# Tiny I.C. Engine



## putputman

Feb 20 2010 -- I HAVE REMOVED ALL OLD PRINTS AND REPLACED THEM WITH REVISION "B" PRINTS. THEY SHOULD SHOW UP IN MY FIRST 6 POSTS. THERE IS ONE SET OF NOTES AND 21 PRINTS. 


This is a tiny I.C. engine that I just completed. I first saw this engine at the LeSueur, MN. Pioneer Power Days last summer. A gentleman by the name of Jim, from Des Moines, IA. Had a couple small engines that that were beautifully built and run like a dream. Jim and I have had many conversations since we first met and he has provided me with build information talked me through several problems I had completing this engine. Jim, I can't thank you enough.

This is the smallest I.C. Engine that I ever tackled.






It has a 3/8 dia. Bore and a 1/2 inch stroke. Getting two valves and a spark plug in that small area proved to be quite a challenge. 





It was the first time I tried making a spark plug. The body was made from 12L14 with a Teflon insulator and .035 music wire electrode.





The fuel mixer was also quite small. The spray bar has .018 fuel inlet and a .020 cross hole. The needle is a .025 dia sewing needle.





Jim recommended using S/S Machine & Engineering for a CDI unit for the electrical end. Knowing absolutely nothing about CDI units, I contacted Roy Sholl, owner/operator of SS. I have to say that I have never worked with any supplier that has been as patient and helpful as Roy. I highly recommend him for anyone needing an ignition system for their models. 

The CDI unit is very small and I was able to conceal it in the Corian base I made for this engine. The unit puts out a good spark. I ended up using a Hall Effect for my ignition.





Had a few problems getting the engine to run and stay running. I used an O-ring on the piston. The valves sealed OK. It took several tries to get the intake spring pressure correct. Once it started it run pretty good, but after a short time it would quit. I would have to choke the heck out of it to get it started again. After several runs, it wouldn't even start. I replaced the O-ring and it took off again. Apparently the finish in the bore was too rough and would ware out the O-ring quite fast. I put a good finish in the bore and haven't had a problem since. 




This could be an ideal I.C. Engine for the people that have mini lathes & milling machines such as Sherline and Tieg.  

View attachment Tiny I.C. Notes -- rev B.pdf


View attachment Tiny 1 Frame -  rev B.pdf


View attachment Tiny 1A Crank Ret. --  rev B.pdf


View attachment Tiny 2 Gas Tank -- rev B.pdf


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## Speedy

WOW thats very cool :bow:
does he sell the plans?
I have a sherline mill and taig lathe. im always looking for engines


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## gbritnell

Great job on that little popper Arv. I built one a little bit bigger than yours and the only way I could get the rpm down was to make bigger flywheels. The spark plug looks like it's working well.
gbritnell


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## cfellows

That's pretty amazing, Arv. You are definitely versatile in the types of projects you finish. Does it get hot pretty quick?

Chuck


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## ironman

Great looking and sounding engine Arv. Any available plans? Be a neat project. Congrats. Job well done. ironman


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## Maryak

Wow, I admire your patience. :bow: :bow:

Best Regards
Bob


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## Tin Falcon

where can we get plans is that jims design . It looks a lot like an Uphur I have a set of those.
Tin


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## Quickj

PutPutMan (Arv),

That is awesome. Hopefully I will get the chance to see it in person at one of the shows here this year. 

Looks good, Runs Good.

Jim


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## rake60

Nice Arv.
Very nice! :bow: :bow: :bow:

Rick


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## Jtrain

Wow, that is awesome.


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## doc1955

That is very impressive to say the least. It really purrs nice!
When is the show you mention and where is LeSueur, MN?
I attend the show at Rolagg MN every year and a show locally well just north of here. I've been away from the shop life for the last 7 or 8 years just now getting back into it after missing making chips. Isn't it a rush when you fire up an engine for the first time. I would bet firing that little beauty the first time was a really big thrill.
I am very impressed with your work!


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## rudydubya

Really nice and compact Arv.  My compliments on a well-done project.  :bow:

Rudy


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## slick95

Very well done Arv :bow: :bow: :bow: It just purs right along. SUPER!!!

I'm not sure I could even see all those little parts but I sure would like to have a try at a small engine like the "Tiny".

Jeff


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## Quickj

doc1955  said:
			
		

> When is the show you mention and where is LeSueur, MN?



Doc,
The show in LeSueur, MN is the LeSueur Pioneer Power Show, This year it will be held August 27-29 2010. LeSueur is about 60 miles Southwest of Minneapolis, so quite a haul from JamesTown, N.D. Here is a link to their website,

http://www.pioneerpowershow.com/

They do have a separate building called "Miniatureland" for the Model engine builders, and every year there are 12-20 in attendance.

I attended maybe 8 shows last year from Winfield Kansas to Rollag, MN and I think I ran into Arv at half of them.

Jim


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## stevehuckss396

Nice job Putput!

I have been thinking about a 4 cylinder project that would have a bore of .313. What size thread is on your spark plug? I made a 6-56 thread plug that worked but i dropped it and it is no longer with us. Also how did the teflon machine? I tried corian and it machines well but is real easy to snap if to deep a cut is taken.

I also like that ignition. I use it on the Peewee and bought the same unit for the Hodgson 9 cylinder project. They work great.


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## b.lindsey

That is amazing work Arv and it runs so well as the video clearly shows. Thanks for sharing the pics and vid!!

Bill


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## putputman

Thanks to everyone for the compliments and comments. It has really been a fun & satisfying project, however frustrating at times. Smaller isn't always better & easier.

The design is essentially a 1/2 scale of the Upshur horizontal but with a lot of changes.

I did redraw every detail prior to building the unit. The drawings are not professional or even up to industry standards. I merely draw them so I can understand them and assemble the engine on the computer before I cut steel. I will post them as soon as I can check them over and figure out how to post them as PDF files.

Chuck, to answer your question, I really haven't run the engine long enough to see how hot is really gets. It does warm up quite fast. 

Steve, the spark plug has a 10-32 thread, which seems too large for the cylinder size, but I cheated a little. After the threaded portion I necked it down to 1/8 for the remainder. That was the only way I could fit the plug and two valves in 3/8 dia. The Teflon machined OK but it was difficult to press onto the metal housing. It was like pushing a noodle. The plug shown was too short and did not enter the cyclinder area. The one in the engine is a little longer.







View attachment Tiny 3 Cylinder -- rev B.pdf


View attachment Tiny 4 Crank -- rev B.pdf


View attachment Tiny 5 Flywheel -- rev B.pdf


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## NickG

Arv, wow, I love your engine, it's a little cracker. I would be very interested to see your drawings when you get around to it. I've been looking at the odds and ends hit & miss which is a design I love but also like this one so I need to try and make things as simple as possible when I do mine!

Nick


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## solver

Arv, pressing the teflon part to metal housing is much easier, if you use 'guiding tube', that has same  a bit larger diameter, as spark plugs hole has. So the teflon doesn't have a chance to spread out.


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## putputman

OK fellows, need some help. I tried loading 7 PDF files this morning and maybe 1 got uploaded. I must be doing something wrong, but don't know what. Need some simple instructions on how to load more than one at a time or more than one in the same folder.

Also, once I load some PDF files will I be able to add more later to the same group and maybe even remove some absolete files.




View attachment Tiny 6 Gears -- rev B.pdf


View attachment Tiny 7 Piston -- rev B.pdf


View attachment Tiny 9 Head -- rev B.pdf


View attachment Tiny 8 Con Rod -- rev C.pdf


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## putputman

I just looked at the downloads. It looks like I made a real mess of things. They are all separate downloads and some do not have titles. 
I was hoping to download enough prints so anyone who wanted could get started on their build while I finished the rest of the prints. Maybe it is best to remove the one that got loaded and wait until they are all completed. May take awhile. 
It also appears that once I upload them I have no way to manage them. ??? ???  ??? 

View attachment Tiny 10 Valve Cutter -- rev B.pdf


View attachment Tiny 11 Valve -- rev B.pdf


View attachment Tiny 12 Spark Plug -- rev B.pdf


View attachment Tiny 13 Spark Plug Asm -- rev B.pdf


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## kustomkb

Cool Engine Arv. Well done!

Thanks for sharing your designs.


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## GailInNM

Arv,
The way I handle them is to make them attachments to a message. This is done under the "additional options" at the bottom of your post while you are typing it. You can add up to 4 items there and there is a size limit on the file size. If you edit the post later, you can delete an attachment and then upload a new one. As I update drawings that is what I do. Works better for me than putting them in the files section. If you want to see how that works, the Lobo Pup Twin drawings are in PDF format attached to the first two posts in the thread at:
http://www.homemodelenginemachinist.com/index.php?topic=5872.0
Gail in NM


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## Krown Kustoms

Very nice Arv, I have been waiting to see this one.
It sounds great.
-B-


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## doc1955

Quickj  said:
			
		

> Doc,
> The show in LeSueur, MN is the LeSueur Pioneer Power Show, This year it will be held August 27-29 2010. LeSueur is about 60 miles Southwest of Minneapolis, so quite a haul from JamesTown, N.D. Here is a link to their website,
> 
> http://www.pioneerpowershow.com/
> 
> They do have a separate building called "Miniatureland" for the Model engine builders, and every year there are 12-20 in attendance.
> 
> I attended maybe 8 shows last year from Winfield Kansas to Rollag, MN and I think I ran into Arv at half of them.
> 
> Jim



Thanks Jim!


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## solver

Arv, that's just amazing how small the engine is :bow:.

It may well be the smallest four-stroker, that i've seen running .


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## putputman

Gail, I think that is exactly what I was looking for. I have all the prints drawn but many of them have been altered so I can get certain dimensions that I need. I have a DRO on the mill and work from center point in all directions now & then. I will review & correct them so that others can use them. If I can post them like you have done, then when everyone is satisfied that all the necessary information is there, I can upload a complete file.

Thank you so much Gail. I think I have mentioned it before but I am much more comfortable with a Bridgeport than I am with a computer. 

Right now it is cocktail hour for us oldtimers. Will post prints tomorrow. 


View attachment Tiny 14 Spray Bar -- rev B.pdf


View attachment Tiny 15 Needle Asm -- rev B.pdf


View attachment Tiny 16 Mixer Body -- rev B.pdf


View attachment Tiny 17 Stand Off -- rev B.pdf


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## GailInNM

Hope that helps, Arv.
Please understand that my motives are purely selfish. It's a great engine and I want to see the drawings.
Gail in NM


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## NickG

Arv,

I agree, can't wait to see the drawings. Thanks for sharing

Nick


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## putputman

Thanks to Gail, I am going to try to provide enough photos and prints to build the Tiny I.C. engine. The first PDF file is a series of written notes that may or may not help you. I'm sure many of you have your own way of attacking a project and this is just one way.

The first part is the frame. It is a fairly easy part to build and once it is done, you get the feeling you are well on your way.






Next is the combination base and gas tank.





The next part would be the cylinder. I have had good luck following the procedure for putting the cylinder sleeve into the hopper frame on several engines that I have built. It even works better on the larger bore sizes.



View attachment Tiny 18 Rocker Arm -- rev B.pdf


View attachment Tiny 19 Linkage -- rev B.pdf


View attachment Tiny 20 Cam Follower -- rev B.pdf


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## GailInNM

Nice drawings, Arv.  Thm: Thm:
Thanks for posting them.
Gail in NM


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## putputman

Well I've got a few more prints and notes available.

You might want to tackle the gears next. I suggest this in case you have to make or purchase any tools to get the job done.

