my delivery check valve doesn’t seal (ball and spring type) how are we all making successful check valves? This one is flat sealing face with seat hole size 75% of ball diameter. My next design was going to be with a 30 taper (60 degree inclusive, ie centre drill) I feel the ball is not being driven in hard enough or on centre currently. 
interested to hear how others have succeeded


----------



## Richard Hed

Chaffe said:


> Thanks guys, I have finished my steam engine project, now I have spent some time on my new injector pump. Cast iron body with steel piston, still need to refine the piston as it has some leakage, but looking promising.
> I have a question, my delivery check valve doesn’t seal (ball and spring type) how are we all making successful check valves? This one is flat sealing face with seat hole size 75% of ball diameter. My next design was going to be with a 30 taper (60 degree inclusive, ie centre drill) I feel the ball is not being driven in hard enough or on centre currently.
> interested to hear how others have succeeded


Do you have any photos of your engine?  Have you polished the check valve?  I would certainly thimpfk an angled valve would be better.


----------



## Chaffe

Richard Hed said:


> Do you have any photos of your engine?  Have you polished the check valve?  I would certainly thimpfk an angled valve would be better.


Only the photos I posted a few posts ago. 
I am treating the engine and injection system as two separate things. I think the engine it’s self will be an easy task.


----------



## Chaffe




----------



## Chaffe

The brass fitting above is in fact my delivery check valve, it’s m5/m6 so you can appreciate the size. The ball is 2mm and is some 11mm deep to the seat, there is also a spring and retaining collar inside. I am not sure how you would polish such a seat so deep?


----------



## ajoeiam

Chaffe said:


> The brass fitting above is in fact my delivery check valve, it’s m5/m6 so you can appreciate the size. The ball is 2mm and is some 11mm deep to the seat, there is also a spring and retaining collar inside. I am not sure how you would polish such a seat so deep?



My first response was going to be - - - carefully - - - but then that's being a turkey!
Some emery on a stick - - - - some scotchbrite (there are ever so many grades of this stuff!) on a stick. 

I've never seen it but molds for CDs/DVDs etc are polished to an incredibly high level so a high polish 'is' possible.


----------



## Chaffe

You’ll not get emery or scotchbrite in a 2mm hole, 11mm deep….
ideally I would want to polish it with a ball soldered onto a brass rod, with compound. I believe the new design with a 30 degree seat and slightly larger ball will be better.


----------



## minh-thanh

Chaffe said:


> You’ll not get emery or scotchbrite in a 2mm hole, 11mm deep….
> ideally I would want to polish it with a ball soldered onto a brass rod, with compound. I believe the new design with a 30 degree seat and slightly larger ball will be better.


Make a lapping tool by aluminum with diameter 2mm , first with grit 400 , 600 after : 1800 , 2000
then use a small hammer to lightly tap the ball to make a valve seat


----------



## Chaffe

minh-thanh said:


> Make a lapping tool by aluminum with diameter 2mm , first with grit 400 , 600 after : 1800 , 2000
> then use a small hammer to lightly tap the ball to make a valve seat


Hi, I have what I consider to be quite a good bore (size and finish) in my cast iron pump, the piston was in fact not machined and I tried to use ground stainless bar, it is too small… I’ll make a piston when time permits.
The check valves seem to be the real test for me  I will try a tapered seat instead of the usual flat bottom seat, I think the spring is pushing the ball off centre slightly


----------



## minh-thanh

Chaffe said:


> The check valves seem to be the real test for me  I will try a tapered seat instead of the usual flat bottom seat, I think the spring is pushing the ball off centre slightly


Hi !
Flat seat or tapered seat : they are the same when in contact with the sphere - balls
  Make the valve seat surface like polishing, and the way i do it will be fine .


----------



## minh-thanh

Chaffe !


Chaffe said:


> Hi, I have what I consider to be quite a good bore (size and finish) in my cast iron pump, the piston was in fact not machined and I tried to use ground stainless bar, it is too small… I’ll make a piston when time permits.
> The check valves seem to be the real test for me  I will try a tapered seat instead of the usual flat bottom seat, I think the spring is pushing the ball off centre slightly


 
_Real test_ : Including me, I had to redo it at least a few times before it was really tight
  I have tried both the flat seat and the taper seat, and they are ok. Important is the valve seat surface,* it must be Perfect*. Use a magnifying glass when you look at the valve seat surface
   Cylinder - piston : Make the piston until it can only slide into the cylinder with a little oil w20
*  Remember: We are working with a very small amount of fuel and must have high pressure*


----------



## Thommo

Hey Than, it seems that you are rapidly becoming the miniature Diesel engine guru!! Good on ya.


----------



## minh-thanh

Hi mate !
"guru" or "expert" : I'm not
    I'm not sure if what I said is true 
  Just hope it provides some information ...


----------



## Gedeon Spilett

Hi Minh Thanh
great achievement with your engine, thanks for the plan...
as a good compression ignition engine may have volumetric ratio near 1:19 and above, how come we need to add ether to get combustion ? any clue ? 
I'm a novice in the theory of the diesel cycle may I add...


----------



## Chaffe

Gedeon Spilett said:


> Hi Minh Thanh
> great achievement with your engine, thanks for the plan...
> as a good compression ignition engine may have volumetric ratio near 1:19 and above, how come we need to add ether to get combustion ? any clue ?
> I'm a novice in the theory of the diesel cycle may I add...


Simple answer is heat, heat is lost to the cylinder walls, piston, head and the fuel. The smaller the cylinder the less heat energy you will get from the air charge. Physics don’t scale very well, especially when it comes to thermal dynamics.


----------



## minh-thanh

Hi Gedeon Spilett !
Thank you very much !


Gedeon Spilett said:


> as a good compression ignition engine may have volumetric ratio near 1:19 and above, how come we need to add ether to get combustion ? any clue ?
> I'm a novice in the theory of the diesel cycle may I add...


 
With high compression ratio can be from 18 -1 or higher without adding ether to the fuel.
  The theory of the diesel cycle: when I made this engine I didn't pay much attention to that theory. I just need an engine with a high compression ratio - somewhere around 16 -1 , If the engine can run with an ether mixture I would increase the compression ratio to 18 - 1 or higher
  When I was a student, I could spend hours thinking and solving a difficult problem of physics, math... Now I'm very lazy.


*Chaffe !*



Chaffe said:


> Simple answer is heat, heat is lost to the cylinder walls, piston, head and the fuel. The smaller the cylinder the less heat energy you will get from the air charge. Physics don’t scale very well, especially when it comes to thermal dynamics.


  Thank you !!


----------



## Mechanicboy

Chaffe said:


> Simple answer is heat, heat is lost to the cylinder walls, piston, head and the fuel. The smaller the cylinder the less heat energy you will get from the air charge. Physics don’t scale very well, especially when it comes to thermal dynamics.



In a model diesel engine with carburator from 0,1 ccm who are smallest and larger is simplere to atomize the fuel in smaller fuel drops and mix into the air before entering in the cylinder and the fuel mix is allready gaseous heated by engine before compression is started to heat up the air. Also the small injector is more difficult to atomize so finer and smaller drops to heat up so quickly to form as gaseous fuel in the small engine who has large heat of loss in surfaces.


----------



## Gedeon Spilett

Thanks for the answer, Chaffe, the loss in heat in a tiny engine makes sens for me, although I read somewhere in this very informative thead that the compression is adiabatic !


----------



## ajoeiam

Mechanicboy said:


> In a model diesel engine with carburator from 0,1 ccm who are smallest and larger is simplere to atomize the fuel in smaller fuel drops and mix into the air before entering in the cylinder and the fuel mix is allready gaseous heated by engine before compression is started to heat up the air. Also the small injector is more difficult to atomize so finer and smaller drops to heat up so quickly to form as gaseous fuel in the small engine who has large heat of loss in surfaces.



Hmmmmmmmm - - - sorry friend - - - I don't think your going to be using a carburetor in a diesel (compression ignition) engine. 
Just doesn't work that way. 
Possibly you were referring to an injection pump but that's not really a carburetor.


----------



## Mechanicboy

ajoeiam said:


> Hmmmmmmmm - - - sorry friend - - - I don't think your going to be using a carburetor in a diesel (compression ignition) engine.
> Just doesn't work that way.
> Possibly you were referring to an injection pump but that's not really a carburetor.



Are you sure model diesel engine doesn't to have the carburettor?

Read this link . Carbureted compression ignition model engine - Wikipedia

And here is the old Norwegian chain saw with carburettor and hot bulb.


----------



## ajoeiam

Mechanicboy said:


> Are you sure model diesel engine doesn't to have the carburettor?
> 
> Read this link . Carbureted compression ignition model engine - Wikipedia
> 
> And here is the old Norwegian chain saw with carburettor and hot bulb.





Well - - - in reading your attached url - - - it does say - - - - 'no relationship 
with actual diesel engines' . 

I've run into a lot of different kinds of engines but never a high compression 
otto cycle engine with hot bulbs. 

Wonder why they would even want to make an engine like that chain saw 
with the hot bulb. Maybe so that kerosene could be used. 

Know that in extreme cold temperatures the 'gasoline' formulation is modified 
so that everything works well. 

I will - - - still - - - maintain that a real compression ignition engine does NOT use a carburetor. 
(Notwithstanding certain anomalous variants!!)


----------



## Mechanicboy

ajoeiam said:


> I will - - - still - - - maintain that a real compression ignition engine does NOT use a carburetor.
> (Notwithstanding certain anomalous variants!!)




Carburetor or injection is not important.  They have one thing in common: Develop heat by compression to ignite fuel.


----------



## minh-thanh

Mechanicboy said:


> Carburetor or injection is not important.  They have one thing in common: Develop heat by compression to ignite fuel.


 Let's focus on one type of injector diesel engine.!!


----------



## Mechanicboy

minh-thanh said:


> Let's focus on one type of injector diesel engine.!!



Minh-Thanh..
Calm down, there is no reason for you to be aggressive in the forum.


----------



## awake

That was aggressive? Seemed more like a desire to stay on topic for the thread.

In terms of fuel used, I think Minh said it would run on ether one.


----------



## Donrecardo

ajoeiam said: 


           Hmmmmmmmm - - - sorry friend - - - I don't think your going to be using a carburetor in a diesel (compression ignition) engine.
Just doesn't work that way.

This one does


----------



## methuselah1

I am new to this thread, so I'm probably only repeating what someone else will have already written. True diesel engines inject fuel into a compressed charge of air. Compression ignition engines use a very different fuel, and rely on compression to ignite a ready mixed charge instead. Hence the carburetter.

Misnomer as it is, aeromodellers always refer to this type as "diesel", even if that's incorrect; but when one AM speaks engines to another AM, they both know _exactly_ what they're talking about. Paraffin burning motors, lubricated with castor oil, ignited by diethyl ether.

At the most basic level, these constituents are mixed 1:1:1, sometimes with a little amyl nitrate as a dope.

-Andrew UK


----------



## ajoeiam

Donrecardo said:


> ajoeiam said:
> 
> 
> Hmmmmmmmm - - - sorry friend - - - I don't think your going to be using a carburetor in a diesel (compression ignition) engine.
> Just doesn't work that way.
> 
> This one does



Hmmmmmmm - - - developed my thinking when this:







was a 'small' engine. 

This was the workhorse: 





						TractorData.com Massey-Harris 44 tractor information
					






					www.tractordata.com
				









(that one is looking a little under the weather) 

and this one was parked (I played on it and made it go real hard but carefully - - - I had been warned that when it pulled very hard that it might start running backwards - - - so careful was the game - - LOL (this one pictured is is FAR better condition than the one we had)) 







this: 






is a BIG engine (buts its a diesel - - - compression ignition - - - engine)





Your engine - - - it may be 'called' a diesel engine but for me - - - sorry a compression ignition engine that requires ether on a constant basis - - - 
that's stretching the envelope just a bit too far. 

It has been very interesting following the trials of getting an injection system working. 

I'm following because the information might be usable in designing something like a 5 kW medium or maybe even a touch slower 'diesel' engine for power generation purposes.


----------



## Donrecardo

You wrote 

Misnomer as it is, aeromodellers always refer to this type as "diesel", even if that's incorrect;

*Diesel engine - Wikipedia*


https://en.wikipedia.org › wiki › Diesel_engine
The *diesel* *engine*, named after Rudolf *Diesel*, *is* an internal combustion *engine* in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression;

So what aeromodellers call it  is not incorrect.  regardless of what fuel it uses , as long as it ignites due to compression its a diesel 

the picture above is of an engine that relies on compression to elevate the temperature till it ignites* and *it does have a carburetta


----------



## ajoeiam

Donrecardo said:


> You wrote
> 
> Misnomer as it is, aeromodellers always refer to this type as "diesel", even if that's incorrect;
> 
> snip
> the picture above is of an engine that relies on compression to elevate the temperature till it ignites* and *it does have a carburetta



I didn't coin the first phrase. 
Searching wikipedia research it is not. 
We'll agree to disagree then - - - yes?

Maybe we should be striving to create the new improved wonderful version of the best electric motor. 
Society - - - or at least some parts of it are hell bent on eliminating internal combustion engines - - - of any type!


----------



## Mechanicboy

Many people think that it is the injection that causes the engine to be called "diesel engine".  No one clearly thinks that it is the compression heat itself that is the main source of igniting the fuel whether the engine has injection or carburetor.  We also find the same in petrol engines that have direct injection (GDI), injection or carburetor, what distinguishes them from diesel engines is that an electric spark is used to ignite the fuel as the compression heat is not high enough to ignite the fuel.  In the whole word, we separate the motors in 2 ways: Ignite by compression or ignite with electric spark.  Not how we supply the fuel into the combustion chamber either it's a diesel engine or petrol engine.


