Mini diesel engine.

[tim9lives]

Good luck. Very cool project

 

[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.

 

[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

 

[minh-thanh]

tim9lives !
Thanks !
Peter Twissell !

are very difficult to achieve a good finish with.

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

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

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

 

[minh-thanh]

Hi All !!!
I think I made an injector

 

[ajoeiam]

Hi All !!!
I think I made an injector

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

 

[Mechanicboy]

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

 

[minh-thanh]

ajoeiam !

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..

 

[minh-thanh]

ajoeiam !

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....

 

[ajoeiam]

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.

 

[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.

 

[Badhippie]

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

Thanks Tom

 

[minh-thanh]

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.

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.

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 !

 

[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}.

 

[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

 

[minh-thanh]

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 .

 

[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

 

[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.

 

[ALEX1952]

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

 

[Richard Hed]

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.