The whole size and c-bore in the larger gear is up to your discretion. I happened to have some little shoulder screws on hand so I made the gear to fit. You may have to make your shoulder screw if you have none available.





The connecting rod is a little different than most because of the space available on this small engine. I made a horizontal clamp instead of a vertical one to reduce the size under the crank.





The head is probably the most difficult part on the engine. There is a lot to crowd into a small area.

There are a couple of set ups that are difficult to explain in words so I'll show some photos.

Set up for locating & drilling the spark plug hole.





Set up for locating, spot facing, drilling & tapping the spark plug hole.





This is what you should end up with.


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## bearcar1

Arv, hey thanks a million for taking the time to put these drawings together for us. That is a delightful engine and perhaps I may undertake its construction one of these days. Beautiful workmanship you've done there, I am a bit surprised at the big end cap configuration but at that size it seems to be adequate enough for its purpose. Not sure I would have ever thought of that, thanks again for sharing the ride.

BC1
Jim


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## solver

Thanks Arv for the video and posting the plans . 

What fuel is it that you are using?


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## putputman

Thank you for your interest in this project. I hope the prints and notes are providing enough information for your build. 

I am using Coleman Camping Gas with a little bit of Marvel Mystery Oil added for lubrication. I'm hoping the oil will reduce the wear on the o-ring


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## putputman

I was attempting to scan and load some more prints and the scanner software "took a crap". I'll have to see if I can find the disc that came with the scanner. It has been several years since I loaded the software on this PC.


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## putputman

OK, found the old disk and reloaded the software for the scanner. Hopefully it will last long enough to complete this project.

These valves are probably as small as you will have to make for any engine. I cheated a little and used some hardened punch pins that we used to use for core pins in plastic molds. They have a 3/32 shank and a 60 degrees swaged head. The head had slight seams on the taper so I had to grind a smooth surface with my simulated tool post grinder. Also had to grind a groove for the retainer as they are too hard to drill cross holes in them.
You will probably be making your valves from scratch using drill rod.











While I had the compound set up at 30 degrees, I machined the valve seat cutter out of drill rod. 
This insured that I had the same angle on the valves and valve seat. George Britnell's post is a very good guide for making valve seat cutters.







Next is the spark plug. I was always intimidated at the thought of making a small spark plug, but after following some of the post on HMEM by more experienced builder than me, I decided to give it a try. It actually wasn't that bad.

I used 1/4 hex stock for the body, Teflon for the insulator, & .032 music wire for the electrode.
Because of the cylinder size I was very restricted to the spark plug size. I chose to use a 10-32 thread and then neck the rest of the body down to 1/8.






Machining the Teflon with that small dia is kind of difficult. I decided to start by turning a dia. Down to 1/4" and drilling a .032 hole through it. Next I machine the brass ferrule & soldered a piece of music wire in it. By pressing the music wire into the Teflon it help stiffen the Teflon.
To provide additional support for machining I drilled a .032 hole in the center of a piece of 3/16 brass rod. I then held the brass rod in the tail stock chuck. There was about .10 length of music wire sticking out of the Teflon that would stick into the brass rod and support the assembly, just like turning between center.






After turning the body and the insulator the pieces can be pressed together. The smaller .079 dia Teflon should just be a nice slip fit in the body. If it is too tight, it will just bunch up in the body.

Lastly is machining the overall length and finishing the electrode end. I machined about 1/32 off each side on the end of the spark plug down to the dia of the electrode. There is some Teflon left that you will have to remove with a knife. Final result is a surface gap spark plug.


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## GailInNM

Thanks for the update Arv. I really appreciate the effort. It is such a nice engine and a nice write up that you are doing.

I have been saving the files to a local folder as you upload them. Makes it easier to view and review.

I have noticed that although you discuss some of the parts in the notes the drawings for them have not been posted. It appears that you have not uploaded drawings 4,5,7 and 10. If this is intentional just ignore me as I am not trying to bug you about it. 

Gail in NM


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## JRNYMAN2LMAYKER

This engine is ideal for those of us that like to work small but I am sure it will hit the hearts of all. I have downloaded the posted drawings so far and I am guessing there are more on the way, right? 8) Can't wait!!!!!!


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## putputman

Geeeez Gail, that's strange, I got all the prints, don't know why you don't.  ???  :big:  :big:  :big:

All kidding aside, thanks so much for catching that. My mind and my hands don't always work together. Being the notes included these parts I will just add them to this post.

Yes Greg, there are more prints coming. Once everything is uploaded and some of you have time to review and comment on the prints, I will upload the entire package in one PDF file. That will make it easier for everyone.

Again Gail, thanks for all the help. I couldn't have posted any of this without your instructions. Keep an eye on me until this is done.


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## solver

Arv, thanks again for an excellent writeup :bow:.

To me, smaller the engine, the more interesting it gets, especially on four-strokers.


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## JRNYMAN2LMAYKER

thanks so much for the prints.


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## doc1955

Thanks for posting the drawings and all the good documentary on the build.
Very impressive.

PS. Ordered a CDI ignition and got it on Saturday haven't had time to try it out yet
Thanks for posting the info on it. I've been wanting to make a smaller package for my ignition box.


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## putputman

Solver, Greg, & Doc, thank you for your comments and I hope you will get started on the engine soon. 

Gail, a karma to you for keeping me on track.

Doc, I am really happy with my CDI unit. As I mentioned before, I have little to no knowledge on how these things work so the information & help that Roy Sholl provides is invaluable to me.


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## gbritnell

Arv, excellent job on the spark plug, well the whole engine for that matter. The small stuff is fun but it takes some ingenuity to get things done, like your rod cap. 
george


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## doc1955

I too noticed the rod cap and thought thats a new twist I haven't seen before one for the old memory bank. :bow:


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## NickG

Yes, thanks again Arv,

I will certainly be having a good look at these drawings. I was thinking the other night about trying to use a glow plug for my first engine, and, if possible a petrol vapour carb - do you think these two things would work or would the glow fuel not vapourise enough?

If not, what about 1 or the other?!

I'm just trying to take out potential stumbling / stopping completely blocks for my first I.C which I think would be ignition system and carb!

Nick


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## putputman

George, Doc & Nick, thanks for the compliments. They are really appreciated.

The rod cap was a desperate solution to a space problem. After it was done, I kind of liked it also.

Nick, I have never had any experience with a glow plug. I'm sure there are plenty of people on this site that have though. The little I know about a glow plug is that they are primarily used on 2 stroke engines. 

As far as vapor carbs., I have built Jan Ridders' design and also one like Chuck Fellows design. They both work fine & I love them. I don't know if something like that would work for this small of an engine. Maybe you will be breaking new ground for all of us.

Don't be scared of the carb for this engine. It is small but a simple design. I will be uploading prints for the fuel mixer soon.


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## putputman

Back again with a few prints. Getting close to the end. I have been getting some real nice comments on these posts and I thank all of you. I would like to make any necessary corrections on these prints before I put the entire package into one PDF file. I need some feedback from anyone who has found errors or missing information of the prints. You can post or PM any corrections.

The fuel mixer is a very critical part of this engine, and I guess for any engine. This one has some pretty small holes to drill so you might have to prepare for that if you don't have the drills, taps, & dies.












The spray tube is made from 1/8 dia. brass. Turn the .085 dia. And cut 2-56 threads for the required distance. Next drill the .025 and .018 holes. It is important the drill to the correct depth so the gas flow work properly. Turn the .062 dia groove. 





The needle assembly and mixer body are pretty easy.





I couldn't find any 1/16 plastic tubing locally so I ended up buying a 10' piece from US Plastics. Kind of an overkill, but maybe I'll find use for the rest of it someday.


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## Maryak

ppm,

 :bow: :bow: :bow: :bow:

I wish my eyes and my machining skills were up to the task.

Best Regards
Bob


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## bearcar1

OMG Arv, will you stop with the assorted pocket change for size references please!! I'm starting to get migraines thinking in such scale, damn that thing is 'tiny' (ya' think that's why it is named "TINY"?) Nice work, and thanks once again for making the drawings available to us non-lilliputians
 Rof}

BC1
Jim


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## SAM in LA

ARV

Thanks for sharing. 

I have added your engine to my bucket list. 

No matter how hard I try, I can not catch up.

My bucket list gets longer each day.

Thanks again.

SAM


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## solver

There is one possible alternative source of small dia fuel tube:





Above is long-nose, butane gas stove igniter. It has ~150mm(~5.9") length of about 1mm id tube.

That might be a bit too small size, when compared to 1/16", but it seems to stand the gasoline anyway.


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## putputman

The final prints deal with the exhaust actuation. Most of the parts are fairly simple and won't require any special instructions.





What you use for an ignition system is up to you. I personally felt that a small engine like this one deserved a small hidden ignition system. Most of the engines that I have built in the past used points and either an old buzz coil or a large automobile coil. Either way they are just physically too large.

My friend Jim recommended looking at the S/S Machine & Engineering CDI units. I contacted Roy Sholl, owner/operator of S/S, and he recommended the complete CDI ignition system which included the coil, battery pack with rechargeable batteries, charger, switch, spark plug wire, hall sensor & magnet, and all Futaba connectors. 





After receiving the unit I made the base that would house all the components. I guess there is plenty of instructional information to install & hook up the system for anyone with electrical knowledge, but in my case, there were a couple emails and phone conversations between Roy & myself to make sure I didn't mess it up. I just can't get my head around electronics. 






I started out using contact points but couldn't not get the engine to run. It was a system similar to what Jim is using and his runs very well. Roy is trying to figure out why mine wouldn't run. 

After failing to get it running and not knowing if the problems were electrical, fuel, timing, or quality of the build, I then switch to using the hall sensor and magnet. I made a plastic holder for the hall sensor and mounted the magnet in the side of the brass flywheel. After adjusting the timing to fire at TDC, the engine immediately run.


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## putputman

This is about all I have at this time. There have been a lot of downloads but I have no idea if anyone is building this engine. If anyone finds errors in the drawings or needs additional information, please feel free to contact me. 

I do plan to upload the complete package of notes & prints once they are updated to correct any mistakes or omissions. This will be within the next month.

If you are pleased with post and information provided, a karma would be very much appreciated.

Best of luck & I hope to see some new Tiny I.C. Engines on HMEM.

Arv (putputman)


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## doc1955

putputman  said:
			
		

> This is about all I have at this time. There have been a lot of downloads but I have no idea if anyone is building this engine. If anyone finds errors in the drawings or needs additional information, please feel free to contact me.
> 
> I do plan to upload the complete package of notes & prints once they are updated to correct any mistakes or omissions. This will be within the next month.
> 
> If you are pleased with post and information provided, a karma would be very much appreciated.
> 
> Best of luck & I hope to see some new Tiny I.C. Engines on HMEM.
> 
> Arv (putputman)



You've got it Karma to you. Yes when I finish my current build I'm thinking I want to tackle it next even though I said to myself "self next time bigger motor less squinting". :big:

I really like that little engine you've created and want to thank you for the postings and tips!


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## Seanol

You have Karma!

It will be a couple engines before I get to this but a hearty thank you for your contribution Arv!

Regards,
Sean


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## bearcar1

Indeed a K'point to you sir, a mere pittance for all of the work you have put into this and tenfold the enjoyment I have gotten from same. I currently have something in the works but this one may be the next project afterward. The doggone thing is just so darned, well,,,, tiny. I admire the way that you hid all of the electronics in the base as well Arv. Nicely done. Thm:

BC1
Jim


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## JRNYMAN2LMAYKER

Thanks a million Arv for your work and offer of the plans. This will make an excellent project to sharpen my CAD skills.