----------



## Donrecardo

Mechanicboy said:


> Many people think that it is the injection that causes the engine to be called "diesel engine".  No one clearly thinks that it is the compression heat itself that is the main source of igniting the fuel whether the engine has injection or carburetor.  We also find the same in petrol engines that have direct injection (GDI), injection or carburetor, what distinguishes them from diesel engines is that an electric spark is used to ignite the fuel as the compression heat is not high enough to ignite the fuel.  In the whole word, we separate the motors in 2 ways: Ignite by compression or ignite with electric spark.  Not how we supply the fuel into the combustion chamber either it's a diesel engine or petrol engine.



Exactly , and as the aero engine picture shows it relies on compression for ignition not injection which is why it can use a carburetta


----------



## minh-thanh

Mechanicboy.
I was reading another thread in this forum and elsewhere, and there was a debate about diesel, real diesel, compression-ignition, fuel injection or carburetor.... ,.. .. It's a problem that I don't want to happen again
 So I want:


minh-thanh said:


> Let's focus on one type of injector diesel engine.!!


   And now that you've got what you wanted...well done...go on .


----------



## djswain1

Minh-thanh started the thread, then designed and built his own diesel engine. No small achievement.... So on this this thread I think what he says goes and we keep this thread to fuel injected CI "diesel" engines.
Perhaps a new thread could be started for a more general discussion on compression ignition or diesel engines in all their various forms.
Cheers, Dave.


----------



## Chaffe

Some success with the “old” style injection pump, Minh-Thanh what injection pressure does your injection pump achieve? What pressure are you popping your injector at? Chaffe


----------



## minh-thanh

Hi Chaffe !
One question I can only answer: I don't have any pressure readings at the moment
  Sorry !!
I will buy a pressure gauge and will check
  When I made this diesel engine, the Covid epidemic situation increased, so my place was completely  lockdown, I could only test the injectors and pump with the engine., I could only trial and error and do everything the best thing possible.
  Until the epidemic situation showed signs of abating, I could only buy back a small copper pipe from a friend that he had left over,  but I still couldn't buy a pressure gauge., again I can only test the injectors and pump with the my engine and based on my experience and judgment
Trial and error, adjust...... until the engine feels like it can "run"., and trial and error, adjust..... until the engine run
I can't watch your video


----------



## Chaffe

minh-thanh said:


> Hi Chaffe !
> One question I can only answer: I don't have any pressure readings at the moment
> Sorry !!
> I will buy a pressure gauge and will check
> When I made this diesel engine, the Covid epidemic situation increased, so my place was completely  lockdown, I could only test the injectors and pump with the engine., I could only trial and error and do everything the best thing possible.
> Until the epidemic situation showed signs of abating, I could only buy back a small copper pipe from a friend that he had left over,  but I still couldn't buy a pressure gauge., again I can only test the injectors and pump with the my engine and based on my experience and judgment
> Trial and error, adjust...... until the engine feels like it can "run"., and trial and error, adjust..... until the engine run
> I can't watch your video











						Injection pressure test
					






					youtube.com


----------



## Chaffe

I have done some maths and I think 40 bar injection pressure will work with 45 degrees injection timing. Cylinder pressure at that point will not be high. The injector should withstand 650bar cylinder pressure with that spring too, assume 8kg spring and the size nozzle I am running.


----------



## minh-thanh

Your pump produces pretty good pressure !
 Do you have oil leaks between the cylinder and piston or in the joints ?
I plan to buy a pressure gauge to measure the pressure in the cylinder and also the pump
Do you have any suggestions for pressure gauges ?


----------



## Chaffe

minh-thanh said:


> Your pump produces pretty good pressure !
> I plan to buy a pressure gauge to measure the pressure in the cylinder and also the pump
> Do you have any suggestions for pressure gauges ?


Thanks, I think it will be adequate, I will now continue work on my engine and try complete the project in 2022….
As for gauges this was surplus’s from a job at work, but something off eBay would do? I don’t think you will need one above 100 bar… but you never know!


----------



## minh-thanh

Thank you !
Do you have oil leaks between the cylinder and piston or in the joints ?


----------



## Chaffe

minh-thanh said:


> Thank you !
> Do you have oil leaks between the cylinder and piston or in the joints ?


No leaks at all so far, the screwed connections were surprisingly easy to make successfully. It will hold 40 bar (500psi) for several seconds too, which is promising.
I will focus my efforts on a 40 bar injector and then the engine itself now.


----------



## minh-thanh

Looks like you're one step closer to building an diesel engine of your own
  Please update when there's something new !


----------



## Chaffe

minh-thanh said:


> Looks like you're one step closer to building an diesel engine of your own
> Please update when there's something new !


I will do, I don’t have the time or inclination for a full thread, but will certainly highlight any new breakthroughs.


----------



## minh-thanh

Chaffe said:


> I will do, I don’t have the time or inclination for a full thread, but will certainly highlight any new breakthroughs.


And :
If your engine is nicer and runs better than mine, I'll hate you


----------



## Chaffe

minh-thanh said:


> And :
> If your engine is nicer and runs better than mine, I'll hate you


If it runs I’ll be delighted


----------



## Bentwings

You may have to get automotive gages I’ve been looking for model steam gages for some time too. I might just be too picky in what I want and need. Automotive gage prices have gone up dramatically in price just in the last year. I don’t know what small engines might require . I know my one ton dusky Cummins has pretty high around 2500 psi. The lift pump I only about 10-15 but that is just supply to the high pressure pump. . I have not dealt with model diese excep early model airplane ones Davis diesels they did not use high pressure pump just enter based fuel they had adjustable compression so they did operate as “real” diesel or compression ignition. 
byron


----------



## Chaffe

A gauge is a gauge, as long as the range is correct it will work fine.


----------



## Gedeon Spilett

Looking at the plan of your diesel engine, I wonder why the ratio stroke/bore reaches 2, is it for simple geometric reason to get high compression ratio or a thermal explanation underlies this choice? I know that many very old diesel  had also a similar ratio, and other early engine too !
I'm not yet ready to the challenge of building one, i'm afraid to loose motivation during the test of the injector and pump, I'not a young man.


----------



## minh-thanh

Hi Gedeon !


Gedeon Spilett said:


> Looking at the plan of your diesel engine, I wonder why the ratio stroke/bore reaches 2, is it for simple geometric reason to get high compression ratio or a thermal explanation underlies this choice? I know that many very old diesel  had also a similar ratio, and other early engine too !


 
Simply: High compression ratio and including heat
  The higher the compression ratio, the higher the air is compressed and more heat is generated due to the compression
  And....I plan to make some engines that I like in that ratio



Gedeon Spilett said:


> I'm not yet ready to the challenge of building one, i'm afraid to loose motivation during the test of the injector and pump, I'not a young man.


 
Young or old doesn't matter  !!
   Do think of making a diesel engine as a "game" and you are playing with it
  Don't try to think it's too complicated or too difficult....
 Although I succeeded, but if I make the new injector and pump: I will definitely have to redo a few times to get the injector or pump good enough.
  Please be patient !!!


----------



## gg89220

Gedeon Spilett said:


> I'm not yet ready to the challenge of building one, i'm afraid to loose motivation during the test of the injector and pump, I'not a young man.


vas y Gedeon,lance toi !!


----------



## Gedeon Spilett

Thanks Minh-Thanh for the answer, I 've got it.
It also has to do with the low rpm that diesel engines have. 


hi gégé, I don't want to break your priority, buddy ! go head 
actually I think I'm chickening out...


----------



## krakkah

ajoeiam said:


> Well - - - in reading your attached url - - - it does say - - - - 'no relationship
> with actual diesel engines' .
> 
> I've run into a lot of different kinds of engines but never a high compression
> otto cycle engine with hot bulbs.
> 
> Wonder why they would even want to make an engine like that chain saw
> with the hot bulb. Maybe so that kerosene could be used.
> 
> Know that in extreme cold temperatures the 'gasoline' formulation is modified
> so that everything works well.
> 
> I will - - - still - - - maintain that a real compression ignition engine does NOT use a carburetor.
> (Notwithstanding certain anomalous variants!!)


If you know any history behind how typical diesel injection came about, youll know Rudolph Diesel himself almost killed himself using a carburettor style fuel supply. Which is why he invented the injector. But for small stuff a carby works.


----------



## minh-thanh

Hi All !

Sharing some of my diesel discoveries:
*1/* Injection time: More precisely the time the lobe begins to contact the pump piston: 22 to 45 degrees before TDC
*2/* Engine runaway : Should   be worried?
 If your design calculates lobe timing, intake and exhaust ports....exactly like a full size diesel engine then you should worry. But with a small engine you can easily stop the engine.
 With many tests, my engine can not  runaway
*3/* Injection : Fuel vaporization-Atomized fuel  . How to inject fuel 
*3A/* Fuel vaporization-Atomized fuel : It is necessary but not all.
Fuel vaporization-Atomized fuel will give you an objective view of the efficiency of the pump and injectors: the pressure generated by the pump, the tightness of the injectors....and when the engine is running it will have very little smoke.
 " Not all " because when i make some test with my engine the injectors just "inject "  fuel - as in the picture (Some cases are even worse)- -and the engine is still run






 .  This leads to 2 cases: *a/* the engine runs but a lot of smoke and some unburnt fuel (it looks like mud) comes out the exhaust pipe and *b/* the engine a lot of smoke . Solve this problem: simply increase the compression force of the needle spring
*3B/*  How to inject fuel :
fuel injection : radiates from the center - good
Fuel injection is left or right: it doesn't matter 
With a full size diesel engine, the fuel vaporization-Atomized fuel, the fuel injection, ... needs to be really good because it concerns the performance ... of the engine, and that's what is really needed.
  But with a homemade diesel engine, you can stick to that rule if you want, and that's how I do it with my engine.
  If you only need one engine running then it shouldn't be too important. And the engine has running, you can easily adjust the injectors...to make the engine run better 

One important thing is : the injector must be completely sealed .
  If the injector is not completely sealed it will affect the pressure in the cylinder and the oil pressure in the oil pipe
 Hope this gives those who are or intend to build diesel a little more confident


----------



## Badhippie

One thing that has not been mentioned that I have seen in this thread. The normal diesel exhaust should I say all diesel exhaust has a very nasty chemical it produces. You can’t get rid of it but you sure in the hell can make it worse by incorrect injector timing, a dripping injector, incorrect pump to engine timing etc. 
 The chemical a Diesel engine exhaust produces is sulfur this is a by-product you of combustion process. Then you add another by-product that every engine in the world produces is moisture. Then you add moisture to sulfur and what do you have?? A great little product called sulfuric acid. This is just something for everyone to think about when building a Diesel engine. With proper maintenance of the engine it’s should never be a problem. But without proper maintenance it becomes a huge problem. I have actually seen rod caps,rod studs and other items either eroded or eaten all the way thru and cause catastrophic engine failure. Just wanted to throw that out there and let you all soak that up 
Thanks 
Tom


----------



## Steamchick

Hi Tom. I went to a presentation by Caterpillar (they make big engines and big tractors and earth moving plant that use the engines).  The guy presented a talk on use of their engines for NON- earthy applications. Eg. Generators using industrial waste as fuel. One of the worst was sewage plant gas. It was so full of sulphur that the engines were corroded (exhaust valves ports, etc.) in 1/10th of the "normal" plant useage with diesel fuel. But they also had generators burning chaff from granaries, sawdust and other dust of particulate organic hydrocarbons. Some of those were particularly toxic to engines, and needed huge exhaust gas treatment plants. He reckoned he had the highest order book for spares of any engineer! So we should be thankful that DERV is such a clean (cleverly engineered) fuel.
And did you realise the nitrous oxides made in diesels form nitric and nitrous acids? As bad as the sulphuric and sulphurous acids! Yet the planet will be destroyed (So we are taught) by Carbon dioxide, which when dissolved in water makes Carbonic acid! We are on a hiding to nothing!
Enjoy modelling!
K2


----------



## Badhippie

Yes k2 I did know this I worked on Cummins engines for 20 years then I was in charge of a locomotive engine rebuild shop and component rebuild and machine shop for about 11 years. Yes I am very well aware of what a Diesel engine produces. I think sometimes I exhaust diesel smoke I have inhaled so much over the years lol lol. People think exhaust from a gas engine will kill you and yes it is true. But diesel exhaust will eat you from the inside out lol


----------



## Chris Murphy

When you add moisture to sulphur.....all you get is damp sulphur!     There is some rather ill understood chemistry being written above-for a start you don't get sulphuric acid that way-it is formed by sulphur TRI-OXIDE reacting with water. The product you get in diesel exhaust is sulphur DI-OXIDE -not sulphur which is an element. Sulphur DI-oxide and moisture produces sulphurOUS not sulphurIC acid.     This is junior high school chemistry level stuff... !    There are all sorts of trace level components in crude oil-many of which make their way into various fuels in trace levels....how much is determined either by suppliers or government regulation-which can differ widely in different jurisdictions. As for nitrous and nitric oxides-well I guess you'd better complain to mother nature about how inconsiderate she was making the atmosphere 4/5 nitrogen.....and leaving it contaminated by 20% oxygen...

ChrisM
Bsc(Hons) PhD   (in light of the above I'll let you guess in what subject area...)


----------



## Steamchick

Thanks Chris, not being a chemist I value your input! I just know a little about a lot of things, and get notions that may be off-the mark. But, I think, the principles are there. "Nasty" chemicals are made in the engine. The curious thing about room temperature chemistry versus combustion chamber chemistry, is that in the combustion chamber there is a lot of heat, molecules become ionised, and the pressure is more than 20 times atmospheric in parts, so a lot of odd reactions occur that would not happen at STP.  e.g. NOx formation. And what happens in the spark in spark ignition engines? - Possibly Ozone formation etc.? - I really haven't a clue, but your advice will be of interest (to me at least).
I only really know that engine oils contain additives (Such as Zinc compounds) to neutralise all the various acids in the blow-by gases, that when dissolved in oil (with some H2O), form highly corrosive acids that need to be neutralised by the Zinc, etc, additives. And similarly, the move from steel to stainless steel exhausts was in part due to the _acidic _condensate accumulating in exhaust systems and causing "early life" failures. (Such failures are banned by legislation in the emissions laws - minimum 80,000km lifetime, etc. & "no leaks" clauses.).
Thanks.
 K2


----------



## ajoeiam

Badhippie said:


> One thing that has not been mentioned that I have seen in this thread. The normal diesel exhaust should I say all diesel exhaust has a very nasty chemical it produces. You can’t get rid of it but you sure in the hell can make it worse by incorrect injector timing, a dripping injector, incorrect pump to engine timing etc.
> The chemical a Diesel engine exhaust produces is sulfur this is a by-product you of combustion process. Then you add another by-product that every engine in the world produces is moisture. Then you add moisture to sulfur and what do you have?? A great little product called sulfuric acid. This is just something for everyone to think about when building a Diesel engine. With proper maintenance of the engine it’s should never be a problem. But without proper maintenance it becomes a huge problem. I have actually seen rod caps,rod studs and other items either eroded or eaten all the way thru and cause catastrophic engine failure. Just wanted to throw that out there and let you all soak that up
> Thanks
> Tom


Sorry - - - your information on sulfur in diesel is about 40 years out of date. 
Tried finding the date of introduction in North America and can't in a short search. 
Ultra-low sulfur diesel (0.05%) has been around since some time in the 90s. There was an increase in fuel additive recommendations to counter the change in the fuel formulations that were happening (one of the better additives is actually 'bio-diesel' - - - grin! see "Howe's diesel (something or other - - - cant' remember right now if its called conditioner or what)). 
Only #5 and 6 diesel - - - more commonly called bunker fuel are allowed higher rates of sulfur inclusion (higher lubricity in the fuel!!). 
If you really are that panicked by the amount of sulfur in diesel exhaust I do hope that you are mitigating your exhausts because your natural gases from the lower end contain significantly higher amounts of sulfur and even the CO and CO2 from your breathing could be considered problematic if one wants to follow the newest most paranoid thinking.


----------



## ajoeiam

Steamchick said:


> Thanks Chris, not being a chemist I value your input! I just know a little about a lot of things, and get notions that may be off-the mark. But, I think, the principles are there. "Nasty" chemicals are made in the engine. The curious thing about room temperature chemistry versus combustion chamber chemistry, is that in the combustion chamber there is a lot of heat, molecules become ionised, and the pressure is more than 20 times atmospheric in parts, so a lot of odd reactions occur that would not happen at STP.  e.g. NOx formation. And what happens in the spark in spark ignition engines? - Possibly Ozone formation etc.? - I really haven't a clue, but your advice will be of interest (to me at least).
> I only really know that engine oils contain additives (Such as Zinc compounds) to neutralise all the various acids in the blow-by gases, that when dissolved in oil (with some H2O), form highly corrosive acids that need to be neutralised by the Zinc, etc, additives. And similarly, the move from steel to stainless steel exhausts was in part due to the _acidic _condensate accumulating in exhaust systems and causing "early life" failures. (Such failures are banned by legislation in the emissions laws - minimum 80,000km lifetime, etc. & "no leaks" clauses.).
> Thanks.
> K2



I do hope that you're getting a lot more than 20x atmospheric pressure in even your gas engine. In a diesel engine it is even higher.

I wonder if there has been any measuring of the ozone caused by the use of electric motors in vehicles? 

(Seems that there has but the quantities are presently being pooh poohed. Somehow I remember a huge brouhaha not even that long ago about the depleting upper atmospheric ozone caused purportedly by those vile automobiles - - - maybe we all just need to walk - - - ie get rid of all personal transportation! - - - no horses either!)


----------



## minh-thanh

Hi!
  Are you too worried about CO, CO2, NO, NO2, acids ....generated with  diesel engine 10cc ?

Running the engine in a well-ventilated area
and the maintenance of the engine after running is something I do very carefully, so I don't worry .


----------



## Chris Murphy

The simple reality is that our engines operate at elevated temperatures and pressures-as steamchick notes above-at elevated temps and pressures all sorts of other reactions occur-including those that might not occur at room temperature and unconstrained combustion. A variety of metals are involved in our engines-some of which may well contribute to the myriad of reactions by providing a degree of unintended catalytic effect-especially with the use of some exotic metals in spark plugs, let alone the other additives we find in fuel. There will always be side reactions and trace level/trace element reactions going on under the guise of the overall combustion process-which of course is never stoichiometrically complete.....by chemistry standards...which is why we get soot and carbon monoxide emitted-in addition to all the other components.

If we can cast our minds back to the late 70s and early 80s.....the big issues THEN were acid rain and global COOLING....the former largely being a result of the extensive use of coal in industry-another fossil fuel that contains a fair amount of sulphur.....and surprise surprise, oxides of sulphur were one of the contributors to acid rain....along with the analagous various oxides of nitrogen-which also contribute-in the form of nitrous and nitric acids.

We tend to conveniently overlook the other nasties like cadmium and other various heavy metals also present in crude oil-and in some cases added during processing-I need hardly comment on TEL....but there are all sorts of things being emitted into the environment-some of which we get concerned enough about to do something about-others are either overlooked or put in the too hard basket.

We also have a very bad habit as a species,  of panicking, banning something and introducing a 'cleaner, greener' substitute which turns out to be significantly inferior to the product it replaced-I give you lead free solder, low energy lightbulbs (the non LED type) and NiMH batteries as good examples....

 ChrisM


----------



## Nerd1000

ajoeiam said:


> I do hope that you're getting a lot more than 20x atmospheric pressure in even your gas engine. In a diesel engine it is even higher.
> 
> I wonder if there has been any measuring of the ozone caused by the use of electric motors in vehicles?
> 
> (Seems that there has but the quantities are presently being pooh poohed. Somehow I remember a huge brouhaha not even that long ago about the depleting upper atmospheric ozone caused purportedly by those vile automobiles - - - maybe we all just need to walk - - - ie get rid of all personal transportation! - - - no horses either!)


A bit off topic, but modern EVs invariably use some kind of three phase electronically commutated motor (usually induction motors or permanent magnet brushless motors), so the main source of ozone (sparking at the brushes of a DC commutator) simply doesn't exist.

Regards the ozone depletion issue, it was the CFCs in aerosol cans (and airconditioning units) that were the problem, not car exhaust. With ozone, it really is a matter of where. Ozone in the upper atmosphere is good because it absorbs UV rays from the sun, a topic close to my heart given I'm a white guy living in subtropical Australia. Ozone at ground level is bad, it basically acts like gaseous bleach and breathing it has predictable effects on your health.

As for peak combustion pressures, somewhere in the vicinity of 30 bar is probably reasonable for a model SI engine. Diesels could easily be exceeding 100 bar.

 The exhaust emissions from a model diesel are probably less acutely dangerous than from a model gas engine, there is generally going to be a lot less carbon monoxide to poison you if you're indoors. But the soot causes cancer, so try not to breathe too much of it.


----------



## ajoeiam

Nerd1000 said:


> A bit off topic, but modern EVs invariably use some kind of three phase electronically commutated motor (usually induction motors or permanent magnet brushless motors), so the main source of ozone (sparking at the brushes of a DC commutator) simply doesn't exist.
> 
> Regards the ozone depletion issue, it was the CFCs in aerosol cans (and airconditioning units) that were the problem, not car exhaust. With ozone, it really is a matter of where. Ozone in the upper atmosphere is good because it absorbs UV rays from the sun, a topic close to my heart given I'm a white guy living in subtropical Australia. Ozone at ground level is bad, it basically acts like gaseous bleach and breathing it has predictable effects on your health.
> 
> As for peak combustion pressures, somewhere in the vicinity of 30 bar is probably reasonable for a model SI engine. Diesels could easily be exceeding 100 bar.
> 
> The exhaust emissions from a model diesel are probably less acutely dangerous than from a model gas engine, there is generally going to be a lot less carbon monoxide to poison you if you're indoors. But the soot causes cancer, so try not to breathe too much of it.


Hmmm - - - no sparking even at starts?

Hmmmmmm - - - - soot causes cancer - - - - so does living. Even more so where the food you eat generally has so very often been modified from its original state.

The reassurance from our national inspector - - - - " . . . for the production of good wholesome food . . .  . " - - - - ya right - - - pizza pops anyone?

The analogy that I first heard some over 40 years ago was re: the making of bread.
The modern method if making bread is akin to taking a brand new luxury car to the crushers and then after the car's condensing to take it back to the rebuilding shop and then rebuild it trying to achieve 'like new' results.
Don't work much for the car - - - - and similarly for the bread.
(It doesn't help that the 'modern preferred' form of such is much closer to that of a dessert item from 4 or 5 hundred years ago.
'Real' bread - - - a.k.a. that made for the serious working guy - - - its bloody hard to find!!!)


----------



## Badhippie

Hello 
Here are the specific chemicals found in diesel 
smoke. 
Chemical contaminant    Note    Concentration, ppm
acetaldehyde    IARC Group 2B (possible) carcinogens    
acrolein    IARC Group 3 possible carcinogens    
aniline    IARC Group 3 possible carcinogens    
arsenic    IARC Group 1 carcinogens, endocrine disruptor[citation needed]    
benzene[1]    IARC Group 1 carcinogens    
biphenyl    Mild toxicity[citation needed]    
bis(2-ethylhexyl) phthalate    Endocrine disruptor[27][28][29][30]    
1,3-Butadiene    IARC Group 2A carcinogens    
cadmium    IARC Group 1 carcinogens, endocrine disruptor[citation needed]    
chlorine    Byproduct of urea injection[citation needed]    
chlorobenzene    "[L]ow to moderate" toxicity[31]    
cresol§        
dibutyl phthalate    Endocrine disruptor[citation needed]    
1,8-dinitropyrene    Strongly carcinogenic[32][33]    
ethylbenzene        
formaldehyde    IARC Group 1 carcinogens    
inorganic lead    Endocrine disruptor[citation needed]    
methanol        
methyl ethyl ketone        
naphthalene    IARC Group 2B carcinogens    
nickel    IARC Group 2B carcinogens    
3-nitrobenzanthrone (3-NBA)    Strongly carcinogenic[32][34]    0.6-6.6[35]
4-nitrobiphenyl    Irritant, damages nerves/liver/kidneys[36]    2.2[37][38]
phenol        
phosphorus        
pyrene[1]        3532–8002[37][39]
benzo(e)pyrene        487–946[37][39]
benzo(a)pyrene    IARC Group 1 carcinogen    208–558[37][39]
fluoranthene[1]    IARC Group 3 possible carcinogens    3399–7321[37][39]
propionaldehyde        
styrene    IARC Group 2B carcinogens    
toluene    IARC Group 3 possible carcinogens    
xylene§    IARC Group 3 possible carcinogens


----------



## Badhippie

Sorry should have said Diesel Exhaust


----------



## awake

ajoeiam said:


> Hmmm - - - no sparking even at starts?


No spark gap in the system.


ajoeiam said:


> 'Real' bread - - - a.k.a. that made for the serious working guy - - - its bloody hard to find!!!)


I've been making bread for the family for 20+ years. I started when my kids were toddlers, and now they won't eat anything else but home made bread!


----------



## minh-thanh

I have many intentions with this thread .
  But in the past few days, I'm not in the mood to talk about it anymore.
I really feel discouraged .


----------



## Stefan-K

minh-thanh said:


> I really feel discouraged .



I totally agree! A lot of Bla Bla about Things that have nothing to Do with the original thread. Sadly you find this behaviour more and more on this forum.


----------



## ajoeiam

awake said:


> No spark gap in the system.
> 
> I've been making bread for the family for 20+ years. I started when my kids were toddlers, and now they won't eat anything else but home made bread!


Grew up on mom's. Have made some here - - - need to back into that as well.
Wish there were more hours in the day though!!!


----------



## ajoeiam

Stefan-K said:


> I totally agree! A lot of Bla Bla about Things that have nothing to Do with the original thread. Sadly you find this behaviour more and more on this forum.



TL;DR
Well it is a common problem when you are talking with multi-dimensional people.

Getting frustrated with the rabbit trails will likely only hurt your enjoyment of the site.

Its easy enough to glance at and then ignore any message that you don't find interesting.
In fact there are more than a few threads that I find interesting that I haven't even posted on - - - I didn't think I had anything to add in the conversation to that point - - - still interested in the topic.


----------



## Stefan-K

Well, i'm pretty sure its not only my enjoyment of the site. I'm not the only one.... I think it would be much easier for all here if the Posters would stay at the thread theme. This is a Model Engine maker forum and that's exactly why i'm here. If i would like to read about the" life adventures " of others i'd look for a Yahoo Drama Chat room.


----------



## ajoeiam

Stefan-K said:


> Well, i'm pretty sure its not only my enjoyment of the site. I'm not the only one.... I think it would be much easier for all here if the Posters would stay at the thread theme. This is a Model Engine maker forum and that's exactly why i'm here. If i would like to read about the" life adventures " of others i'd look for a Yahoo Drama Chat room.



Making the site mono-dimensional has the following effect. 
In the thread "*Wanted bill of materials for Satra O-440* " 
there is an admission from one of the posters that the writer and the individual that was doing the castings (IIRC) only talked machining. 
Now the individual has died - - - - - and it is proving to be very very very difficult to find information that would have been very easy to find were the individual still alive. Presently - - - finding the information and who may have the rights and responsibilities thereunto is incredibly difficult. 

Life has shown me that when I put people in boxes - - - a la the Procrustean method - - - - I lose in the long term. 
I do not need to be everyone's bestie (modern vernacular for best friend) but knowing somewhat about them and their situation and some of their other interests helps me know them as a person. Our societies predilection for making people mono-dimensional is imo to be decried NOT extolled!! 