Greg


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## putputman

I have replaced all the old PFD notes & prints with new ones at revision "B".
They will include any omissions and corrections that were on the first set.

The changes that were made should not have caused any problems for those of you who have already started this build.

Again, I want to thank all of you for your comments and help with thread.


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## bearcar1

Gosh Arv, I just 'HAD' to go back and watch your video again and dog gonnit, I was mesmerized once again. That thing is so slick looking and it seems to run a treat. Well done sir :bow:


BC1
Jim


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## putputman

Well BC1, the best medicine I know for that bug is to get out in the shop and start building one of your own. After seeing Jim's run last summer, that was my only cure. ;D


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## bearcar1

Yeah I know Arv, of course you are correct but I have two other irons in the fire at this time and am afraid if I begin something else I won't finish what I already have started and the cyle would continue. That is a pretty slick engine. 

BC1
Jim


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## GailInNM

An Air Cooled Tiny is under way. 
This engine is all Arv's geometry with only changes to suit my personal preferences and tools so no drawings or other details will be supplied.

To make it air cooled, the water hopper was removed leaving a 1/4 wall for the cylinder to mount to. The cylinder was made of cast iron with fins for cooling and the head mounting holes were extended through the fins to the tapped face of the frame. 

For personal preference, the flywheels are fitted with taper lock hubs instead of set screws for mounting. If you look at the split taper inserts you will see 5 holes. Three of them are to pull the taper lock into the female portion of the hub and two of them are tapped to release the male part from the female part to disassemble or adjust. All holes are for 0-80 threads.

The crankshaft was extended 1/16 inch one one end to better fit my flywheel as my hub is a little thicker than Arv's. This is for the side of the engine that has the gears. The other end was extended 3/8 inch to allow room for a pulley to mount to drive some sort of external load if desired. The crankshaft also has counterweights incorporated. This is really cosmetic on an engine of this size and intended RPM, but as I turned the crankshaft from 3/4 inch diameter bar stock the metal was already there so very little extra work was required. 

The fuel pick up tube in the fuel tank is offset from the center line as I think it will be easier to install the fuel tube. It also let me use a close fit hole in the fuel tank for the tube as I could insert it from the inside and rotate it into position. 

On the frame, I put an extended fuel filler tube instead of the threaded plug. I may put a cap on the exposed end but I have not decided on that. I will wait to see how it looks after assembly. 

This how things are at the end of day 16 since first metal was cut, but there were 5 days I was not in the shop. Most everything up the cylinder head are machined, but will need some finish work done for cosmetic purposes during assembly. 

Gail in NM


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## NickG

Gail - wow, where did this come from?! Very nice, have you started your own build thread or are you just going to post on the bottom of this. Arv, once again nice design and nice to see somebody has already got well on with a build of your engine.

Well done to both of you. :bow: I will start looking at this after my poppins are done so may be a while off yet!

Nick


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## GailInNM

Thanks Nick,
I am just going to post here in Arv's (PutPutMan) excellent thread. It is the same engine functionally and the drawings are here in this thread. Besides it shows how to make something that looks a lot different without changing any functional dimensions. maybe encourage others to play a bit with design.

Arv: Only one bust found in the drawings so far. The spacing between the crankshaft webs is shown as 0.156, the same as the width of the connecting rod. I thinned the crank webs down to put 0.187 between them. A quick scaling of one of your photos leads me to believe that you thinned the connecting rod down to 0.141 to provide the clearance. Either way will work, so no big deal except that some way must be used to provide some clearance. If the parts are built to the drawing, the connecting rod could be slimmed down afterwards so it should not mean anyone having to remake any parts.

Gail in NM


----------



## rudydubya

Arv and Gail, your work is inspirational. :bow:

Rudy


----------



## JRNYMAN2LMAYKER

Dang Gail, you beat me to the punch!!!! I have redrawn the cylinder for an air cooled version as well, however, the design is slightly different than what you have. It appears more like the version Hamilton Upshur used on his 3/4" bore model. I am curios to see what you actually come up with as far as springs are concerned. Per Arvs' reccomendation I have been scrounging the local hardware stores for different spring sizes and lengths. 
i have all of the materials gathered and rough cut into a sort of kit form but just waiting to have all the stuff before making chips.

Good work my friend........

Greg


----------



## putputman

Gail, coming along good. I like your flywheels. The spoke pattern really looks nice. I think your tapered locks will work better than the set screws. I know when I used that design on larger engines, the flywheels run true. 

I am curious as to why you made a three piece flywheel instead of a two piece one. 

I will check the drawings on the crankshaft & con-rod again. I know I changed some dimensions on the crankshaft after I built the second one. I guess if that is the only mistake left on the drawings, I am happy.

Looking forward to see that one running.


----------



## GailInNM

Thanks Rudy, but Arv is the inspiration and I am just playing copy-cat. This is just what you need if you ever want to go down from your Upshire in size.

Greg, I will be looking forward to your build. For springs I will probably just wind my own. Years ago I bought a box of one pound coils of music wire at a local going out of business of a machine shop. Wire sizes from way too small to way too big. If we get the springs nailed down I can mail you some wire to wind your own.

Arv, The three piece flywheel is because I hate to set up the lathe to cut the taper in the flywheel bore. I have an old CNC lathe so I made a production run of the male and female taper locks many years ago so I just have to put a straight bore in the flywheel and Loctite them together. I have not finished turned the rim of the flywheel so I will do that on an arbor after the hubs are mounted. Actually this bit me this time as I only had one hub set left in the drawer so I made a run of 25 more so I won't have to do it again for a long time. Probably they will last until I can't build models any more. I have both a CNC lathe and mill, but most of this engine will be built manually. The flywheel hubs and flywheel spokes are about all so far. I will probably turn the spark plug bodies on the CNC lathe also as it is easy to thread close to a shoulder with it.  

On the spark plugs, I am planning to change the thread from 10-32 to 10-40. I have taps and dies for both, but 10-40 is a sort of standard for model spark plugs and commercial ones are available. It won't do any good in this case because of the extended nose needed for this engine won't let us use a commercial plug any way, but it keeps things the same around here. 

Gail in NM


----------



## putputman

Gail, I checked my engine against the prints and found that I had cut the connecting rod down to .140 width. That gives it the necessary clearance. 

I removed the print #8 rev B and replaced it with rev C. I think anyone that has got that far with the build can merely do as you suggested and norrow up the con-rod.

One thing I found with my engine is that the standard o-ring does not last very long. It may be that I don't have a highly polished cylinder bore but I think maybe it is more of a heat problem than a wear problem. The guy I buy my o-rings from ordered some Viton rings for me. They will stand 400 degrees vs the 200+ of standard rings. So far they seem to make the difference. I ended up with 30 of them. I will throw a few in an envelope & send them to you. I still have your address.

Greg, if you will PM me your mailing address, I will send some springs to you. I have quite a few of the very light ones. As I told you before they are light tension springs and I stretch them out to make compression springs out of them. Then cut them to length so that the free length and the compressed length is almost the same for the intake valve. You just need enough pressure to close the valve. The cylinder compression will seal it from leaking.


----------



## GailInNM

Thanks for the Viton O-rings, Arv. I have other sizes of Viton on hand, but was going to order some for this engine soon. I have a Buna-N (nitrile) installed in it right now, but I think you are right about the heat getting to Buna-N as Buna-N has better abrasion resistance.

For reference, Enco, MSC, and McMaster all have them in packages of 100 for about $10. My local seal shop also stocks a full line of them, but it would cost me $10 to drive over there to get them. On line ordering is normally the cheapest for me on most items as I live far from the industrial centers in Albuquerque. 

Thanks for updating the prints. It will make it easier for the next guy to do a build.

Not much will get done on the Tiny for a few days. Have to go play games with the MD's on Monday morning and it will be late in the week before I can get back in the shop safely, although I will probably be on the computer again on Tuesday. 

Gail in NM


----------



## GailInNM

This morning's appointment delayed until after lunch so I have time to post a couple of photos of the previous parts put together. I decided that this engine will look better with a matt finish except for the brass flywheels which have polished rims. The head may get polished also after I look at it when it is built.
Gail in NM


----------



## putputman

That looks great Gail. 

Are you going to run long studs from the head to the frame to hold the cylinder in place?

What have you decided for an ignition system?


----------



## NickG

Looking superb Gail I really like the design of this engine, looks a good one for beginners.

Nick


----------



## GailInNM

Thanks Arv and Nick.
Arv: Thanks for the care package of 0-rings. I am going to use the same ignition system that you used. I bought one a little while back to retrofit an engine I built about 8 or 10 years ago, but I have not gotten around to doing the retrofit yet.  The cylinder will lbe held in place by three 2-56 x 1.5 SHCS, but I have to cut about 1/8 inch off. As usual I have two short and too long screws on hand. 

I finally got back into the shop yesterday and got the head and standoff done. A few changes on each of course. Still the same operating geometry, but a few personal preferences thrown in.

On the head, I changed to 10-40 for the spark plug thread. I rotated the exhaust hole to come out horizontal and threaded it so I can screw in different exhaust systems. It is spotfaced for a locknut. The intake remained the same, but I did add two 0-80 threaded holes to hold a flanged mixer body in place with two 0-80 SHCS. The standoff hole is just a plain 3/32 drilled locating hole and the standoff is held in place by two 0-80 SHCS. All cosmetic and personal preference. It's still Arv's engine geometry with just a different look.

The standoff is flanged and held in place with two screws.
Gail in NM


----------



## metalmad

Hi putput
have just downloaded your plans to see if my poor eyesight will alow me to build one
hope so as it about time i started something new.
anyway 1K to U with thanks from the land of Oz 
Cheers Pete


----------



## putputman

Gail, glad you received the package O.K. I have plenty more if you find you need more. So far I have started my engine several times every day & the o-rings are holding up good. The old buna-n rings would only work for a few days.

I like your stand off. It will give your engine some nice class. Can't wait to see your exhaust system.

I have 0-80 screws and a tap, but have never tried using it. I think 2-56 might be my limit. 

Pete, I think you should go for it. From the conversations I have had with Gail, he has some serious handicap with his eyes also. It certainly doesn't show in his work though. Perhaps he can give you some tips on how to work with that handicap.

Look forward to following your build and will help in any way I can.


----------



## GailInNM

Pete,
Jump on in. Don't let not being able to see all the part details stop you. It may slow you down a bit, a lot sometimes, but if you have some engine building experience the "Tiny" is not too bad. I used some 0-80's because I have worked with them a lot over my life, but 2-56 is the smallest that Arv used on the basic design. And Arv, or I, will help you if you need and detail clarification on the plans. Besides, Arv would probably like for SOMEONE to actually follow his plans. I never was very good a following instructions. 

Arv,
Thanks for the approval on the stand off. The flange was made separate and silver soldered to the post. For anyone who might be interested, the flange is rotated 15 degrees so I made the included angle on ends of the flange 30 degrees so it just is aligned to the flat side of the fork to braze up. I also drilled the holes in the flange a little bit oversize so I can rotate it a bit to align the rocker arm if necessary.

0-80's are not that bad. It's mostly feel. All tapping is done with a spring loaded driver in the mill to make sure the tap is perfectly in line with the hole. I use form taps, so no chips are made to bind up the tap. They are great for blind holes and I seldom use cutting taps except for larger sizes or special sizes. Hole size is more critical, and different, than for cutting taps is the only precaution.

I really like your idea of using the center electrode to support the PTFE insulator while machining. Never thought about doing that. I have a small rotating ball bearing tailstock chuck that I use to support long skinny parts while machining and it will work perfect for that. I am a little worried about drilling the very deep 1/32 hole in the spark plug insulator. My 1/32 drill bits only have .625 of flute so I guess that a lot so very fine peck drilling will be necessary to clear the chips. The drill bits are long enough so that is not a problem. I will find out soon enough. 