Herewith ends my involvement with this particular topic.


----------



## minh-thanh

When I started this thread, everything was fine
 During the process of building the engine, there were some opinions and arguments, ...and I was really annoyed
 After a lot of trial and error ... I succeeded with the diesel engine . And, again with the debate about "what is a diesel engine,...."
 After a lot of experimenting with my engine, I have learned a few things about it and want to share it with everyone. I know there are a few people trying to build their own diesel engine (with my design as well as their own design).
 For a person , English is the main language , it only takes them 29 seconds to write as I posted . But for me it took more than 30 minutes to translate and edit , translate and edit , trying to be as precise , concise and clear as possible
 And when I posted the part that was fine, it started again with the comments: " the toxicity of diesel engine smoke "    
 And maybe, someone will say: "My diesel engine will damage the ozone layer, poison the earth's atmosphere, or contribute to the destruction of life on earth...."
* If one is afraid of the toxic smoke of the engine, do not build any internal combustion engine, because all homemade engines do not comply with any emission standards.*
 Some comments are off-topic, it doesn't matter to me , But don't be like the comments that are happening to this thread .


----------



## Stefan-K

ajoeiam said:


> Herewith ends my involvement with this particular topic.



Cool! I totally agree.


----------



## GreenTwin

I burn diesel in my foundry furnace, and it burns cleanly (cleanly being a relative term), with no smoke at all.
I had some concerns about fumes from burning diesel, but it is not like I stand around and inhale the exhaust or anything.

But everyone should remember that if drive your car down the expressway in the US (or perhaps anywhere), you are breathing in tons of exhaust from the diesel engines that are in the trucks all around you.
Nobody seems to be concerned about that.

I did notice that the indoor air quality at the 2019 NAMES show was very bad.
They would announce over the loudspeaker every 30 minutes or so for everyone to turn off their engines so the smoke could clear, and they would partially raise an overhead door for a few minutes.
The combination of all the exotic fuels and fuel/oil blends being burned in all of the internal combustion engines affected my lungs and breathing for days after the show.
There is no place at NAMES to get away from the fumes.  The whole building is a "heavy smoking" section.
I am not complaining, it was a great show, but that was a toxic mix of partially burned fuel coming out of all those high-revving IC engines.
They need to keep a roll-up door open at all times at NAMES.

All that being said, I think the exhaust from a single scale model engine is negligible compared to any fumes you will breathe by just driving down the expressway.
So while I fully believe in using great caution with material data sheets for every foundry product I use, and I adhere to every safety warning about foundry products, I think with a single small scale engine, we need to realize that only a tiny amount of fumes are produced.

You can easily die from drinking too much water, but nobody is sounding the alarm about water and how toxic it can be.

Common sense must dictate safety.
I think if you did an analysis on a hamburger, or a grilled steak, or any fried food, you would be shocked at the number of potential carcenogenic things are in those (I don't often grille out for that reason, and I don't eat fried food often either, because I don't want to look like the Goodyear blimp).

We should all be safe in this hobby, but in a reasonable and logical way, with an appropriate amount of caution to match a corresponding danger.

Edit:
The trend these days is to go overboard about safety.
One guy from Australia told a story on a casting forum a few years ago about how his local council decided that all foundry sand was a deadly toxin that destroyed the lungs.  They were planning on banning all foundries and all foundry sand.
The guy went to the next council meeting, and spoke at the podium, and said "You are going to have a very hard time banning sand because our city is on the coast, and 100 yards from here are miles and miles of beaches with the very same sand as you are trying to ban".

There is too much fear-mongering these days about seemingly everything.
Awareness is one thing; obsessing about the toxicity of every substance on the earth is not necessarily reality.

.


----------



## Nerd1000

Indeed, for perspective: we can safely assume our models, with no emissions control, make 10- 100x as much nasty fumes as an equivalent engine with emissions control systems.

But who here has made a model engine bigger than 50cc? Even assuming 100 fold more pollution per cc, a 50cc model is not going to be much worse than a car with a 5L V8, and there are not shortage of people running those daily, vs our engines which maybe get run once a month on average. Application of common sense is all that is required.


----------



## Steamchick

Thanks Nerd, I agree with you about perspective. But maybe you are forgetting that since the mid-1970s, car manufacturers have been adding precious metal catalysts in car exhaust systems, and doing a lot of clever re-design inside the engines - and with fuelling and ignition strategies - so the CO NOW is around 1/1000th of the CO from just pre-emissions laws...
The emissions laws have also doubled the efficiency of the engine, so modern cars use less than half the fuel of "pre-emissions laws" engines.
Mostly, Modellers do not model such high tech modern beasts, but usually the "older" engine designs, and because of a "scale" (linear to surface area to volume) factor, these can be much dirtier than the full sized versions. But like smoking cigarettes, 1 won't kill you, but 60 years at 20 per day (400,000 fags)  probably will affect your health... = Perspective.
I run steam engines, using LPG fired boilers. If the burner is "wrong" (too rich), I hear the CO alarm in the garage, and turn off the gas and ventilate the garage. But if I start my Moto-Guzzi V50 (1979 version) in the garage, the CO alarm sounds almost instantly. Even a cloud of exhaust from outside the garage blowing into the garage will set it off! So many modern safety levels (scientifically developed for the legislators!) are much tighter than we appreciated when we grew up... I remember in bad weather, how, walking to school, we would sometimes cough because of the accumulated coal-fire smoke in certain streets... and when I cycled to work in the mid-1980s, passing a steel mill, I nearly collapsed one day from breathing fumes coming out of the open door to the mill! (I just managed to free-wheel into fresh air!) - I guess from a bubble of oxygen-free air? That was how life used to be. We don't NEED to replicate that with our modelling. The local model steam locomotives now have to run on "Smokeless" fuel... and smoking cigarettes and pipes is banned on the footplate of heritage railways with steam locos that now must use "smokeless" coal...! The engine-drivers and firemen must also wear anti-COVID masks! - You have to laugh!
Probably the worst thing that can happen is someone with an engine making a lot of CO (No smell!) runs it in an enclosed space... and falls asleep with intoxication. But if the smoke is sooty and smelly, one is quickly prompted to open a window or door to ventilate the space!
K2


----------



## ajoeiam

Steamchick said:


> Thanks Nerd, I agree with you about perspective. But maybe you are forgetting that since the mid-1970s, car manufacturers have been adding precious metal catalysts in car exhaust systems, and doing a lot of clever re-design inside the engines - and with fuelling and ignition strategies - so the CO NOW is around 1/1000th of the CO from just pre-emissions laws...
> The emissions laws have also doubled the efficiency of the engine, so modern cars use less than half the fuel of "pre-emissions laws" engines.
> Mostly, Modellers do not model such high tech modern beasts, but usually the "older" engine designs, and because of a "scale" (linear to surface area to volume) factor, these can be much dirtier than the full sized versions. But like smoking cigarettes, 1 won't kill you, but 60 years at 20 per day (400,000 fags)  probably will affect your health... = Perspective.
> snip



Your comment is quite interesting. 
I bought a VW diesel Rabbit (Golf in most of the rest of the world even at that time) in 1980 and averaged over 75 mpg (us) over the life of the vehicle. 
Drove other previously very abused gas pots in the 90s - - - with most I got a touch over 45 mpg. 
Drove a late 60's Mercedes 220D and in longer distance urban traffic was able to get into the same 45 mpg country and that was an over 3 ton vehicle. 

Today I drive a Chev Aveo - - - - I don't get into 40 mpg country. 
Every newer vehicle I look at - - - dunno if there are any that get into even 40 mpg country. 
Most are bragging about economy and they're in the mid 30s. 

Please - - - I need a list of these oh so wonderfully fuel efficient vehicles - - - I haven't been able to find them. 
What are the brands model and the years?


----------



## Badhippie

Just to be clear my comments had nothing to die with the toxic by- products of diesel exhaust. It was all about the harm the by-products of diesel exhaust cause to the internals of the engine. I am pretty sure that was clear when I was talking about seeing rod caps being corroded in half and rod bolts and other internals. It was about maintenance of a Diesel engine. See I don’t have a PHD in anything but what I have is about 40 years of experience working with Diesel engines. It comes from a professional level. Not under a shade tree in the back yard.


----------



## Vietti

I agree with Green Twin, the air at the 2019 NAMES show was really poor.  I asked the organizers more than once to open the roll up doors but they refused, something about security.  I suggested getting someone to stand by the door to provide security.  At previous shows the doors were at least partially open and the air was OK.

That being said, I was probably part of the problem by blowing smoke rings.  I really hope they  will put on the show next year, it was great!!


----------



## Steamchick

A Joe I am. I am an odd ball. I worked with Emissions testing (as well as loads of other different jobs) on new models for around 15 years.... So did not drive around comparing cars. But on  pretty accurate and repeatable test, had to report the results of testing production cars, for both emissions and fuel economy. So we measured the total fuel consumed during the legislation test. Quoted in gms per 100km. I saw fuel consumption of cars go from 185gms/100km to 100gms/100km. in that relatively short period. But I didn't drive your cars.... Maybe my scientific approach isn't suitable to relate to your world.
Obviously (to me), a car using 100gm of fuel instead of 185 gms of fuel, and meeting emissions regs that are exceedingly difficult to achieve, tightening every 5 or 10 years, will produce lower tailpipe emissions than the older models.
I understand the US of A follows a similar strategy for cars?
I was probably being too general in my statements, for which I apologgise.
Enjoy your motoring!
K2


----------



## GreenTwin

Badhippie said:


> Just to be clear my comments had nothing to die with the toxic by- products of diesel exhaust. It was all about the harm the by-products of diesel exhaust cause to the internals of the engine. I am pretty sure that was clear when I was talking about seeing rod caps being corroded in half and rod bolts and other internals. It was about maintenance of a Diesel engine. See I don’t have a PHD in anything but what I have is about 40 years of experience working with Diesel engines. It comes from a professional level. Not under a shade tree in the back yard.


I misinterpreted your post.
Sorry about that.
.


----------



## minh-thanh

I have a question :
  Does all the debate in this thread help someone who is and is going to build a diesel engine of their own?
My answer is : NO , What about your answer ???
 So, the whole argument...bla,bla ...for what?
to prove what ?
  Remember: this is a homemade engine forum
Reminders such as : Beware of high pressure oil in contact , run with all internal combustion engines in a well ventilated area .... simple , short . perhaps 1000 times more valuable than what is being discussed here.


----------



## stewart drummond

minh-thanh said:


> I have a question :
> Does all the debate in this thread help someone who is and is going to build a diesel engine of their own?
> My answer is : NO , What about your answer ???
> So, the whole argument...bla,bla ...for what?
> to prove what ?
> Remember: this is a homemade engine forum
> Reminders such as : Beware of high pressure oil in contact , run with all internal combustion engines in a well ventilated area .... simple , short . perhaps 1000 times more valuable than what is being discussed here.


i think these members just need some friends , instead get on a forum & gasbag about their (apparent) huge knowledge of everthing except model engines , gets way off topic real quick , solves nothing from the original poster , end up with pages of totally irrelevent crap , see it here a lot , in fact , most post get polluted (pardon the pun) just like this diesel post


----------



## Mechanicboy

minh-thanh said:


> I have a question :
> Does all the debate in this thread help someone who is and is going to build a diesel engine of their own?
> My answer is : NO , What about your answer ???



This also applies to the model engine, .. if you see a lot of smoke or a lot of oil spewing out of the exhaust, then it is an indication that there is something wrong with the model engine. Model engine with little or almost no smoke and good combustion = good economy on consumption and less pollution.


----------



## minh-thanh

If you read and understand my post #338 then it's really simple to solve the smoke problem
 Just increasing the force of the needle spring almost solves the problem
 With my engine , 19 mm diameter and 38 mm stroke and I said it has 10 cc , I don't care much about the 1,2,3 cc difference and who on the forums cares about that , who cares ?
  who cares how much fuel a 10 cc or 20 cc engine uses in an hour of running ? who cares ?
  who would care about comparing fuel consumption between 10 cc and 20 cc engines, who cares?
 Or simply: if a well-aligned engine consumes 20 ml of fuel for 10 minutes running, and with a similar engine that is not well-aligned it consumes 30 or 40 ml of fuel for 10 minutes, with that 10 or 20 ml difference, who cares ???
* I see no problem with my engine  , the problem is  you .*
 You know what is most important with homemade engines??
Most of the members of this forum or elsewhere, the most important :  when building and make engine run , and perhaps no one cares how much fuel it will take in 30 minutes or an hour run (I say " most of members "  because I don't know about you)
 Pollution problem again , Yes, my engine is very polluted 
   Again, This is a homemade engine forum , Please !!!


----------



## GreenTwin

I tend to get off-topic at times, and that happens on forums.
I try to not deliberately hijack threads, and split off a new topic if that seems appropriate.

The reason I post here is that I have learned a lot from all the talented folks on this forum, and I hope I have shared some useful information to others.
Its all about communicating ideas with others, and sharing information and ideas.

Discussion of a variety of aspects of model building is part and parcel to the hobby.
I would suggest that if you find someone's posts irrrelevant, just ignore them and move on with what it is you want to discuss/highlight/showcase.
Everyone has different motivations for what we do, and our interests are as varying as our personalities.

In my opinion, its all good, I enjoy it all; the builds, the discussions, the side talk; it is  fun interaction with great hobby folks.
Live and let live as they say.
.


----------



## minh-thanh

Hi GreenTwin !

Like I said , some side posts it doesn't matter to me , sometimes I learn something , and I thank you for your post !
  The problem is that some people here are trying to prove something and I really don't understand for what !?
  They go too far
   If you've looked at this thread, you'll find almost 80% of the debate are fruitless,
  As you have seen, with a lot of experimentation and time translating into English, just to share some information just hope it helps someone (or not) and the result is dozens of toxic information. harmful effects of smoke, pollution...