The basic body for the spark plug is made, but other than the 0.079 hole being drilled through it I have not done any internal work. I am also making some copper washers to seal the spark plug. I just feel more comfortable with them in place to prevent leakage. OD of 0.265, ID of 0.190 and 0.029 thick. I cut some extra bodys and washers in case I ruin up a body. If I am lucky and don't mess up there are enough that some one can have one if they need it for a Tiny build and I will still have a spare.

No more work until tomorrow. Family get together in a couple of hours that will wipe out the rest of the day. It will be fun however with 3 of the 4 grandkids there.

Gail in NM


Gail in NM


----------



## metalmad

Hi gail and putput 
i hope start getting some aliminium this week and make a start soon.
It will be fun to make I recon.
cheers from oz 
Pete


----------



## putputman

Looking forward to watching your build Pete. Glad you decided to go ahead with the project. ;D


----------



## GailInNM

A little more done. The valves, springs, valve keepers, rocker arm, pivot pins and push rod finished up and installed. A head gasket was fitted made out of 0.007 PTFE. Fair compression bounce when spinning over the flywheel so I think the valves are seating OK. First photo is from the bottom of the engine. Spark plug body is in place but no finished spark plug done yet. Still to go is the fuel system and ignition system plus a lot of details.

Gail in NM


----------



## kustomkb

Very sharp Gail!

Super work!


----------



## NickG

Yes, really nice gail it's a beauty.

Nick


----------



## SAM in LA

Gail,

Looks really good.

The color of the brass is a nice contrast to the other materials.

SAM


----------



## Maryak

Gail,

Another beauty coming along. :bow:

Best Regards
Bob


----------



## Paolo

My compliments...very nice work.... :bow: :bow: I'm thinking to build one of this....
Best regards
Paolo


----------



## GailInNM

Kevin, Nick, Sam, Bob and Paolo: Thanks so much for following along. Sorry it's been a while since I posted. I had some shop maintenance to perform and while I was at it I made up some machine tool accessories that I have been trying to get to for some time. Then with spring here rose pruning and other outdoor spring shores wait for no engine. 

But a little bit of progress has been made with the fuel system now complete and ready for installation. 
Gail in NM


----------



## Maryak

GailInNM  said:
			
		

> Then with spring here rose pruning and other outdoor spring shores wait for no engine.



Interesting - just an aside, we, (she says, I cut), prune our roses towards the end of June, the 1st month of our winter.

Best Regards
Bob


----------



## kcmillin

WOW. That is one nice engine. I think I found my next project. Thanks guys.

kel

ps. is Acetal the same thing as nylon?


----------



## SAM in LA

GailInNM  said:
			
		

> Kevin, Nick, Sam, Bob and Paolo: Thanks so much for following along. Sorry it's been a while since I posted.
> 
> But a little bit of progress has been made with the fuel system now complete and ready for installation.
> Gail in NM


Gail, I have a hard enough time making one part the size of a penny. You have an assembly of seven parts the size of a penny. 
SAM


----------



## putputman

Gail, I like the way you added the mounting plate on the carb. Looks like some more 0-80 screws. 

My guess is we will be hearing some noise coming out of Tiny pretty soon.


----------



## metalmad

Hi putput 
I finerly got some time in the shed and started on the case oh the Tiny
but could u please give me a pointer on the .030 oil hole, is it just cylinder oiling or guden pin oiling anyway i borrowed the wifes camera again to show u a pic


----------



## putputman

Pete, good start. Once the main frame is done you get the feeling your well on your way.

The oil hole is just to lubricate the cylinder so the o-ring slides easier. I also use a little Marvel's Mystery Oil mixed in with the gas.
A drop or two of oil on the guden pin once in awhile is all that is necessary.

Keep the photos coming.


----------



## metalmad

Hi putput
not getting much work over the Easter break so i did a little more on the "Tiny"
I only had the material for the flywheels so started with what I have,
(In between Beers of course)
cheers Pete.


----------



## metalmad

opps


----------



## skeeter

Hi, PUT PUT. I just wanted to thank you for posting your build and above all the plans. I look forward to building this engine soon. 
Thanks
skeeter ;D


----------



## GailInNM

I have been out of the shop for the last three months. Not by choice, but some times life gets in the way.

The only progress has been to get the spark plug built. My plug differs from Arv's in two ways. First the thread was changed to 10-40 as opposed to his 10-32. Just a matter of personal preference. Second, I drilled a 0-80 x 1/8 screw to take the electrode wire and soldered it to the electrode to make the plug wire connection.

 Hopefully I will be able to get the "Tiny" finished up in the next month. Not too much left.

Gail in NM


----------



## putputman

Gail, I certainly hope things start going your way soon. I really miss your attention to details on your engines.

I like the way you provided for the wire connection. You sure must feel comfortable with those 0-80 threads. I still have not gone that small on anything.

What type of end do you have on your spark plug to provide the spark gap?

I haven't seen any activity from Pete on his Tiny I.C. lately. I hope he is still working on it.


----------



## kcmillin

Hello Arv. I thought this question should be asked on this thread.

I started to make the cylinder. I do not have a .375 reamer so I bored it out with a .379 reamer I found, and then lapped it to .380 using an acetal rod and lapping compound. I though everything was well, until I remembered the O-Ring for the piston is store bought and the ID of the cylinder has to match this. 

My question is weather or not I can make a piston ring, or even lap the piston to fit this bore? I assume its to small to make a steel piston ring. Or would 5 thou over be OK for the O-ring. (I still have not bought any o-rings, although I may have one that will work)

Did you try anything different before coming up with the o-ring Idea?

What did you use to make the bore? I can never get a good finish with a reamer.

Kel


----------



## putputman

Hello Kel,

To answer the last question first, I always bore my cylinders on the mill, if they fit, or on the lathe. Normally I can get a decent finish that requires a minimum of lapping. If I am going to use o-rings, I try to get a smoother bore than if I use metal rings.

When using o-rings, use Viton material as it will stand a much higher heat than Buna-N, which is what most hard ware store rings are made of. If you will PM me your mailing address, I'll will send you a couple Viton rings that you can try. I think you should be able to get by with the oversize condition. 

If you haven't got too much work into the cylinder, you might want to start over. The one advantage with the Tiny I.C. is that you haven't got a lot of material involved in any of the pieces.

To answer your question about the legnth of the intake valve, from another thread, the only requirement is that it is enough shorter than the exhaust valve so it clears the rocker arm.


----------



## NickG

Kel,

I was thinking maybe you could cut the groove in the piston shallower so the o-ring is stretched slightly over it's diameter, giving a larger od? Just a thought, you could do that by just trying the cylinder over it and taking further skims until you get an acceptable fit?

Just a thought anyway.

Nick


----------



## kcmillin

Arv, thanks for the info on the bore. I am a little weary about boring such a small hole, hence the use of the wrong size reamer. Perhaps I should give it a go. I have plenty of 1" Steel to practice. (I am going with the air cooled version that Gail came up with, with a fan perhaps. For long run Times)

Thank you for the offer of the O-rings. I do plan on expanding your design in the future to a multiple cylinder version. So I will probably be getting a shipment in.

Is there any reason I couldn't make it a "Ringless" engine, by making the piston a perfect fit. I have never done this before either. This is my first IC engine. Would I need something better than aluminum to do this?

Nick, I did think about that. But the plans call for a groove to be deeper than the o-ring. Im not positive on the correct setup for o-ring piston rings. Perhaps Arv can shed some light on this.  


Kel


----------



## jim hay

Kcmillin
   You might try one wrap of two or three thou brass shim stock under your o ring to just bring it in contact with the cylinder wall and no more, you do not want to make the o ring drag, also allow a little vertical freedom so pressure on the compression and intake stroke can get behind the ring and effect a seal. Hope this helps in the thinking room. Regards  Jim Hay


----------



## lee9966

Personally for a .005 difference I would, as someone suggested, cut the o-ring groove a few thousandths shallower. Its .0025 difference where the o-ring sits, I would guess it would work just fine even though it is a small diameter.

Just my thoughts. Keep in mind I rarely have any clue as to what I am doing 8)


----------



## GailInNM

Kel,
You are kind of at the mercy of the oring manufacturer about the oring working the the oversize bore. The allowable tolerance on orings is kind of loose with tolerances based on both the ID and the the cross section diameter. If you take the tolerances to the lowest limit the oring will not work in Arv's engine. His design is based on the nominal size of the orings. Fortunately, most manufacturers hold the tolerances much closer to the nominal size and seldom go below the nominal size. However, using the nominal size, 0.379 is the largest size bore that would seal using that oring. I think that most of the orings actually end up a little bit larger than the nominal size so it would probably work at 0.380 with most orings. About all you can do is make up a sample piston and try it. 

As far as a ringless engine goes, it will work fine. It is a little more demanding to machine as the lapping has to be done carefully to get the proper fit.  Aluminum will NOT work for the piston however. For a lapped piston/cylinder to work well the materials need to have a similar coefficient of expansion. If an aluminum piston is used in a steel cylinder it will have to be loose when cold or it will seize when the engine warms up. This makes for hard starting. That would not make a good wear combination either.

I prefer to us a cast iron piston in a steel cylinder or better yet a cast iron piston in a cast iron cylinder. These combinations both are very tolerant of poor lubrication and the steel and cast iron have a similar expansion rates. I have used 12L14 and cast iron on a number of engines and it has been frequently used on commercial model aircraft engines. 

Gail in NM


----------



## GailInNM

Arv,
I just did a plain surface discharge for the business end of the spark plug. With this low of compression ratio it should work just fine. Just in case, I made a couple of extra bodies that I can assemble in different ways or have a spare plug.

0-80 threads quit being a problem some 30 or so years ago, although with the eye situation I have to use at least a 3 power hood to see what I am doing in recent years. I still use a few 00-90 and 1mm screws, but not as many as I did a few years ago. For this spark plug all I did was to use a commercial hex head 0-80 x 1/8 brass screw. I chucked on the thread with a collet and thinned down the heat to about half thickness and drilled 1/32 all the way through. 

Gail in NM


----------



## kcmillin

I have yet another slight variation of the frame and cylinder.

This version of the Tiny IC will be an all aluminum frame and cooling fins, with a steel cylinder pressed in like the plans call for. 

I am making the cylinder to the plans, however the OD of the cylinder in between the .469 and .500 will be a tight sliding fit. This is to ensure good heat transfer from the cylinder to the frame.











I needed to make a half round spot on the frame behind the cylinder. I decided to do this while the frame was in the lathe for the boring procedure.

I put my spindle crank in and proceeded to use hand power to cut the two corners round. It was surprisingly easy and went quite fast.

Here is a short vid of that process.
<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/2jfCQTZtbh8&amp;hl=en_US&amp;fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/2jfCQTZtbh8&amp;hl=en_US&amp;fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>

and the result of that.






After milling out the middle and bearing supports this is what I have.





Kel


----------



## SAM in LA

Kel,

That is a nice piece of work.

SAM


----------



## putputman

Wow, a rotary shaper :big: :big: :big:

Clever idea. I never would have thought of that. 

I like your modifications to Tiny I.C. I wonder how many more variations might still be out there.


----------



## kcmillin

I been working on this for the past few weekends and now I am close to a finished product.

This project marks many firsts for me.
1. My first IC
2. My first set of "Real" gears
3. My first carburetor 
4. My first spark plug
5. My first valves 

Here are some pics of the little guy.


















and oh ya, I get her runnin too :big: :big:
Big thanks to all who helped, and especially to Arv for posting the great plans.