----------



## GreenTwin

You have a choice.
You can focus on the comments that don't necessarily have much to do with this thread, or you can focus on what you are doing, and share your work with others.
Sometimes I put on virtual "blinders", such as the ones they put on horses, so that the horse is not distracted, and can get its job done.
I enjoy your work, and your videos.  Great stuff for sure; you have talent.

Keep doing what you are doing.
Life can be a 3-ring circus; my advice is to focus on what you want to achieve, and keep moving towards those goals.
Stay focused; don't let the side shows distract you.

This is pretty much my motto for living my life too.

.


----------



## Bentwings

stewart drummond said:


> i think these members just need some friends , instead get on a forum & gasbag about their (apparent) huge knowledge of everthing except model engines , gets way off topic real quick , solves nothing from the original poster , end up with pages of totally irrelevent crap , see it here a lot , in fact , most post get polluted (pardon the pun) just like this diesel post


what kind of diesel are you planning 2 stroke 4 stroke. ? 
Davis company had model diesels many years ago. They use his special diesel fuel 2 strokes had a screw in the head so compression ratio could be changed on the fly. I never had one so don’t know the exact construction . I YHINK the screw moved a tight filling piston to achieve variable compression ratio. The fuel was reported as having ether in it . It was supposed to be tightly capped at all times . They has a Venturi  intake similar o glow fuel model engines ofvthe era.  The small engines could swing a pretty big prop for the size compared to glow fuel engine of same displacement . That’s about all I know of them . There were few at model flying fields . I was into screaming rpm glow engines and twin engine lanes at the time.


----------



## Richard Hed

minh-thanh said:


> I have a question :
> Does all the debate in this thread help someone who is and is going to build a diesel engine of their own?
> My answer is : NO , What about your answer ???
> So, the whole argument...bla,bla ...for what?
> to prove what ?
> Remember: this is a homemade engine forum
> Reminders such as : Beware of high pressure oil in contact , run with all internal combustion engines in a well ventilated area .... simple , short . perhaps 1000 times more valuable than what is being discussed here.


Personally, I like the discussion.  I doubt that the last bit of discussion helps build anything but it might help psrevent getting poisoned in you garage.  Maybe you are just having a bad day.  I know I have had a bad 3 days in a row from traveling and the airlines screw ups.


----------



## minh-thanh

*GreenTwin !
*


GreenTwin said:


> You have a choice.
> You can focus on the comments that don't necessarily have much to do with this thread, or you can focus on what you are doing, and share your work with others.
> Sometimes I put on virtual "blinders", such as the ones they put on horses, so that the horse is not distracted, and can get its job done.


 
Thanks for your opinion !
  That's a good idea, maybe I'll give it a try
Or simply start a new thread 
Another opinion: " Silence is golden " 

I'm a person who doesn't like to argue,  this topic I argue 10 times more than I've argued in 2 years in real life, it's too bad with me.
  Sorry that my arguments have bothered everyone. I'm Sorry !
   This is the last post in this thread .


----------



## Bentwings

minh-thanh said:


> *GreenTwin !
> *
> 
> 
> Thanks for your opinion !
> That's a good idea, maybe I'll give it a try
> Or simply start a new thread
> Another opinion: " Silence is golden "
> 
> I'm a person who doesn't like to argue,  this topic I argue 10 times more than I've argued in 2 years in real life, it's too bad with me.
> Sorry that my arguments have bothered everyone. I'm Sorry !
> This is the last post in this thread .


 I just Hightower another tidbi.  The Detroit big diesels had th gmc positive displacement blowers often fed by a turbo.  These were 2 stroke enginges very messy by today standards. Various attempts at making miniature replicas of these blowers have not been very good. One that has made them work is Conley engines. H gets positive boost but not much . I’ve followed various turbo charger constructions on the internet but these have not been very good. It’s hard to keep them together at very high revs and they simply do not flow much air. One attempt at a screw bore with 3D printed parts while cute could not inflat a plastic garbage bag. I’d guess even compounding them would not be very successful. Some impeller more or less fake turbo or centrifugal blowers work only to stir up the incoming air fuel
Mix so ok for that purpose . The design of these is pretty complex and the air itsel does not scale well . I have two model turbines and can spin them pretty fast but output air is minimal at best. So if you go after this aspect I’m just saying others have tried it and not succeeded but made some nicely machined parts. 

At on pint OS glow engines had a functioning positive displacement supercharge. It apparently worked as it was very competitive with other engines of the era. It was very sensitive o dirt or dust as I recall du to tight tolerances.  As I noted it was easy to just add more nitro to make a lot of power. I blew up a bunch of model engine hotrodding them like this but I did have fun.

Byron


----------



## GreenTwin

Open forums are a mixed blessing.
I have had people say "I want to post things without my thread being filled up with a lot of side-chatter".
There are forums where you can do that.

Then I have had people post to a forum where there is no side-chatter, and then they say "I am going to another forum, there is no activity here".

There is no free lunch, it can't be both ways.
You can post and get a lot of comments if you thread is interesting, or you can post somewhere with no comments for a clean thread, but then get no feedback.

For me, the feedback is the only way to learn new things.
To each their own.
I like this thread, or I would not be commenting on it, so there is that.

.


----------



## pirmin kogleck

has someone ever tried to use o rings on the injection pump plunger =? i made a injector tester a injection pump 
( plunger type) and injector close to find hansens measurements but my plunger gets slightly leaky after some time . here a video of the injector with the leaky pump . u can only see the injecotr but i think with a tight pump i would have a lot better spray pattern as i saw a much better mist in the first few testes before the plunger got leaky.i heard mr hansen maybe used o rings on his pump but i cant proof that as he do not share a lot of information but his videos are a usefull source, there only i could see his water feed pump used a o ring as a seal. maybe this is the way to go for a tight fuel pump. i try to achive about 35 to 50 BAR and i am very close to have a good working, mine already worked until it got leaky. the mist was very fine, much much finer than in that video i post underneath. but lets hope someone can help. i ordered me some o rings for watch crown repairs they come from 0.6mm up to 2.4mm diameter, and i hope they might help

i try to attach a video, not sure if it works


----------



## a41capt

I’ll be following this thread.  I’m also wondering if O-rings would work, and thinking that perhaps a hard nylon ring (or three) might stand up to the abuse if it didn’t have too much of an “overhang”.

Keep us posted!
John W


----------



## Stefan-K

Hi together 
I also built an Injection pump for a small Diesel engine. I used the dimensions that Hansen told in his Video. So its very small. I can Tell you that any Kind of o-Ring, be it Rubber or plastic does not work at All. It can not withstand the necessary high pressure. I could reach about 120 bar of Injektion pressure with this pump but only for a short time. Think about a running engine! The time when the fuel is injected is very, very short. There is no need to keep the pressure up for a long time. So if the pump is capable of building up a high pressure in a short time, enough to inject then that's OK. Its much more important to prevent the backflow of fuel with a good working check valve. Another important point is the pressure difference between the compressed air in the cylinder and the injected fuel. The higher the difference the finer the spray mist will be. 
Stefan


----------



## minh-thanh

Hi pirmin kogleck !
Because they only focus on the smoke of my engine in the last video
  If they   sit down and ask, "Why is there more smoke than in the previous two videos?" or something like that, they'll have some of my reasons for that. But now is not necessary .
Back to your question
After thinking for a while, I don't know if I should reply to you here or in Messenger
I know there are a few people who can answer your question, but I'm not sure if they've read this thread , or for some reason it's hard for them to answer you..
So
Like I said before, ( I couldn't find it in this thread) Yes, I tried with O-rings, but I don't really like it. , I haven't tried it with the engine but again just based on experience : With a   4 stroke engine you can use O-rings for piston because the pressure is not high - compression ratio 10-1 or 9-1 ... moreover with the worn O-ring it's like trap the air and keeping the engine at 4-1 or 5-1 compression and the engine running . But you said the pressure is 35 - 50 bar, which is very high pressure and it runs in oil, and that's why I don't like to use O-rings and based on my experience with several related jobs
Some of your questions in Messenger :
In the 2 videos you sent me, your injector and the way it spray are really good and I'm sure it will be fine with my engine: 100%.
About the material, I only tried it with brass for a short time, so I don't know if it's durable or not.
I suggest you use the material combination according to the table below for the pump piston and cylinder
( black : that was my last test , and it was really good . About metal standards , Steel SAE 1020... : I chose the equivalent because my country's standards are a bit different from yours , I really hate that . )
Again , about O-rings: I don't use it on engines and I haven't experimented with it much so my opinions on it are just suggestions , and based on my little experience on how the my engine  can run :
  If your engine has a low compression ratio and uses   ether in the fuel and gives early injection time or gives early injection time with high compression ratio- about 45 degrees before TDC seems fine.
because if the O-rings are worn, the pump will still create enough oil pressure to inject into the cylinder at the compression stroke 45, 40, 35, 30 degrees before TDC, because at that time the pressure in the engine cylinder is still low. Or you can also combine the above suggestions with brass cylinders

PS : I really hate you for bringing me back to this topic
  Now, more than 19,500 members know I hate you.







* Edit* :  Injection time: More precisely the time the lobe begins to contact the pump piston: 22 to 45 degrees before TDC


----------



## Mechanicboy

pirmin kogleck said:


> now my question :
> 
> has someone ever tried to use o rings on the injection pump plunger =? i made a injector tester a injection pump
> ( plunger type) and injector close to find hansens measurements but my plunger gets slightly leaky after some time . here a video of the injector with the leaky pump . u can only see the injecotr but i think with a tight pump i would have a lot better spray pattern as i saw a much better mist in the first few testes before the plunger got leaky.i heard mr hansen maybe used o rings on his pump but i cant proof that as he do not share a lot of information but his videos are a usefull source, there only i could see his water feed pump used a o ring as a seal. maybe this is the way to go for a tight fuel pump. i try to achive about 35 to 50 BAR and i am very close to have a good working, mine already worked until it got leaky. the mist was very fine, much much finer than in that video i post underneath. but lets hope someone can help. i ordered me some o rings for watch crown repairs they come from 0.6mm up to 2.4mm diameter, and i hope they might help
> 
> i try to attach a video, not sure if it works



Pirmin Kogleck..

The best solution: Lapped plunger piston of hard steel in the cylinder of cast iron with tight tolerance who are not allowing to leak the fuel, but keep the plunger lubricated toghether with the cylinder. 

Lap the cylinder first until all tool marks is disappeared and then lap the plunger piston and clean up free parts for lapping paste then try to fit into the cylinder carefully with oil on the parts, relap if the plunger don't fit into the cylinder. The plunger piston must move free and keep tight into cylinder without leakage. The edge on the end of the plunger pump must not be sharp, better a bit rounded to not scratch the bore and allow to lubricate without leakage.

The plunger piston must be longer than the bore to make less leakage and less side thrust on the cylinder caused by the plunger piston.

To example we can see at the injection pump in the Sabb semidiesel engine (Norwegian boat engine) has 6 mm plunger piston and the length of plunger piston is 100 mm, also the length is about 17 times longer than diameter. Pump stroke about 5-8 mm in the maximum full stroke. 

Then we can set the plunger pump to 34 mm in length if use 2 mm diameter in the model diesel engine if we calculate the diameter x 17= length.


----------



## pirmin kogleck

okay, coolthanks for all the answers! 

i try to stay with brass and steel same like mr hansen , i use plunger 2mm and 18mm long , the cylinder is drilled down untill the end of the square part. at first my pump generated perfect pressure and a very very even mist pattern ! almost lke fog from a micro fogger  for the garden....  i was so happy because it took me about 100 hrs to get there with several injecotrs and pump prototypes.

my main goal is to achieve same dimensions like find hansen and also i want to use the same material because he proofed it works . so i d like to stay with a brass cylinder and a steel plunger . in all the years i tried to reach out to find hansen i always got no answer, only one time , and this is about the o rings and he said i should use them in the pump.
someone said he used solder in the cylinder wich is true but only on his very first engine with very low pressure. so i will try to make a few o ring porototype pumps. and see from there what happens, i lapped about 4 or 5 plungers so far. all seem tight at first and start to leak after a few tests, my injectors are perfect , i use same dimensions as find hansen , it is easy to take measuremnts from the pics he provided.

i wait for a box of watch crown o rings from china to arrive, they come in sizes from 0.6 to 2.4mm and i think they are maybe worth a try. otherwise i will try use the mini tiny o rings from cheap gas lighters . they seem to have 2.7mm OD so i would have to drill and ream the pump cylinder a little bigger than find original. we will see . i keep u guys updated,


----------



## minh-thanh

*pirmin kogleck !*
If you have Mr Hansen's answer
and


minh-thanh said:


> about O-rings: I don't use it on engines and I haven't experimented with it much so my opinions on it are just suggestions , and based on my little experience on how the my engine  can run :
> *If your engine has a low compression ratio and uses   ether in the fuel and gives early injection time or gives early injection time with high compression ratio- about 45 degrees before TDC seems fine.
> because if the O-rings are worn, the pump will still create enough oil pressure to inject into the cylinder at the compression stroke 45, 40, 35, 30 degrees before TDC, because at that time the pressure in the engine cylinder is still low. Or you can also combine the above suggestions with brass cylinders*



I think you shouldn't worry too much about it .

Do the best you can - Trial and error....and I think you will
  About the ether, If your engine can't run with kerosene, you should try with some ether. when the engine run you will know more about it
  And then kerosene is no longer a problem for you.


----------



## Mechanicboy

pirmin kogleck said:


> okay, coolthanks for all the answers!
> 
> i wait for a box of watch crown o rings from china to arrive, they come in sizes from 0.6 to 2.4mm and i think they are maybe worth a try. otherwise i will try use the mini tiny o rings from cheap gas lighters . they seem to have 2.7mm OD so i would have to drill and ream the pump cylinder a little bigger than find original. we will see . i keep u guys updated,



To use O-ring the plunger piston must be mirror polished to not scratching the O-ring. Keep all parts clean before assembly. The nut who are holding the O-ring must be adjustable to keep tight if leakage is there and the return spring must be strong enough to return the plunger with tight O-ring.


----------



## pirmin kogleck

i didnt think about that so far. somehow truw but on finds waterpump u see the  o ring is in the bottom and there is no nut or anything. sure it is the water and not the injection pump but i think the o rings are the key. i looked up model excavator micro hydraulic pistons and they use o rings on the double acting systems ( i know not the same but i thought maybe it is worth a try, and like minh tanh said, trial and error, i have spend about 100hrs so far on the tester, pumop and injectors including drawings....so i think i have to spend another 20   


i will keep you updated


----------



## pirmin kogleck

@ minh than 

i wnt even try to uswe ether, i want it to run without, allthough i have a lot ether athome and some model aero compression engines, i dont want to get into the ether discussion now...kerosene or nothing ! thats my goal. it must be a true diesel , not a compression ether engine ,....


----------



## pirmin kogleck

have yozu tri


Mechanicboy said:


> To use O-ring the plunger piston must be mirror polished to not scratching the O-ring. Keep all parts clean before assembly. The nut who are holding the O-ring must be adjustable to keep tight if leakage is there and the return spring must be strong enough to return the plunger with tight O-ring.


ed it ? i mean have u made a pump and tried use o rings ? i have informations from a very very reliable persion and he mentioned he used o rings on all his plunger pumps. 2.7mm cyl. diameter , the rest is unknown of dimenions


----------



## Mechanicboy




----------



## pirmin kogleck

@Mechanicboy!

this makes sense on some bigger engines but i thinku underestimate the size of the pump, it is only 20mm high with the top art a bit more . and according to find hansens informations there is no o ring above the plunger , there is a housing for the plungerspring and a nut to secure the housing but no o ring is visibe there because there is a hole drilled for lubriicastion and u can clearly see no o rings on alkl his videos above the plunger. i can only assume that he grooved the plunger in lower section and uses a o ring there like he did on his water pump. the water feed pump is the same pum just scaled up and a bit different plunger but overall he mentioned that it shares the rest with the injection pump.

matereial barrss cly and steel plunger, o ring 2.5x1x0.5

cylinder bore 2.7mm 

thats it 

so i dint understand if he made a 2.7mm plunger piston aswell or a 2.6 or anything below and then fit the o rings , or if he uses a lapped plunger pistn and uses the o rings then on that lapped one so u have at least 2 secure ways to hold oressure one by lapped plunger and second the o rings . i ried to use o rings on 2,mm plunger so far i was not able to get it into the cylinder therofr i wait for tiny o rings. i cant await it...the chinese post is realy fast but this seems to take a century for me 

can u mark on my picture where u would put the o ring ? ps i want to stay with that design and materials


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## pirmin kogleck

it would be a milkrun for me to make a big injection pump. but the sizes we are talking are so small..for my first working plunger it tookme 4 try to get one good one and this one started to kleak, and find said himself it is impossible on our smallmachines and tools to get that perfect fit without lapping , and even with lapping it starts to leak at a certain point after time. thats why i am very convinced by the o ring method.


----------



## Bentwings

Mechanicboy said:


> Pirmin Kogleck..
> 
> The best solution: Lapped plunger piston of hard steel in the cylinder of cast iron with tight tolerance who are not allowing to leak the fuel, but keep the plunger lubricated toghether with the cylinder.
> 
> Lap the cylinder first until all tool marks is disappeared and then lap the plunger piston and clean up free parts for lapping paste then try to fit into the cylinder carefully with oil on the parts, relap if the plunger don't fit into the cylinder. The plunger piston must move free and keep tight into cylinder without leakage. The edge on the end of the plunger pump must not be sharp, better a bit rounded to not scratch the bore and allow to lubricate without leakage.
> 
> The plunger piston must be longer than the bore to make less leakage and less side thrust on the cylinder caused by the plunger piston.
> 
> To example we can see at the injection pump in the Sabb semidiesel engine (Norwegian boat engine) has 6 mm plunger piston and the length of plunger piston is 100 mm, also the length is about 17 times longer than diameter. Pump stroke about 5-8 mm in the maximum full stroke.
> 
> Then we can set the plunger pump to 34 mm in length if use 2 mm diameter in the model diesel engine if we calculate the diameter x 17= length.


I was going to suggest the same idea of a long piston in a very tight tolerance bore. You can probably lap this but I YHINK it better to be honed. Precision honing is pretty easy if you leave stock . It’s just like preparing combustion cylinders . I’ve used .003 “ stoke so called rough but smooth bore take about 1/2 of that for rough hone then about 1/2 of the remaining for sizing then the rest as “plateau “ finish sizing and finishing . This will get ride of all torn machined metal then provide a very smooth cros hatched final bore size . The piston needs a ground finish  what every steel or cast iron material . The long piston length to bore length gives the seal. Probably about .0002” clearance at room temp any shop that does honing could help with what they can do . If you choose hardened bores they use boron alloy “ stones” for 0 wear so the bores will be dead straight .  Automotive diesel pumps are very close fitting like this . O rings just don’t wok . I don’t realy think any type of split piston ring would be very good.


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## pirmin kogleck

i will say it again 

i want to stay with same material as FIND HANSEN ! 

his pumo :

brass cylinder 

steel plunger ( 18mm x 2mm ) 

it seems many underestimate the size of this pump .  made some pics and will send them ina  few minute !
i know how to lap model engine cylinders and pistons and how to make those hones, but i cant make a 2mm hone ! it is impossible.  could only make a alu plunger and use it for preposilh and then lap the piston to size


----------



## Mechanicboy

Bentwings said:


> I was going to suggest the same idea of a long piston in a very tight tolerance bore. You can probably lap this but I YHINK it better to be *honed*. Precision honing is pretty easy if you leave stock . It’s just like preparing combustion cylinders . I’ve used .003 “ stoke so called rough but smooth bore take about 1/2 of that for rough *hone* then about 1/2 of the remaining for sizing then the rest as “plateau “ finish sizing and finishing . This will get ride of all torn machined metal then provide a very smooth cros hatched final bore size . The piston needs a ground finish  what every steel or cast iron material . The long piston length to bore length gives the seal. Probably about .0002” clearance at room temp any shop that does honing could help with what they can do . If you choose hardened bores they use boron alloy “ stones” for 0 wear so the bores will be dead straight .  Automotive diesel pumps are very close fitting like this . O rings just don’t wok . I don’t realy think any type of split piston ring would be very good.



Lapping give much better precision to work in tight tolerances than to hone the parts. Read this link What is Difference Between Lapping and Honing? 

I lapped the pump piston/cylinder where I created the Wakefield mechanical lubricator for steam engine without O-ring. It works very well without leakage past piston/cylinder under high pressure. I selected the pump piston of high tensile steel and cylinder of cast iron in the Wakefield mechanical lubricator.


----------



## Mechanicboy

pirmin kogleck said:


> i know how to lap model engine cylinders and pistons and how to make those hones, but i cant make a 2mm hone ! it is impossible.  could only make a alu plunger and use it for preposilh and then lap the piston to size



To lap the 2 mm hole is no problem: Use brass or aluminium rod who are a light tight in bore + fine and ultra fine lapping paste to lap the hole. Lap until you feel there is same resistand in the whole length of cylinder. Be carefully. To get exactly 2 mm: drill 1,9 mm and lap the whole length and test with the 2 mm brass rod carefully there is no binding or conical cylinder inside. Surface must be mirrorlike surface. Next lap the plunger piston who are a bit larger in diameter than 2 mm and test to fit into the cylinder some times with oil after you has cleaned up both plunger piston and cylinder carefully. If the plunger piston goes a bit light tight in the bore, then lubricate with oil only and rotate plunger piston in the bore until the plunger piston goes through the bore without leakage into the bore. Take a pressure test and check there is no leakage with closed outled to injector (blindplug on outled to example).


----------



## pirmin kogleck

Mechanicboy said:


> To lap the 2 mm hole is no problem: Use brass or aluminium rod who are a light tight in bore + fine and ultra fine lapping paste to lap the hole. Lap until you feel there is same resistand in the whole length of cylinder. Be carefully. To get exactly 2 mm: drill 1,9 mm and lap the whole length and test with the 2 mm brass rod carefully there is no binding or conical cylinder inside. Surface must be mirrorlike surface. Next lap the plunger piston who are a bit larger in diameter than 2 mm and test to fit into the cylinder some times with oil after you has cleaned up both plunger piston and cylinder carefully. If the plunger piston goes a bit light tight in the bore, then lubricate with oil only and rotate plunger piston in the bore until the plunger piston goes through the bore without leakage into the bore. Take a pressure test and check there is no leakage with closed outled to injector (blindplug on outled to example).


u think i havent already tried that ? i already lapped my 7th plunger and housing just now and it failed again. like i said i have  information from the probalby most reliable guy and he uses o rings on all his engines since the early 1990s and they never failed he said. i just dont know if he made the o ring on the plunger or inside the liner. and pls as a reminder. i would like to stay with brass and steel as a plunger . and i d like to stay on same dimensions , so pls no other suggestions. the main goal is now to achieve 100% tight pump. not another pump with cast iron...no longer plunger....it must be 18mm plunger ( same bore depth ) +- 1mm bore depth . i found that when i drill 1.9mm and then ream 2mm H7 it is a hole about 2.02mm because my plungers fit as soon i reach under 2.023mm at 2.019 they are alreadx to loose and at 2.020 they start to work good , but only for short time once the brass is a bit peeled or ground by the plunger they get leaky... i hope my o ring set arrives soon. i ordered them from ebay. 12-Size Waterproof Rubber Watch Crown O-Ring Gasket Assortment 1000Pcs 1.4-2.8mm | eBay

with those o rings i should be able to fit one or two in a row on the 2mm plunger .when i make a samll groove in it ...well lubricated they last forever i have been told!


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## pirmin kogleck

here u can see the leak is slightly visible on the lubrication hole . this is usualy where the pump gets a drop of oil, in my case the fuel /kerosene forms small drops but it got worse after i messed around with a new plunger and now i have no plunger wich is tight, or i should better say the cylinder is now messed up and i had to make a new one , i tried that new one and it is also not good.....,it is a realy pain to geth that part done...i tell you guys ...i have made 4 injectors wich now all work realy well but the pump is what makes me almost cry and crawl on the floor in my workshop....it is so hard and a lot of pushbacks are involved until it might work. but i know it will and can be done.  i will upload a slow motion injector video on youtube the next days since it is to big to upload here.


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## Mechanicboy

pirmin kogleck said:


> u think i havent already tried that ? i already lapped my 7th plunger and housing just now and it failed again. like i said i have  information from the probalby most reliable guy and he uses o rings on all his engines since the early 1990s and they never failed he said. i just dont know if he made the o ring on the plunger or inside the liner. and pls as a reminder. i would like to stay with brass and steel as a plunger . and i d like to stay on same dimensions , so pls no other suggestions. the main goal is now to achieve 100% tight pump. not another pump with cast iron...no longer plunger....it must be 18mm plunger ( same bore depth ) +- 1mm bore depth . i found that when i drill 1.9mm and then ream 2mm H7 it is a hole about 2.02mm because my plungers fit as soon i reach under 2.023mm at 2.019 they are alreadx to loose and at 2.020 they start to work good , but only for short time once the brass is a bit peeled or ground by the plunger they get leaky... i hope my o ring set arrives soon. i ordered them from ebay. 12-Size Waterproof Rubber Watch Crown O-Ring Gasket Assortment 1000Pcs 1.4-2.8mm | eBay
> 
> with those o rings i should be able to fit one or two in a row on the 2mm plunger .when i make a samll groove in it ...well lubricated they last forever i have been told!



You used cylinder made of brass instead cast iron. The problem with brass: the gringing particle by lapping paste will be embedded in brass where is very difficult to clean up free from lapping paste. Hence you got leakage in short time.


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## pirmin kogleck

Mechanicboy said:


> You used cylinder made of brass instead cast iron. The problem with brass: the gringing particle by lapping paste will be embedded in brass where is very difficult to clean up free from lapping paste. Hence you got leakage in short time.


But my cylinder is only drilled and then reamed to 2mm H7

The plunger is then put to size and cleaned well in boiling water to prevent that i try to not use diamond paste!

I am aware of that and as u said the plunger has to have a mirror finish u where not right!
Such tight pressure fits are achievable more likely with  rougher surfaces. 
I try to show u some info on that ! 

I still think o ring is the best idea and worth a try.


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## pirmin kogleck

Groove Design: O-Ring Seals - Minnesota Rubber & Plastics
					

This resource will help guide your decision on Groove Design for your project; specifically, O-Ring Seals for Static and Non-Rotary Dynamic Applications.




					www.mnrubber.com


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## pirmin kogleck

In the link above it is mentioned wich roughness on surface has to be achieved for a O ring in a rotary or linear piston application.


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## ajoeiam

Re: use of o-rings - - - please see attached. 

Reading through the doc it would seem that using o-rings in an injection system is likely something fraught with issues. 
Speed of motion and the pressures involved would appear to be the issues. 

Now if you keep your piston motion slow and the pressures down - - - - hmmmm dunno how you're going to get a working engine doing that.


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## Stefan-K

Pirmin! 
Komm lass gut sein.Nicht aufregen. Du hast ja recht, aber es nützt nix diese Deppen hier zusammenzuscheißen. Das kapiert die Sorte von Leuten eh nicht. Ich hab auch schon was gesagt, hat aber auch kaum Wirkung gehabt. Am besten du ignorierst die, das ärgert sie am meisten.