<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/Y7jrDJgHQ6c?fs=1&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/Y7jrDJgHQ6c?fs=1&amp;hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>


I am beyond myself with happiness right now. I just accomplished something that 5 years ago I would have thought impossible. 

Make a 4 stroke engine?.......you got to be kiddin me.
 ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

Thats me.


Kel


----------



## 90LX_Notch

Kel,

That's awsome! Great job! Thm: Thm: Thm: Thm: Thm:

Bob


----------



## SAM in LA

Kel,

That's awesome. :bow:

I like your starter.

Do you have any idea what RPM you are running at?

Good job.

SAM


----------



## GailInNM

That is great Kel. And fast and quality build also.
 Thm: Thm: Thm:
Gail in NM


----------



## zeeprogrammer

Very cool Kel.
I haven't been too much into I.C. but that sure makes me what to build one.


----------



## ozzie46

Great job Kel. Sounds like bee.

  Ron


----------



## putputman

Great job Kel. :bow: :bow: :bow: :bow: :bow: :bow:
You built that in record time. I have been following your thread on bevel gears and I thought you quit on the Tiny I.C. 

When engines and details get that small, everything gets more critical when it comes to the valves, fuel mixer, timing etc.. You really nailed it. You should be able to tackle just about any of the larger I.C. engines.


----------



## kcmillin

Thanks Bob, Sam, Gail, Zee, Ron, and Arv.

Sam, From what my shoddy tach says it is running about 6000 RPM. But that could be off??

Arv, I have been silently working on this. The post on the bevel gears is for future projects. Possibly including a mutli-cylinder version of this one. 

For those who are interested, My carb is somewhat substandard. The tiny hole for the fuel is drilled to deep, about .030" past the cross hole in the spray bar. This is causing some issues, also the intake spring is incredibly picky. 

I made a mix of denatured alcohol and colaman camping fuel, with a little bit of tapping oil for lube.

I ran two full tanks through it, about an hour straight, and it never got above 150 degrees. Shell run all day. as long as I am there to mess with it :big:

I would just like to say thanks to all on this website. 7 months ago I had only built a couple air engines and one stirling over a 4 year period. When I finally got the internet last January I found HMEM. Since then I have built 4 flame eaters, one steam wobbler, and this, my first IC. I owe all of this to HMEM and its wonderful members. Without you guys I would still be in the stone age of milling. 

Thank you Thank You Thank You Thank You.

Sincerely

Kelly C. Kubischta


----------



## gbritnell

Hi Kel,
Great job on your little engine. That thing really purrs along. Now that you have accomplished most of the machining tasks in building one what is your next project?
gbritnell


----------



## bearcar1

Kelly, all of us should be thanking you for allowing us to travel along with you on these journeys. To have progressed in experience in such a short length of time is quite the accomplishment. Your 'Tiny' is a real beauty, (by the way, don't turn your head or blink, it will stop running ;D) BRAVO! to you I say, nicely done. So, what's next? ???


BC1
Jim


----------



## kcmillin

Thanks Gbritnell and Jim, your kind words are really appreciated.


Hmmmm, whats next huh?

Perhaps a multi cylinder version of the "Tiny IC" with a cam actuated intake valve and distributer. I'm still brainstorming. I am on a "High" right now from getting this going, my mind is racing.

Perhaps some suggestions? 

Kel


----------



## kustomkb

Awesome job Kel!!

I'm looking forward to your next build, A twin would definitely be pretty cool.


----------



## dsquire

Kel

Congratulations Kel on a fine engine. It is always nice to see that big grin when a new engine fires up for the first time, Even nicer if it's your first IC. Be proud and enjoy the moment, you've earned it Kel. :bow: :bow:

Cheers 

Don


----------



## Maryak

Kel,

I think you should call it Mighty Mouse : Great Job. :bow:

Best Regards
Bob


----------



## steamer

Nice looking Engine Kel!

Very Smooooooooooooth!  ;D

Congratulations on all the "firsts"!

Dave


----------



## kcmillin

Thanks, Kevin, Don, Bob, and Dave!!

I Still need to work the kinks out of the little guy. 

How long should I expect the spark plug to last?

 I have run the engine for about 12 hours so far. I am having trouble with the spark shorting out onto the top of the head. I assume this is happening because the spark plug has high resistance or something. I have cleaned it a bunch, and shortened the gap. This works for a bit but then it shorts out again.

Kel


----------



## kcmillin

In addition to running the engine, I took some high speed videos as well.

This one is very interesting. 

If you look at the smaller spring under the blue spring, you can see it vibrate when it opens. I would think this is the ideal opening characteristics, or normal. Either way my theory is the vibrating of the intake valve helps atomize the fuel entering the cylinder.

You thought are welcome.

http://www.youtube.com/v/tFY8oTB1z2E?fs=1&amp;hl=en_US

Kel


----------



## GailInNM

Kel,
That high speed video really tells it all about the inlet valve. Neat.

I am still plugging away at my Tiny. Just a little bit at a time. Just finished is the exhaust. What would a farm type engine be with out an exhaust rain flap? 

Gail in NM


----------



## kustomkb

Cool Gail!

That'll be fun to see bobbin' up and down.


----------



## kcmillin

That is awesome!

Your sure good at working in miniature.

Kel


----------



## dreeves

Here is my Upshur Farm engine with its weather flap popping around
http://www.youtube.com/v/Rp7UMv6QkXU&hl=en&fs=1


----------



## putputman

That is really neat Gail. You sure have a way with miniature details.


----------



## kcmillin

I have made a few mods to the carburetor. 

I made it a bit longer, and wider.

I made the mixer body out of 1/4 inch hex brass instead of 3/16 square. 

I throttled it by drilling and reaming an 1/8 inch cross hole behind the spraybar in the mixer body. I then made a brass "Butterfly" by drilling a 3/32 hole through an 1/8 inch brass rod, and threading it 2-56 on one end for a nut to hold it in place. 

The spraybar is pretty much the same, but it is made longer to fit the 1/4 inch hex brass.

Here are some pics.

















And what would it be without a video.

<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/SCHjnQPrvls?fs=1&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/SCHjnQPrvls?fs=1&amp;hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>


Oh ya, I took her apart and found some sweet sweet evidence that it is not just my imagination the engine is running.


REAL LIFE CARBON DEPOSITES, WOOOO HOOOOOO.!!!!!!!!!!!










Well thats what I've been up to.

Kel


----------



## zeeprogrammer

kcmillin  said:
			
		

> Oh ya, I took her apart and found some sweet sweet evidence that it is not just my imagination the engine is running.



Very cool Kel.

Yeah...like a kid coming in dirty...meant you were playing. :big:


----------



## putputman

Sounds like it is very effective Kel. I'll look at mine to see if I have enough room to try that.


----------



## kcmillin

Arv, I had to make a 3/8 inch "Riser" base for the engine, so I could get my finger on the end of the card for choking it when starting. 

Kel


----------



## jim hay

On my rendition of Arvs Tiny I take a piece of tubing and put a little pressure in the fuel tank to prime the engine if it has been setting for a length of time which is easier than trying to choke it. Once that is done it is good to go for the rest of the day or whatever. I also use a battery powered Dremel with a 5/8 diameter '0' ring tire on a wheel which makes starting a breeze, just my take on it.
   Regards   Jim Hay


----------



## putputman

Hi Jim, that's one little trick you never told me about. 

Did you make it to LeSueur this year?


----------



## NickG

Fantastic!!! Well done Kel, can't believe how freely it revs, it runs spot on. :bow:


----------



## NickG

PS design is a great credit to Putputman too :bow:


----------



## GailInNM

Another TINY running. First run about a hour ago. Still lots of tweaking to do.
Gail in NM

[ame]http://www.youtube.com/watch?v=MvDkr2UMTSY[/ame]


----------



## putputman

SWEET :bow: :bow: :bow: 
That is a gorgeous engine Gail. That exhaust cap is really getting a work out.


----------



## SAM in LA

Gail,

Nice engine. The exhaust cap is a nice touch. 

SAM


----------



## kcmillin

Awesome Job Gail. Thm: Thm:

The whole thing looks great!

 I love the exhaust flap. 

Kel


----------



## bearcar1

s w e e t i n d e e d! Thm:

Great job.


BC1
Jim


----------



## dsquire

Gail

That is one nice little running engine. The rain drops are going to have to be pretty quick and have their timing just right if they have any hope of raining on your parade. Thanks for showing it to us all. :bow: :bow:

Cheers 

Don


----------



## rudydubya

Really nice Gail. Very well done. Another inspiring build.  :bow:

Rudy


----------



## lee9966

Very nice Gail. What inspired the exhaust cap? I really like it as it adds more movement for interest.

I am about halfway through building one of these (thanks putputman!)


Lee


----------



## kustomkb

Very nicely done Gail!

Another sweet little runner.


----------



## NickG

Wow - fantastic! :bow:


----------



## GailInNM

Arv, Sam, Kel, Jim, Don, Rudy, Lee, Kevin and Nick. 
Thank you all for the kind comments. 

Arv, Special thanks to you for publishing the original plans. I hope you don't mind all the liberties I took in changing things to suit my personal preferences. 

Kel, I will be doing some carburetor experiments a little later. I appreciate your postings in this area.

Lee, I hope yours runs well as the three that I know of that are running. I have faith that it will. 

Some of the changes I made are:
1. Most obvious is air cooling vs water cooling.
2. Exhaust comes out from head at the horizontal. This is mostly because I wanted to have a vertical pipe for the exhaust flap and am too lazy to make an angle elbow other than at 90 degrees.
3. Taper lock hubs for the flywheels, just because I like them.
4. Extended fuel filler and vent pipes for easier access.
5. Extended the crankshaft on the back side for power take off and a knurled finger
starting knob. 
6. Spoked flywheels.

Glad every one likes the exhaust flap. It's origin can be traced back 60+ years or so to my grandparents farm. One of my fond memories of that era was the jingle of the exhaust flap on the old, even then, Ford tractor at idle. Well, this one doesn't jingle but I can fill the sound in with my mind as I watch it flapping . Not original is the bent over rusty nail used as a hinge pin. They also had a farm engine that did not get used much, but it had a rusty nail hinge pin.

I now have about 5 hours of running time on "Tiny". I have been running on a 100:1 mix of Coleman fuel (Naphtha) and 50:1 two stroke oil. I have pulled the cylinder off and there is trace oil on and around the o-ring so the mix seems adequate. The fuel tank holds just shy of 10cc of fuel. My sustained runs have been at low RPM and a full tank runs about 1 hour 10 minutes. This was at 1500 RPM which is about as low a speed that it runs reliably. RPM was measured with a contact tachometer and there is enough torque at that speed that I can not hear any difference in speed when I take the measurement.

Arv mentioned that his engine heats up quickly. Mine does also. When running at high RPM the carb heats up enough that I get a vapor lock after about 3 to 5 minutes. This may be because I bolted my fuel mixer to the cylinder head and have more heat transfer to it.

The needle valve is very sensitive. I have reworked it to a system similar to that I have used on butane regulators on gauge 1 locomotives, but I have not tried it yet. 

I am currently drawing an intake manifold to go between the fuel mixer and cylinder head. I will be placing the fuel mixer horizontal coming out under the exhaust push rod. This is to reduce the heat transfer from the head to the mixer and to allow the mixer to be removed without having to remove the head or removing the engine from the mounting base. That way I can play with fuel mixers or a carburetor easily. Actually I have what I want drawn but now I have to redraw it into something that I can actually make.