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## minh-thanh

Hi Stefan-K !
  You wasted my time because of google translate 
Hi pirmin  !
Can I design an engine similar to Fin Hensen's ? May or may not  .
My design , With very little information ... , even stupid .. I will choose a way I can easily change : pump, diameter of Cyl , stroke... Because I need that for  : trial and error
When I make the pump : use O-rings ? brass cylinder ? cast iron cylinders, steel cylinders ?...?? and what materials to use for pistons, a lot of things I have to consider
Final decision : I choose the best way possible - because then I no longer care whether it is good enough or not .
   About O-rings and brass cylinders: I can't help you.
I don't like to comment on what I don't know. Just as I have no opinion about other people tell you must to do....
  So If you chose  O-rings and brass cylinders: trial and error is the only path you have to take.


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## pirmin kogleck

hy stefan , hy minh, thanks for comments...

1: i know it is useless to adress my thoughts to those peope wich eat our time ...


stefan , i reached out to you but never got reply ! 


minh: 
i wrote u message ,
i got email from the modeller in Malta today , he just told me today in the morning, i should use 2mmx18mm plunger  and o rings 2x1mm ( i think mister hansen confused himself  with his own measurements,because of his confuse tactic to not share a lot ... 2mm plunger and 2.7mm hole make no sense even with a 3.1.5.0.5mm o ring.....later hem mentioned somewhere even  that he then chaged to 4mm o rings ( the pump has 4.5mm diameter so i dont believe that . 

it ois a good idea to better not say anything than just recommend BUlsh*t based on zero experience or some Big engines. a plunger pump from a big engine might use this or that ...but in the end u cant just scale every part down...this would be a milkrun if i just have to scale things down..

Trial and Error is the only way to go...same on my injectors....it was a long long way...easy 100hrs with the pump and the prototypes i made wich never worked.

i will keep the post alive and try to post as soon i have o rings from china. 
by the way. i ordered mne red fiber gasket and punshed 3mm holes in 1x1cm squares , right into the center comes the hole ( could also be drilled ) , then i lined them up on a bolt and secured them with a nut , this went on to the lathe and then i sanded them...i got perfect round gaskets like find hansen... the red material is available on ebay inn several grades ! it is super good, much better than the brown i used on my pump now.

thats it for now 

regards 

Pirmin


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## pirmin kogleck

this is the gasket materials, i have 0.5 and 1mm , all u need is a leather belt punch to punch the holes and then cut 1x1 cm and the rest on the lathe,..,.









						0.5mm*120mm *850mm,Insulation gasket Red vulcanized Fiber knifes handle paper | eBay
					

0.5mm*120mm *850mm,Insulation gasket Red vulcanized Fiber knifes handle paper | Collectibles, Knives, Swords & Blades, Blade Parts, Supplies & Accs | eBay!



					www.ebay.at
				












						6 Stck. 1,0 mm*120 mm*120 mm, Isolierdichtung rot vulkanisiert Faser Isolierpapier | eBay
					

6 Stck. 1,0 mm*120 mm*120 mm, Isolierdichtung rot vulkanisiert Faser Isolierpapier | Collectibles, Knives, Swords & Blades, Blade Parts, Supplies & Accs | eBay!



					www.ebay.at


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## pirmin kogleck

ajoeiam said:


> Re: use of o-rings - - - please see attached.
> 
> Reading through the doc it would seem that using o-rings in an injection system is likely something fraught with issues.
> Speed of motion and the pressures involved would appear to be the issues.
> 
> Now if you keep your piston motion slow and the pressures down - - - - hmmmm dunno how you're going to get a working engine doing that.


 i can assure u that two persons wich had succes on their Diesel Engines used a 18x2mm Plunger with O rings. thats all i can say. i have no idea wich shore the rubber was , i have no idea about the travel of the piston in meters per minute / m / min and also no idea about the groove size and the corect o ring, i would have to do some maths here...but one of the modellers wich had succes used the o rings from the cheapest gas lighters, they seem all to use the same size o ring and i checked it , they are either 2.5x1x05 or 3x1.5x0.5 or 2.7x1x0.5mm ...so i think two in a row might work...like Minh said trial and erroro, right now on my table i have 3 injection pumps and i just wait for the o rings to arrive..i cant await it and started another diesel model aero engine ( comperssion ignition ) just to keep me busy


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## minh-thanh

GailInNM said:


> This has been a very useful and popular thread. Lets keep it that way by confining the posts to topics  relative to building model diesel engines. Many fulll scale experiences are also helpful and but should be limited to things relevant too model engines.
> 
> Gail in NM
> Moderator


 
Well that's correct and that's why when I started this thread I said :






  To me that is useful information.
And thanks to *Timar* and   others for the information on the experience on the big engines !


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## minh-thanh

Hi pirmin kogleck !

 There's one thing that I'm not clear on:
  Where do you use O-rings? Is it the same as in the picture ?


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## pirmin kogleck

GailInNM said:


> This has been a very useful and popular thread. Lets keep it that way by confining the posts to topics  relative to building model diesel engines. Many fulll scale experiences are also helpful and but should be limited to things relevant too model engines.
> 
> In the next few days I will be cleaning up this thread to removing or editing non relevant posts including personal attacks and responses to them.  As my time is very limited right now due to cleaning up water damage to my house from a broken irrigation water supply line I am asking the other moderators to assist in this effort. We may make a few mistakes doing this so if you think you have been treated unfairly contact one of us and we will try to resolve the conflict.
> 
> I will remove this post when the cleanuo is complete.
> 
> Thanks for your cooperation.
> Gail in NM
> Moderator


i will try to take my posts out... thanks for your  message .  regards from vienna !


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## pirmin kogleck

minh-thanh said:


> Hi pirmin kogleck !
> 
> There's one thing that I'm not clear on:
> Where do you use O-rings? Is it the same as in the picture ?
> View attachment 136555


no on the plunger in the bottom, cut a groove into the plunger and fit the o ring. this might needs a littler testing and some refinements.


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## pirmin kogleck

hy guys, after a little research i was able to find some information about the A frame Gasoline engine from BENGS MODELLBAU ( a german engine brand and modellshop wich sells casting for hit and miss and other engines and steym engines etc) they developed a engine called Jonas wich also uses a plunger pump, a bit larger than the one i try to get run propperly  but it seems to work, the pump delivers fuel from the tank up in a second small tank underneath a carb, wich alsmost looks like a displacement lubricator from a steam engine....anyway...the pump uses an o ring, this is what i found out and i found a pic from Mr. Bengs personall build, the pump is located in the bottom left .


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## pirmin kogleck

here a video of my injector at work ! 
but this was with a lwaking pump, at first as thwe pump was tight it was much better than that but i think this video shows that it is possible to make em as small as find hansen did ( body is about 12mm ) needs a non return ball vlve and a 0.94mm needle with a M1 thread at the last 1/3 with two small m1 nuts to secure . the hole drilled is 1mm 










						Worlds Smallest True Diesel Injector in Slow Motion !!! True Diesel Model Engine injection
					






					youtube.com


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## minh-thanh

Hi !
Don't try to force it to create really high pressure,
  Injection time is about 45 degrees before TDC ( + , - ) , I think it will be fine .
  Because at that time, the pressure in the cylinder of the engine engine was very low and it doesn't put too much pressure on the pump  or the O-rings
( My goal is to do the best I can because I like   and I need it for a lot of testing. )


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## pirmin kogleck

thanks for that info! i think i did exact that mistake that i forced tomuch out of the pump..., and my thoughts about it are as follow: 

when u hit the injection tester with the finger, it cant generate the same momentum as a injection pump cam ! the cam hits the pump much faster and shorter time, so i think it will be fine , but i still need a new pump cylinder because mine now leaks. you are maybe right  at 45deg before tdc the pressure is quite low and i also thought maybe i will be fine with my pump. because the injectors proofed to work , so we will see .. i will wait for the rings and then i can report and tell the difference. i just would like to have my pump sealed becase i dont want to have a small fuel pit underneath the engine when runnning aswell , you know ...kerosene smells  not pleasant and it would look much better if there are no leaks, same with steam engines, when the gland packing is not tight it looks not good when there is water and steam leaking everywhere...


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## minh-thanh

With O-rings and brass cylinders : If you want to create really high pressure to inject   at 22  or 20...degree before TDC,   you will make  wear them out in a short time and damage the O-rings.
So 45 degrees ( +, - ) before TDC seems fine
 Edit :
So you don't need to test your injector with high pressure.
build an engine and test : trial and error !


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## pirmin kogleck

okay. i also researched a little about this topic and thewre are o rings for exact th<t aplication wich use a harder rubber shore ( the grade of the rubber ) ...trial and error ...


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## minh-thanh

pirmin kogleck said:


> * you are maybe right  at 45deg before tdc the pressure is quite low*



You can't say: "*maybe right*.."
    Because it's obvious , You must say : *It is correct*


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## pirmin kogleck

@ minh ! 
i deeply apologize ! yes you are correct! 



 pls dont kill me !


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## minh-thanh

pirmin kogleck !!

We've talked  informations homemade diesel  engine : Oil pump ... - and I hope it's helpful to you .

Another : About your previous comment :



pirmin kogleck said:


> @ minh than
> 
> i wnt even try to uswe ether, i want it to run without, allthough i have a lot ether athome and some model aero compression engines, i dont want to get into the ether discussion now..*.kerosene or nothing ! thats my goal. it must be a true diesel , not a compression ether engine ,...*.



With me -  the general rule about diesel engines : all engines , if it injects fuel into the engine at compression stroke- whatever fuel it is, ether or not, kerosene or diesel, whatever gets the engine running is true diesel .
  If you have success with this engine will you deny other engine use ether : that is not true diesel ??? and you would say engines that use ether in fuel are engines: compression ether engines ???
  There's one more thing I hate: if someone says their engine or something they do is the prettiest, the smallest, the best...bla bla ..., or the world's smallest. .
Always There is someone make it better !
  Think about that !


----------



## pirmin kogleck

it is just my goal to make it run as a Diesel ! 
in model Airplane /rc plane hobby there are so called diesels, and i think the topic was already discussed here . i just would like to have it run as a diesel like Mr. Hansen did . i used the terminology true model diesel or worlds smallest refering to model engine because when u look for just diesel injecotr or model diesel u get many other videos not related to the engine type we try to build, this is why i used this terminology ( "worlds smallest" and "true Diesel") i think it was also Mr. hansen wich used the Word "true Diesel" because if u search for model diesel , then youtube redirects you to the Rc airplane engines, wich i also do like, i have many of those Model Diesel rc engines , very small some under 0.2ccm ) those rely on the ether , but since we try to copy rudolph diesels system or more i should say the injector after Prosper Lòrange and the self ignition from diesel, i like to use True Diesel to not mix it up with rc model diesel  engines...


----------



## ranger

To improve the surface finish of the pump bore, if the valve end was detachable, you could perhaps try ‘Ball sizing’ - ‘Ballizing’, whereby a correct size hardened ‘ball’ is forced through the bore to correct any taper, and improve the surface finish. Apparently to an almost mirror finish. With a softer material such as brass, perhaps  an ordinary ball bearing might work?


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## pirmin kogleck

that is unfortunatley impossible because if the ball gets stuck there is no way to get im back out, the jhole on the bottom is only 0.5mm no chance to use such a think wire to get that ball back out . i will keep that in mind and maybe try ona test cylinder


----------



## ranger

Yes, trying to remove the ball from the bottom of a blind hole would be,’Interesting’, to say the least. But if the ‘cylinder’ was separate from the ‘valve block’, it would be a straight forward operation. Another possible advantage having a separate cylinder would be, you only have to replace the cylinder and maybe the plunger, if you wanted to try different methods of sealing, (or mess something up). Another thing which may help, could be, ‘anti extrusion rings’, either side of the ‘O’ ring, (if you can get them in the size you need).


----------



## minh-thanh

*pirmin kogleck .*

If I talk about " true diesel " , maybe some people will hate me including you .Sure .
So, Ok.. Let's put that aside, but remember what I said.
Back to main topic,



pirmin kogleck said:


> thanks for that info! i think i did exact that mistake that i forced tomuch out of the pump...,


  This issue I talked about before, you did't read or skim through....



minh-thanh said:


> Hi pirmin kogleck !
> If your engine has a low compression ratio and uses   ether in the fuel and gives early injection time or gives early injection time with high compression ratio- about 45 degrees before TDC seems fine.
> because if the O-rings are worn, the pump will still create enough oil pressure to inject into the cylinder at the compression stroke 45, 40, 35, 30 degrees before TDC, because at that time the pressure in the engine cylinder is still low. Or you can also combine the above suggestions with brass cylinders
> 
> * Edit* :  Injection time: More precisely the time the lobe begins to contact the pump piston: 22 to 45 degrees before TDC



Please sit down and re-read what I said, if you don't understand : ask , because what I said may not be clear and my English is very bad and use google translate.
Regarding the O-rings and brass cylinders: I think you've got a pressure of 50bar, you're doing very well.
Wear problem : Like I said , don't try to put too much pressure on them , you also sit down and check the cylinders and pistons : how do they wear , why do they wear so fast ? .....
  Let's make a part : lobe, motor ....combine them and the lobe will rotate at 500 , 700 ..rpm and use them to test the oil pump . If your oil pump can be ok for 10 ..15 ..min running , with medium pressure for a nice spray pattern it will be fine


----------



## GailInNM

With the assistance of other moderators and the support of forum members I have removed or edited about a dozen posts in this thread.

Some of the affected posts were not offensive but were removed or edited because they were no longer relavant as they were referencing posts that had been deleted.

Looking at the recent posts I think that this thread  is back on track. Lets keep it that way so we can all learn from it while enjoying our hobby.

Thank you to all the forum members for all your t support.

I will remove this post in a few days.