Thanks for the interest. I will post photos and more info as things progress.
Gail in NM


----------



## GailInNM

The intake manifold has been built and installed. It is not real neat in that it has two 90 degree bends in it, but at the speed the Tiny runs it should not make a difference. I have enough insulation in it to keep the fuel mixer cool enough that Tiny will run at full RPM with out having any vapor lock problem like I was having. In addition to the extended manifold with cooling fins on it, there are two 0.006 vegetable fiber gaskets in the joints. I also now have a side draft fuel mixer so it is easy to change out when I want to play. 
Attached photos probably tell all. 4 machined parts all silver brazed into one assembly with lots of filing work.
Gail in NM


----------



## GailInNM

The time has come to put the Tiny project to bed, at least for a while. I still want to build a carb for it, but not right now. 
Tiny now has about 11 hours on it. Fuel consumption is about 10cc per hour. Just using the mixture control to adjust RPM the speed range is from about 1300 rpm to 4400 rpm. A few recent changes have been to redo the exhaust flap. It was sticking open part of time so the travel was limited. Compression ratio was reduced from 5.6:1 to 5.0:1 by changing the head gasket. It just seemed like a good idea since naphtha has an octane rating around 50 to 55. The needle valve was changed to a very shallow taper so full rich to lean is about 3/4 turn where it was about 1/16 turn. Larger knob for fuel adjustment. 

Everything else is just finishing touches.
And yes, I know I misspelled naphtha on the name plate - and no, I am not going to change it.
Thanks for following along and special thanks to Putputman for the inspiration. 
Gail in NM


[ame]http://www.youtube.com/watch?v=mLn7xG8vuPQ[/ame]


----------



## putputman

I like that Gail. It's especially neat that you didn't have to alter your fuel mixer.

I guess I haven't run mine long enough at one time to get it very hot. I don't know if I would have a vapor locking problem or not.

It looks like the manifold would provide the added space to add a throttle like Kel put on his. I think I will give that a try. The way mine is I wouldn't have enough space to increase the length on the fuel mixer body.

WOW! I was just getting ready to post this note when your latest post popped up with the video & photos. You have really got that running great. I can get about 4300 rpm but can not get down as low as yours. Maybe with a throttle I can.

It is a beautiful engine. You have to be very proud of it.


----------



## gmac

Gail;

"And yes, I know I misspelled naphtha on the name plate - and no, I am not going to change it."

I think the errors add character to equipment - and perhaps even humanity. Good on ya...

I like the idea of the info tag on the model - including the operation instructions. I'd say it was clever of you but really I think it was wisdom..... 

Beautiful work. I'm not a fan of "small part" machining but between your model and that of PutPutman I may have been convinced to reconsider....at least for one model...thank you.

Cheers  Garry


----------



## cfellows

Wow, Gail & Kel. These two engines slipped right by me! Very nice looking engines. And they run great! Arv, I think you've started a cult...

Chuck


----------



## rudydubya

Outstanding, Gail.

Regards,
Rudy


----------



## krv3000

HI thats brill


----------



## NickG

Briliant. Good idea with the history / instructions.

 :bow:


----------



## winklmj

Wow...what a little screamer that one is. Good job!


----------



## lee9966

Very nice Gail, it's great to see how everyone adds their own unique touches.

Mine is still coming along, although shop time has been limited. I will probably create a thread with pics once I am done.

Thanks to all of you for the great design and further ideas!

Lee


----------



## GailInNM

Thank you all for the kind comments.

Arv: Adding a carb is in the works for the future. That was another consideration in the manifold design that was influenced by Kel.

Garry and Nick: I have seen too many models that have no information on them after the builder is gone. Many times they have a sad fate. About 10 years ago I started documenting the models I build. Mostly just a name tag, but a lot of them have the plans and construction details in a comb binder for each engine. The binders are stored in the bottom of my display case. I don't have to worry too much about my engines future as my son is interested in engines also and builds steam engines commercially. He is also a member of HMEM.

Lee: Go ahead and post your photos now. A lot of us get sidetracked or otherwise delayed on builds so don't worry about a time frame. Sometimes it takes years, but eventually they get done. I think Arv was ready to give up on me and my Tiny.

A couple of quick additions to Tiny. First is a simple muffler. It just plugs into the exhaust pipe. It just mellows the sound a bit. It can be inserted or removed while the engine is running.










Second is a 3/4 inch diameter knurled starting knob. The polished flywheels make starting a little difficult trying to grip them to start. I had extended the crankshaft to use for this or for a power take off so it was only a few minute job.






******
Now there is bad news and good news. 
The bad news. Tiny QUIT running. I was just humming along at about 2000 RPM and just died. I had run it for a few more hours since my last post and it had about 20 minutes of running on a refilled tank. A quick check showed no sign of compression. Exhaust valve rocker had plenty of clearance. OK. I had been running in on straight naphtha with no oil added. Pulled the cylinder and the o-ring had plenty of oil left. But what did need lube was the intake valve. It was not closing with the light spring. A drop of 10W machine oil and a little exercise restored it to like new condition. 
The good news. After reassembly Tiny took right off. And I am back to 1/2 percent oil in the fuel.

Two minor ignition problems have shown up. As Kel noticed the spark will jump from the plug to the exhaust rocker support. On mine this only happens if I flood the engine. I am going to replace the insulator on the plug with a longer one. The PTFE insulator just presses in so it will only take a short time to repair. This brings me to the second problem. The PTFE works out of the plug body a little bit every few hours of running. Everything keeps running, but the fuel mixture adjustment gets more critical. When I make the new insulator I am gong to cut a couple of shallow grooves in the PTFE so I can get a grip on it with a little high temperature epoxy when I install in into the body. 

Gail in NM


----------



## kustomkb

Wow Gail! That little sucker hum's along beautifully! 

You scared me with your last post but I'm glad you got it sorted and found even more room for improvement.

Well done everybody.


----------



## bearcar1

Gail, that is one well executed little jewel. Very nice.

BC1
Jim


----------



## littlefold

Hi Arv and Gail,
Thanks for taking the time to talk with me about the engine.

I now have all the metal for the build.
I will make my first cut Friday.
With the help of everyone here,I hope to be able to build one.
I think I am going with Gail's air cooled style,it seems it might be a little easier.

I have always lurked in the shadows,so now it's time to try my hand at a real engine.
This will be a first and during the build there will be a lot of firsts.
Arv I did find the gears at a hobby store.That was a worry not being setup to cut gears.
I am going to call S/S Machine & Engineering in the morning to order the CDI ignition.
Thanks to all for this great forum,I look forward to talking and learning.

Tim. ( Alabama--Roll Tide! )


----------



## GailInNM

Glad that your are joining in the fun Tim.
If you need any assistance, there is lots of help is available here from lots of people.
Gail in NM


----------



## littlefold

Gail,
If I can finish with a engine half as nice as yours and Arv's I will be doing ok.
Thanks Arv for the plans and the help.
I hope to talk with you more about the ignition.I going to get the same that you used in your Tiny.
Thanks again to all.
Tim


----------



## putputman

Hi Tim, Welcome to the forum. I'm glad you finally jump in. I think you will really like it here. 
If there is anything we can help you with, just ask.
I hope you can post some photos as you move along on this one.


----------



## littlefold

Hey Arv,
I talked with S/S about the Cdi ignition and the lady that I spoke with was kinda lost.
I told her I would ask some guys that new the type I needed.
So,what type do I need? ???
I thought I would get my Aluminum today but it didn't come today.Shipped it in two boxes.
So as soon as I get it I will make photos of the build.
My dad had a box of old stuff from his working days and found some small blank punches like you used for the valves.They don't look like they are hard steel,am I saying that right?I don't know how to tell if it is or not.
When I get to that point I hope I can use them.Still thinking about the valve cutter??
Thanks for all the help.
Tim


----------



## Cliff

Very niece build it shows a lot of talent read your post and thinking I might like to build one. Could you post the prints again I downloaded the ones in the post but I couldn't find the one that you talked about where the corrections are and there all on one PDF file. Again awesome build Thanks Cliff


----------



## GailInNM

Tim,
Arv and I used the same ignition system. 
Here are the details since they don't have part number on the website.
If you want to use your own batteries and charger they have the same thing for $20 less.
Gail in NM

It is the sixth item down on the left side of this page.
http://www.cncengines.com/ic.html

Complete CDI Ignition system
for many single cylinder engines
up to 12,000 RPM.
Multi cylinder engines with distributor
up to 12,000 sparks per minute.
THIS IS A BOLT ON FOR THE
BRASS MODEL "T" ENGINE
BY DALE DETRICH
INCLUDES:

  1. single spark cdi module
  2. hall sensor and 1/8 dia. X 1/8" long magnet
  3. battery holder with 4 AA - 700 ma NiCad batteries
  4. ON - OFF slide switch with charge jack
  5. overnight wall charger - 110 volt
  6. spark plug wire assembly with flat spark plug clip
  7. ground wire with ring terminal for #6 stud

$100.00


----------



## putputman

Tim, the pin punches I used were called Royal Pins. Don't know if they are even available any more. They are very hard. The problem is that they have a slight seam on the bevel part of the head and unless you have a toolpost grinder to remove that seam, you never get the valve to seal tight. You might be better off to make your valves like Gail did. I'm sure he will provide the information you need to make them.

I have always talked to Roy Sholl at S/S. He is very helpful. I recommend you buy the entire package that Gail suggested. That way you will get fresh batteries & a charger along will all the connectors, wires, & switch. 

Cliff, just hang tight for a day or two. Gail is going to load all my drawing into the download area so they will be easier for everyone to download.
Looking forward to your build also.


----------



## GailInNM

The building package for TINY has been placed int the Downloads section. It is the second item on page 10.
Everything is in a single ZIP file. There are 20 drawings in PDF format and a set of notes also in PDF format. The drawings have all known corrections from the original in them.
About a 2.6 Mb download.
The download can be directly accessed at:
http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item310

Gail in NM


----------



## NickG

Thanks Gail,

I'll file that away, I've always wanted to do an i.c. so it's only a couple of projects down the line! I wanted to do a hit and miss but seeing peoples success with Tiny it might edge it's way to the top, it doesn't cost the earth if I have to do it again!

Nick


----------



## kcmillin

Tim, about the valves.

I made my valves out of 1/4" drill rod. the stem diameter was turned down to .078" instead of .0625". I then cut the angle on the valves and the valve cutter without changing the setup on the lathe. 

I did not get a perfect seal with the valves until I used a tiny dab of fine lapping compound from the hardware store. I put the valve in the head with the spring on it, dabbed on the lapping paste, and twisted the valve back and forth for a few minutes. I then tested the seal by taking a vacuum pump for auto use and applying a vacuum to the backside of the valve. I was satisfied with the fit once it was able to hold a vacuum at 20hg's for about 1 minute.

I also used the same ignition system from S/S. It is really easy to get setup, and works like a champ.

You picked a great engine to make, Although its size may seem intimidating, It is a pretty easy engine to make, and cheap to Re-make if any parts come out less than satisfactory.

Kel


----------



## littlefold

Hey,
Arv,
The pins my dad has looks like drill rod and he called them punch blanks the head is 60 degrees and about 2 inches long.He said they cut them to length and added them to some machine?
Gail,
Thanks for the info.on the Cdi.I saw that one and thought that was it.I'm going to order it tomorrow or Monday.
Kel,
Thanks for the help on the valves.When I get to that point I would like to talk with you more about making them.
I will definitely need the help.
Thanks to all of you for the help.I look forward to building the Tiny with all of your help.
Tim


----------



## gmac

Tim;
When you get to the valves this may help;

http://www.modelenginenews.org/techniques/stepturn.html
http://www.modelenginenews.org/cirrus/valvegear.html#2

Cheers
Garry


----------



## gbritnell

Gail,
I'm sorry I haven't posted sooner. This is an outstanding build and I especially like the instruction panel. I have been concerned with passing along information with my engines and you have solved that for me. 
 As far as making a new Teflon plug, I know that the small diameters are a bugger to cut so why not see if you can get a piece of Corian. It is rigid, will take the temperature and has fairly good electrical qualities.
George


----------



## GailInNM

Thank you George. That is a high compliment coming from you.

The data plate on this engine was done on 3mm thick acrylic that was deep laser engraved and then filled with solid paint. Any modern engraving shop can do what ever you want for a few dollars. Cheapest is if they make the plate out of standard multilayer engraving stock like what is used for name tags. No paint filling is required on that. If you supply a data file that they can work with then you can keep costs down also. The standard for most shops is Correll files, but many can read DXF and DWG files. Just put the cutting lines and the engraving on separate layers or different colors. The cutting kerf width will vary from machine to machine but is typically 0.006 inch. For mounting holes I typically draw the standard clearance size and do not correct for the kerf. So I draw a 0.086 for a 2-56 clearance and the hole will end up about 0.092. I have a small 30 watt laser engraver/cutter and the TINY data plate took about 7 minutes to cut and deep engrave directly out of ACAD 2000. The engraver is treated like a Windows printer with different colors used to set the speed and power of the laser. 

Cutting the Teflon is not a problem. I drill the center electrode wire hole first and insert a music wire in the hole. Arv used a bushing in his tailstock chuck, but I have a small drill chuck that is live with a couple of ball bearings supporting it. I just clamp on the electrode wire size mandrel with the chuck and the Teflon is supported so that it cuts as easy as brass as long as the cutting tool is very sharp and on center. I originally made up the live chuck to support mandrels for winding small diameter spring stock in the lathe, but it has been used for other things far more than spring winding. 

I have Corian and have made larger plugs with it. I was a little concerned about electrical breakdown in this small size. Calculated breakdown for it is about 14kV while the the Teflon calculates out to be about 40 KV. As a rule of thumb I have tried to keep above 20 kV to allow for flooded engine conditions. But, when I turn a new insulator I will make a few out of Corian also to see if it works OK. It probably will be.

Tiny got a little bit hard to start recently. Took about 6 or 8 spins on the finger start knob as opposed to the 2 or 3 that it normally takes. I think it has about 18 hours on it now. I pulled the plug and I could not see the center electrode for all the carbon. The plug was just set up as a surface discharge. Pressing it apart, I cleaned it and then peeled back the Teflon support around the center electrode at about a 45 degree angle and left 15 or 20 thou of the center electrode bare. After reassembly it was a whole new engine. Operating fuel mixture range was almost doubled on the needle valve and rich mixture low speed running was much smoother with less misfiring. I think I will make up a whole new plug and extend the 1/8 diameter tip enough that I can mill away the sides to leave enough of a protrusion to bend over for the ground electrode to make up something that looks more like an automotive spark plug. Maybe these full size plug makers really do know something. It will be a few day before I get to that however as a couple of household projects need my attention in preparation for some model engineering type house guests arriving from out town for a week of intense toy building.

Gail in NM


----------



## Cliff

Thanks


----------



## gbritnell

Hi Gail or Arv,
I have downloaded the plans and notes and have gone through the entire post but I couldn't find what size wire you used for your valve springs. I probably missed it but if not could you post it?
Thanks,
George


----------



## cfellows

I don't typically like to build model engines this small, but there is something about this one that keeps pulling me back. Hmmm, wonder if a hot tube engine this small could be made to work...

Chuck


----------



## putputman

George, I probably didn't post anything on the spring as I used some springs out of my collection. I save every small spring I find and also buy some of those spring assortments you get at the junk stores. 

The exhaust spring can be anything the actuator can operate. The intake spring has to be as light as possible and still moves the valve closed. I rely on the compression against the valve head to really seal the valve. As one old timer told me, "you just need enough spring pressure to keep the flies out".

Hopeful Gail or Kel can give you better information than I did.


----------



## kcmillin

George, I too used a spring I had on hand. I believe it came from an X-Mod R/C car from radio shack. I purchased a package of an assortment of tiny springs. I used the lightest spring, and trimmed it so it was a loose fit with the valve closed. 

I would say the spring wire is between .012 and .018, and about 4-5 coils. I am going to try some guitar strings to make some springs The Deanofid way. 

Shown Here
http://www.homemodelenginemachinist.com/index.php?topic=8253.0

Kel


----------



## GailInNM

George,
My intake spring is 8 turns of 0.009 music wire wound on a 0.078 mandrel. Finished OD is 0.115. Free length was set to provide about 0.05 compression with the valve closed.

My exhaust spring is 8 turns of 0.012 music wire wound on 0.078 mandrel. Finished OD 1s about 0.115 also.
I started off with 0.011 wire, same wind, but changed it as I thought I was getting some valve float at high RPM.

I did not do a post winding heat treat on them.

Arv was kind enough to send me two of the springs he used for the intake. It was an extension spring that he then stretched out. I measured it at 0.012 wire size and 0.152 OD. I ended up not using them as I wanted to use an1/8 spring keeper so they were larger in diameter than I wanted. 

If your, or any other Tiny builder needs some wire to make the springs, I have 1 pound coils of those sizes and other sizes near them that I bought at machine shop auction that was going out of business 20 years ago. I have not used more than a few percent of any of them so I have enought for many lifetimes of building toys. I will be l glad to spool off 10 or 20 feet and drop them in an envelope and mail to people with US addresses N/C.

Gail in NM


----------



## littlefold

Gail,
Do you buy your metal online?
If you do who do you use?
I'm having some problems with my online metal supplier.
It has taken a long time to ship.
If anyone can give me a good source I would appreciate it.
Thanks guys.
Tim


----------



## gbritnell

Hi Gail,
Thanks for the offer. I dropped you a note.
George


----------



## GailInNM

Tim,
You asked about metal suppliers a few days ago. I have built up a good stock over the years so don't have to order too much any more. If I need a foot, I normally end up ordering 3 feet so I have some on hand.

If I just need a little bit of common 360 brass, 6061 Aluminum, or CRS, I have a Metal Supermarket about 10 miles away. They are expensive but no shipping and I can have it today. They don't have mush in the way of my preferred materials. I like 12l14 and 1144 steel. 2024 and 7075 Alum for conrods and pistons and the like.

When I do order however, I shop around a little bit as prices vary wildly between suppliers, and some have cutting charges and some don't. Others get to you on shipping. So I do comparison shopping.

My favorite on line suppliers are:
http://www.speedymetals.com/
Best for cast iron and have a good supply of specialty metals. One of the few online places that have cast iron below 1 inch diameter. Also have small diameter 12L14 for building small toys. Quick shipping.

http://www.onlinemetals.com/index.cfm
Quick shipping, but watch out for their cutting charges. They have a weird way of calculating them.

http://www.metalexpress.net
I have used them a couple of times, but recently thier prices have seemed to increase more than average. Multiple warehouses and not all of them stock everything. Just have to check that everything is coming out of the same warehouse to keep shipping costs down.

Some times you can get good buys on ebay for screw machine remnants, but most of the commercial suppliers of stock sizes on ebay are expensive. 

Everything changes from week to week, so you have to check them all out.

Gail in NM


----------



## putputman

Tim, another place to buy material, tools, etc. is McMaster Carr. I consider them a very good supplier and buy most of my stuff from them. They are not cheap, but they handle good stuff. 

The biggest problem I have with them is they use UPS for shipping and shipping can kill you. I hold off on my orders until I have enough to spread the shipping cost over more material & tools.

They also have one of the better catalog Webb sites. It is easy to navigate & zero in on what you are looking for. 

When you start getting near the end of your build, I have some extra springs, plastic tubing, & Viton o-rings I can send you. Just let me know when you want them.


----------



## stevehuckss396

putputman  said:
			
		

> The biggest problem I have with them is they use UPS for shipping and shipping can kill you. I hold off on my orders until I have enough to spread the shipping cost over more material & tools.



I have always found MCMC to be one of the more reasonable on shipping. The shipping is not figured on any orders. After you order you are charged actual shipping cost and is usually less than I figured.


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## gbritnell

Being that Arv, Kel and Gail have posted there Tinys in one thread I hope that they won't be put off by me adding some of my build. If this thread is getting too crowded I can start another with no problem. 
Anyway for those following this thread there has been a great deal of interest shown by Chuck, myself and a few others so being that I like to build small this was right up my alley.
Here's my first part, the cylinder head. I went with iron for the material. I had read that there had been a little bit of a problem with arcing from the plug to the rocker arm/post so I changed the angle of the plug port. I am going with an 8-32 plug so the thread was also changed. For the intake and exhaust ports I threaded them 8-32 also. This way I can make my inlet and exhaust pipes and thread them into the head. And last but not least I added about .047 material to what would be valve guide stem extensions. Having seen the videos of the others running I don't know that this is a necessary change but if they add too much friction I can always cut them off. When I turned the head I left extra stock and then spun the bosses on my rotary table. 
Ok. on with the pictures.
George


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## kcmillin

Nice Work George. 

I think you picked the perfect place to post your pics. This thread is turning out to be an incredible wealth of knowledge, and should make making the engine easier for others, plus a plethora of variations and improvements. I would imagine that Arv is one proud pappy.

I love the extensions for the valve guides. 

Probably a good choice too, My exhaust valve guide is wearing from the rocker arms sideways influence. I am going to make roller rockers for my inline to hinder this from happening.

Kel


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## cfellows

You're off to a great start, George. Can't wait to see how your flavor turns out, given the unbelievable work you've done on other engines.

Chuck


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## GailInNM

Come on in George. Arv is throwing a great theme party. 
Looking good.
Gail in NM


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## putputman

Glad to have you on board George. It is unreal how many variations can be made in a 3/8 diameter bore. Looking forward to watching this build.

I'll bet Chuck is trying to figure out how he can use bearing balls & magnets in his build. He is a master with those items.


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## NickG

This is a great thread, will be the first place I look when building my first i.c. thanks to all :bow:


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## gbritnell

I got some more parts made this morning, the piston, pin and connecting rod. I went with bronze for the rod so it would serve as a good bearing surface. I cut a little recess in both sides of the rod to make up for the weight of it versus an aluminum rod. I also went with 1-72 screws to hold the rod cap on which will offset the weight. 
gbritnell


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## littlefold

Thanks guys,I have placed my order.

That looks great Gbrit. 
When you go in from the side for the spark plug do you first drill a straight hole all the way through?Then drill from the side to meet the hole?I guess you would just plug the top hole?
I am trying to get this.
Looks great so far.

Tim


----------



## gbritnell

Hi Tim, 
 I'm not quite sure what you're asking but here's what I did for my spark plug hole. 
 As I mentioned, one of the fellows said that they go a little arcing from the plug to the rocker assembly and looking at the pictures I can see why, the plug is very close. 
 I looked at the original design and laid it out in my CAD program. I changed the port that enters from the combustion chamber side so that it has 5* on it. I went in about .160 from the shoulder of the drill. I then set up the head so that I could come in from the outside and indicated it square to the bottom 2 screw holes. I then rotated it 38* from vertical and tilted it back 48*. This gave me a perfect intersection with the first hole. I then counterbored the hole to about .200 dia. until I got a nice flat surface and then tapped it 8-32. 
 If anyone is building 'Tiny' and would like a drawing of this revision please let me know and I would be glad to provide it.
George


----------



## Metal Butcher

Hi George, I see that you are off-and-running. I can't wait to see your version in person!