Gail In NM, moderator


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## Mechanicboy

pirmin kogleck said:


> it is just my goal to make it run as a Diesel !
> in model Airplane /rc plane hobby there are so called diesels, and i think the topic was already discussed here . i just would like to have it run as a diesel like Mr. Hansen did . i used the terminology true model diesel or worlds smallest refering to model engine because when u look for just diesel injecotr or model diesel u get many other videos not related to the engine type we try to build, this is why i used this terminology ( "worlds smallest" and "true Diesel") i think it was also Mr. hansen wich used the Word "true Diesel" because if u search for model diesel , then youtube redirects you to the Rc airplane engines, wich i also do like, i have many of those Model Diesel rc engines , very small some under 0.2ccm ) those rely on the ether , but since we try to copy rudolph diesels system or more i should say the injector after Prosper Lòrange and the self ignition from diesel, i like to use True Diesel to not mix it up with rc model diesel  engines...



pirmin kogleck..

The *diesel engine*, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-called compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). (Read again   it does not say: injection or carburetor in these engines)

Rudolf Diesel wrote this in his patent No. 608,845, dated August-9, 1898 : _My invention has reference to improvements in apparatus for regulating the fuelsupply'in slow-combustion motors, and inparticular to internal-combustion engines adapted for carrying outthe process described in my prior patent, No. 542,846, dated July 16, 1895, which process consists in first *compressing air or a mixture of air and neutral gas or vapor* to a degree producing a temperature above the igniting-point of the fuel to be consumed, then gradually introducing the fuel for combustion into the compressed air while expanding against resistance sufliciently to prevent an essential increase of temperature and pressure, then discontinuing the supplyof fuel and further expanding without transfer of heat.

US608845A - Internal-combustion engine  - Google Patents - US542846A - diesel  - Google Patents_

In plain text, a diesel engine is a compression engine that causes the air to rise to a high temperature before the fuel is ignited and *not* how the fuel is supplied into the engine whether it goes via carburetor or injection. Nor a specific fuel since Rudolf Diesel wrote either it is solid, liquid or gas that could be fed into the engine and ignite by the heated air in the engine. So-called dual-fuel diesel engines or gas diesel engines burn two different types of fuel at the same time, such as a gaseous fuel and diesel engine fuel. The diesel engine fuel ignites spontaneously due to compression ignition, and then ignites the gaseous fuel. Such engines do not require any type of spark ignition and work in the same way as regular diesel engines.

What we choose to use injection or carburetor for diesel engine:
*Heavy atomizing fuel* is supplied via injection.
*Lightly atomizing fuel* is supplied via carburetor (Model diesel engine, diesel-powered chainsaw for example Comet, Husqvarna or Jonsered chainsaw.)

Glowplug make diesel engine easy to start up the diesel engine when it's difficult to atomize the fuel and there is not enough heated air to ignite the fuel in colder area or in winter period.

In the small model diesel engine with injector need light atomizing fuel due we need better atomizing the fuel and be easy ignited  by heated air since the model diesel engine has great loss of heat than large diesel engine.

Ether in fuel has a purpose in model diesel engine: Easy to hand start engine. In fact, model diesel engine can run without ether which you can easily find in Youtube.


----------



## minh-thanh

One more thing I want to tell : I have never lapping pistons with   cylinders if it has small diameter . Because the steel or stainless steel for the plunger with small in diameter ( < 3 mm )   it will bend and get stuck in the cylinder ... if it has a little difficulty moving in the cylinder . Even with the rod tool (a hard steel 3 mm , 2.5 mm, 2 mm ..) you can break it with tight tolerances
 With large diameter cylinder - I have lapping piston with cylinder ?? Yes yes , only with a cylinder diameter of 16 mm . But only once or twice. And I don't like it. All - a lot of the cylinders I make for me and some friends (from 6 to 22 mm) including engines and cylinders, I always do  my way: make the cylinders fit the pistons or back and I never lapping
I only rotate ,move back and forth the piston in the cylinder with oil a few turns_ , *If the  plunger actually moves through the entire cylinder with the oil but there is still a little - very little - not smooth*_
  At this step you really have to be careful, the cylinder, plunger and oil must be really clean, a little mistake will ruin all your efforts and time.
 If someone advises me: lapping plunger with cylinder has < 3mm diameter with tight tolerances. With my experience I very much doubt that
 So be careful with any advice lapping  pistons with cylinders if it has small diameter and with tight tolerances


----------



## pirmin kogleck

minh-thanh said:


> One more thing I want to tell : I have never lapping pistons with   cylinders if it has small diameter . Because the steel or stainless steel for the plunger with small in diameter ( < 3 mm )   it will bend and get stuck in the cylinder ... if it has a little difficulty moving in the cylinder . Even with the rod tool (a hard steel 3 mm , 2.5 mm, 2 mm ..) you can break it with tight tolerances
> With large diameter cylinder - I have lapping piston with cylinder ?? Yes yes , only with a cylinder diameter of 16 mm . But only once or twice. And I don't like it. All - a lot of the cylinders I make for me and some friends (from 6 to 22 mm) including engines and cylinders, I always do  my way: make the cylinders fit the pistons or back and I never lapping
> I only rotate ,move back and forth the piston in the cylinder with oil a few turns_ , *If the  plunger actually moves through the entire cylinder with the oil but there is still a little - very little - not smooth*_
> At this step you really have to be careful, the cylinder, plunger and oil must be really clean, a little mistake will ruin all your efforts and time.
> If someone advises me: lapping plunger with cylinder has < 3mm diameter with tight tolerances. With my experience I very much doubt that
> So be careful with any advice lapping  pistons with cylinders if it has small diameter and with tight tolerances


thanks for your thoughts...it is indeed very tricky and like i mentioned in one of my private messages Find Hansen said himself it is almost impossible to lap a such small Plunger in our Home Workshops with out machines . he said itr woill work for a short time and then it get lweaks, many times he had tried and failed and also many many people before and after him tried this and had little succes....i also believe that u are 100% right that the pump i have built has the pressure i need and it wokrs fine, it is just the thing that i want too have it sealed so the engine does not drip fuel on the wood plate and everything looks fine...i am sometimes very very picky and if something doesnt work i cant go to bed without fixing it


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## minh-thanh

pirmin kogleck said:


> . he said itr woill work for a short time and then it get lweaks, many times he had tried and failed and also many many people before and after him tried this and had little succes....i also believe that u are 100% right that the pump i have built has the pressure i need and it wokrs fine, it is just the thing that i want too have it sealed so the engine does not drip fuel on the wood plate and everything looks fine...i am sometimes very very picky and if something doesnt work i cant go to bed without fixing it


 
  Because brass is soft and easy to machine . 
You can easily create a beautiful brass surface, harder with cast iron and   more harder with steel .
Brass cylinders and plunger no O-rings or with O-rings are not suitable for too high pressure in cylinders with high compression ratio (18-1 or higher) and injection time around 22 before TDC. That's why I use cast iron or steel for the cylinder.  
  But with moderate pressure - enough to inject well into the cylinder at about 45 degrees before TDC in high compression engine it should be fine. That's why Find Hensen chooses a 45 - 50 degree  inject  time before TDC for him engine


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## pirmin kogleck

okay guys !

i had succes with my Pump configuration , i used some tiny  o rings and now my pump is 100% tight and sealed ! no leaks! pump domension is 18mm plunger, 2mm mm bore  , 4 o rings  like a ringed piston. thats it for now

here a video of the injecotr at full pump pressure 









						Model Diesel Injector Test/ injector (12mm)
					

Here i am Testing my Scratchbuilt injector and injection pump ! I am pretty confident now that i could get a 10ccm Diesel engine run on that setup! Material ...




					www.youtube.com
				




i have no idea how much BAR my pump delivers but it should be okay now ! 

i also machined the flyball governor for the engine build already becaue i was bored and have to wait for my material to arrive


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## pirmin kogleck

Here the flyball governors for the diesel build!




One will be for sale i made it extra but have no need for it ! If someone is interested pls send me a message .


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## minh-thanh

The way it inject looks fine, but it seems to inject the way it does when there's a sudden high pressure , I not sure 
 Have you checked the tightness of the injectors ?
  The tightness of the injector is really important !!! (I told you about this on facebook group and I also spoke on this forum) If the injector is not completely sealed then you cannot control the injection time, affect the pressure in the  cylinder. engine and oil pressure in the oil pipe - Don't expect it to be more tightness  with the high pressure in the engine cylinders.
 Simply connect your injector ( at the injector inlet or outlet ) with compressed air with a pressure of about 2 - 3 bar and immerse the injector in kerosene ( if using water to test, you should clean it after checking ) no air coming out at the other end   it is ok .


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## pirmin kogleck

okay guys , small progress here.
since i have to wait for some material and a bit more money for a Mig welder i decided to make all the small parts for the engine one after another , so far i have the governer, the pump and injectors , 

last item is the Sight feed Oilers


check it out


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## minh-thanh

pirmin kogleck !



pirmin kogleck said:


> ..i am sometimes very very picky and if something doesnt work i cant go to bed without fixing it


 
I like the way you try to solve the problem.
But , sometimes do something else ..... to clear your mind , and then come back to solve the problem , it will be better .
   Anyway, the parts you made are really nice !


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## pirmin kogleck

Thank you ! i am very proud on the parts i make, you must know i started machining 6 months ago, i had Zero knowledge about machining metal parts or anyx machine ( i am a cook   ) but to be honest, it is a big challenge to copy Find hansens engines if u want to "replicate the engines " since i have no measurements and plans , i have to use his pictures and videos only and sometimes it takes many many hours to make a drawing, check the video again, check the measurements and then check the proportions....now some people would say i am disrespectfull when i replicate an engine from Find but in fact it is Respect.here in ASustria we have a saying : "Imitation is the sincerest *form* of recognition"


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## Peter Twissell

I completely agree!
All of us building engines today are using the knowledge gained by others who built engines over the last century and more.
We are all standing on the shoulders of giants.
I am sure that if our predecessors could see what we are doing, they would be happy to know that their work continues to inspire thousands of home engine builders.


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## pirmin kogleck

i am a bit sad about the fact how the combustion engine is viewed to out younger generation, i want at least build a small engine for myself and maybe for my kids someday to teach them....to show that without those nice beautiful pieces of engineering art we could not life in such a wealthy society.Rudolph Diesel wrote a very interesting book with the title :Solidarity (The Rational Economic Salvation of Mankind). i realy love to walk on the footsteps of such great human beings, and maybe will learn something on my way..


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## minh-thanh

Peter Twissell said:


> I completely agree!
> All of us building engines today are using the knowledge gained by others who built engines over the last century and more.
> We are all standing on the shoulders of giants.
> I am sure that if our predecessors could see what we are doing, they would be happy to know that their work continues to inspire thousands of home engine builders.


 
That's for sure !
    All  engines I did,  it were just  re-prove what others have done or at least they prove that it was possible to do in the past ,   as Pete Twissell said: "over the last century and more."


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## minh-thanh

Hi All !
Just curious... so far, has anyone been in the process of building a diesel engine ?


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## Bentwings

minh-thanh said:


> Hi All !
> Just curious... so far, has anyone been in the process of building a diesel engine ?


haven’t seen much on them lately Davis diesel had model engines but he had his own fuel. Not gas station fuel I think it had plenty of ether in it .  They did not have high pressure pumps jus Venturi carbs like glow engines they did have variable compression ratio. It was part of getting these to run well . That’s the limit of my knowledge of them. They were not very ocular .


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## Nerd1000

minh-thanh said:


> Hi All !
> Just curious... so far, has anyone been in the process of building a diesel engine ?


I bought your plans, thinking I would build one. But since then I've gone crazy enough to want to put my own spin on things, so I'm partway through designing a slightly larger (32mm bore x 38mm stroke) diesel with a Bosch style injection pump and indirect injection. Lots of lessons learnt from your work though!


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## bluejets

minh-thanh said:


> Hi All !
> Just curious... so far, has anyone been in the process of building a diesel engine ?


George Punter from Australia built a miniature Lister Diesel engine a couple of years back.
Video here........


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## minh-thanh

bluejets said:


> George Punter from Australia built a miniature Lister Diesel engine a couple of years back.
> Video here........



Yes, I knew,
  But I want to know if anyone is building the engine since I finished mine


Nerd1000 said:


> I bought your plans, thinking I would build one. But since then I've gone crazy enough to want to put my own spin on things, so I'm partway through designing a slightly larger (32mm bore x 38mm stroke) diesel with a Bosch style injection pump and indirect injection. Lots of lessons learnt from your work though!



Making the engine a little bigger doesn't matter, as long as it runs
  Are you building or designing ? are there any pictures ?


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## Nerd1000

minh-thanh said:


> Yes, I knew,
> But I want to know if anyone is building the engine since I finished mine
> 
> 
> Making the engine a little bigger doesn't matter, as long as it runs
> Are you building or designing ? are there any pictures ?


Still designing. Mostly working on the cylinder head right now.


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## minh-thanh

Looks great !
If possible, keep it updated


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## ajoeiam

Nerd1000 said:


> Still designing. Mostly working on the cylinder head right now.


Hmmmm - - - is that freecad?

Might be good if you started a new thread for your build - - - (please?).


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## Nerd1000

ajoeiam said:


> Hmmmm - - - is that freecad?
> 
> Might be good if you started a new thread for your build - - - (please?).


It is and I will, once I'm happy with the general design (I don't have a block yet!)


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## pirmin kogleck

hy guys , i have no progress so far but i was able to get in touch with a nice guy on facebook wich is willed to help me and we decided to maybe share some informations...for now ijust moved in a new appartment and have to set up all my new tools and stuf, it will take me some time until i will finish my engine, i see it as a long term project, i have no need to rush ! i also make a compression ignition Model engine with 0.63cc wich only needs cylinder lapping and piston and contra piston fitted and the ports milled on rotary table...i will soon respond on this topic.


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