I really like that you're building a project that I can relate to and accomplish myself in the near future. 

Hi Tim, Are your referring to the optional spark plug side-entry shown in the full size plans? I looked at the "plugging" idea and will probably drill from the bottom of the head (combustion chamber) to intersect with the threaded side entry location. It should work, although "plugging" is not at all difficult. I prefer the idea of a side location for the plug on the full size version. Plenty of room that way with out being near at the busy top end of the head. On the 'Tiny' version I'll likely play follow the Leaders!

-MB


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## gbritnell

Well here's the latest update. I have both valves made an lapped into the head. I made one keeper for the exhaust. My valve stems are .062 so the notch for my keeper is .047 diameter. I made the rocker post with my twist on the design and I made my rocker arm. Although the pushrod is adjustable I have an 0-80 adjuster screw on the tip of the rocker. I should be able to finish up the other keeper and the springs tomorrow. That will finish up the head.
A special thanks goes out to Gail for the spring wire he so generously supplied. I got it in today's mail.
I won't get any more done till Monday as my buddies and I are off dirt biking over the weekend. The weather is supposed to be in the low 80's. I'll take it while I can. 
George


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## NickG

Brilliant stuff there George. 

I haven't studied the drawings properly for this yet but does anybody think there is scope to add a governor to flywheel and make it hit & miss?

Nick


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## GailInNM

Very nice George. I think relocating the spark plug as you did is a good idea. In all fairness however, the only time I had an arc over to the rocker post was when the plug was fouled with raw fuel in a flooded condition. Naphtha in a much better insulator than air and I was using a surface discharge plug which compounded the problem. It was not all bad either. It gave me a visible and audible indication that I was flooded. After I learned how to adjust the engine, modified the plug and made the fuel mixer less sensitive there was no more problem. Glad you are able to make use of the wire. I still have a 1/2 mile to a mile of each size here. A one pound coil goes a long way.

Nick: I have done a couple of back of the envelope sketches of a Hit-n-Miss setup. Most practical so far seems to be to use the flywheel on the far side from the cam and put a catch on the cam follower actuated by linkage coming across from the far side. I lso wanted to put an over ride on it so it could be operated in a non H-n-M conventional mode. No drawings, just sketches, but I think it can be done without too much grief. 

Out of town house guest arriving Monday for a week, so nothing will be done next week.

Gail in NM


Gail in NM


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## NickG

Gail,

Thanks for the info, think I will have a closer look at the drawing tonight to see exactly what you mean. Do you think hit n miss would be effective visually pleasing on an engine this small though? Will the flywheels be sufficiently heavy to provide a few revolutions coasting? I can imagine it hitting a lot with not much time between.

Nick


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## cfellows

GailInNM  said:
			
		

> Very nice George. I think relocating the spark plug as you did is a good idea. In all fairness however, the only time I had an arc over to the rocker post was when the plug was fouled with raw fuel in a flooded condition. Naphtha in a much better insulator than air and I was using a surface discharge plug which compounded the problem. It was not all bad either. It gave me a visible and audible indication that I was flooded. After I learned how to adjust the engine, modified the plug and made the fuel mixer less sensitive there was no more problem. Glad you are able to make use of the wire. I still have a 1/2 mile to a mile of each size here. A one pound coil goes a long way.
> 
> ....
> 
> Gail in NM



Gail, how did you make the fuel mixer less sensitive?  Chuck


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## GailInNM

Nick,
I think it will work quite well. When running my TINY at about 2000 rpm, I held the exhaust valve open with my thumb. I am guessing that it took about 10 to 15 revolutions for it to slow down to a point it would still restart when thumb was removed. This would improve if the mixture was leaned out more. There is lots of flywheel mass on this engine as the Tiny is such a small displacement. 

If a little bit of thought is put into the governor arm pivot point VS angle and the spring attachment point, the some hysteresis could be introduced into it to get a higher than normal start hitting to start missing range. If you went too far on this however it would have to hit several times to get back up to RPM so it could start coasting. Would take some playing to get the most pleasing action.

Gail in NM


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## GailInNM

Chuck,
I went through my stock of #10 Sharps sewing needles and found one that measured 0.0195. A #10 is nominal at 0.018 but mine are all oversize. The drilled out the spraybar opening for the needle to 0.020 so the needle would just fit in it. It wont quite shut off the fuel, but with the long taper the small annular opening can be adjusted by withdrawing the needle very precisely for small fuel flows. Fuel flow is small on TINY. I am now up to 40 minutes of run time on 5 cc of fuel with the engine running at about 1800 rpm. I keep reducing the oil in the fuel mix and am now running 0.2 percent which is 1ml to 500ml naphtha. Still plenty of oil collected on the o-ring so it can probably be reduced further. At 40min/5ml that would mean that it should run 500 hours on a gallon of Coleman fuel.

I do want to try Jerry Howell's mixture of 30 percent naphtha to 70 percent methanol alcohol + oil. He claimed it ran much cleaner than straight naphtha and the naphtha addition to the alcohol made ignition easier and more reliable. 

Gail in NM


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## NickG

Gail,

thanks for the reply, good point that the flywheel intertia is quite high compared with the rest of the engine and making some sort of setup that you can play tunes with would be a good idea.

I have 3 projects I really should complete before this but I'd say 2 of them I'm over 50% of the way and am actually working on those so it shouldn't be long. Maybe the turn of the year!

Nick


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## gbritnell

Hi everyone,
Here's the latest update to my 'Tiny'. I have Firefox so I haven't posted in awhile. I switched over to IE to get on line. 
I have the crankcase finished except for final polishing, I'll get to that when I tear everything apart. I made my head competely round and made the crankcase match. I put and angle on the sides of the water hopper and radiused all the corners. I lowered the rail that the main bearings sit in. 
I used round stock for the crank so I left counterweights on it. As fast as this thing runs it might help the balance a little. 
I found out that there is very little clearance between the rod an cylinder sleeve so I had to slightly radius the edges of the rod at the point where it's closest to the sleeve.
Everything is a little oily because I was running it in on the lathe. 
I have the flywheels roughed out and they just need the lightening holes and set screw holes to finish them up. 
This is a fairly easy project and I would encourage anyone thinking about getting into and IC engine to give this one a try. You could even scale it up a little if it's too small for your taste. 
gbritnell


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## gbritnell

I had a request for the revised spark plug hole that I put in my head. I made up a drawing in Autocad and saved it as a PDF file. I am posting it here for anyone who might like to use it. I am going to use a 6-32 plug in my engine. You can still use a 10-32 plug with this configuration but you will just have to make the counterbore large enough to fit that plug. 
britnell 

View attachment TINY HEAD PLUG REVISION.pdf


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## cfellows

Nice work, George. Is the crankcase made out of steel?

Chuck


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## gbritnell

Hi Chuck,
No, the crankcase is made from 6061 aluminum. I have just finished up the flywheels except for final finishing and polishing. I made them from 12L steel. 
George


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## cfellows

Nice work on the flywheels, too. Did you cut those by hand or did you use CNC? What size milling cutter did you use?

Chuck


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## GailInNM

It looks very nice, George. I am looking forward to watching it run.

I had an out of town house guest here for the last week. He is a model engineer, but not normally into IC engines. He and I have worked on joint projects from time to time for many years and get together once or twice a year for a week of toy building. He does not do much machining, but is a wizard with a file and sheet metal. So, while he was here I machined parts for our current project for a few days and he became intrigued with TINY. He played with it for hours and I would occasionally make up a new part for it to try and he would install it and test run. This is a summary of some of the findings plus a little bit of things after he left.

I had been running on naphtha plus 5 percent WD40. We continued with this mix for the first day. On a whim, we mixed up regular gasoline with 5 percent WD40. The first thing noticed was that starting was much easier. Once fuel had filled the fuel line, one revolution with finger over the air intake to choke it and starting routinely became one twist of the hand starting knob. With With naphtha 4 to 5 twists were the norm.  The needle valve also became less sensitive. On naphtha full rich to lean was a half turn. On gasoline it went to 3/4 turn. In addition the cylinder fin temperature dropped about 15 degrees. Fuel consumption dropped a little bit from about 7 minutes per ml on naphtha to 6 minutes on gasoline. 
The biggest down side is the smell of gasoline, but the improvement in performance makes this OK for me.

Looking for further improvement on ease of adjustment, a series of mixer bodies was made up, identical except for the bore. I had been running with the 0.093 hole as specified by Arv. Tubes were tried with holes from 0.073 to 0.098. Performance was definitely degraded at each end of the range, with a slight improvement with 0.082 and 0.086 holes. I settled on a 0.082 hole. All these tests were run on gasoline. Before anyone decides that this is gospel truth for Tiny, keep in mind that I live at almost 6000 feet of elevation and mixers act different up here than at low elevations.

Early in our playing, we did a sustained wide open throttle test. It cooked the Viton o-ring in about 20 minutes. The cylinder fin temperature was reading about 165-170 degrees F as measured with an IR thermometer.
We repeated the test now that the cylinder fin temperatures were lower, about 150-155 deg F. It cooked the o-ring in about 20 minutes the same as before. The o-ring showed no sign of wear in either test, but became hard and would not seal. On low speed running the o-ring holds up fine.

That's about the point we were at when Jim packed up and hit the road for a 10 hour drive home. All told, we used about 30 ml of naphtha based fuel and 120 ml of gasoline based fuel through TINY. That's about 14 to 15 hours of running bringing the total at that time to about 45 hours running time on TINY. Except for the first 10 or so hours using a PTFE insulated plug, a Corian insulated plug has been used. Thanks to George for getting me to try it is this small a size. Still looks good and works well. I have pulled it a couple of times for inspection and other than cleaning off the oil and soot build up from running rich no maintenance has been needed on it. It was not needed then, but since it was out it was cleaned. I used a 0.020 gap most of the time, but increased it to 0.025 the last time I had it out.  

The saga continues with what has been done since Jim left. That's for another post.

Gail in NM


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## gbritnell

Hi Chuck,
Nope, just plain old milling and hand work. I drilled the upper corners with a .125 drill and the base of the spokes with a .187 drill. The tangent angle came out to just under 2*. I went in with a .125 endmill and cut the remaining stock out. I debated about putting a full radius on the spokes but I'll leave that for another day. 
I got them drilled and tapped this afternoon so they're finished.
I had roughed out some hob type cutters awhile back, one 36 DP, one 42 DP and one 48 DP. I fluted them, cleaned up the burrs and hardened them so that I could cut the gears for 'Tiny' and have the others finished for the transmission that I'm going to build. 
Gail,
I have never used anything but regular (86) pump gas in my engines. The smell isn't pleasing but I have never had any problems with performance. I thank you for your input on the carb. Being that I don't live at the same elevation as you I should be able to use the smaller diameter with no problem. 
George


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## putputman

Gail, I'm curious as how you change the gap on your plugs. How are they built.

And George, you are using 6-32 thread on your plug. Can you post your design on that plug. Do you just allow the spark to jump from the electrode to the bore diameter in the head?


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## kcmillin

Gail, I have had to replace the cam due to wear. I am curious what your cam looks like after 45+ hours of running. 

I am using brass for the cam and steel for the follower so it is no surprise to me that mine is wearing down. What materials did you use?

Kel


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## stevehuckss396

kcmillin  said:
			
		

> I am using brass for the cam and steel for the follower so it is no surprise to me that mine is wearing down. What materials did you use?



For the Peewee I used O1 drill rod for the cam and 12L14 for the followers.


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## kcmillin

Thanks Steve, my current project will use that combo. 

Did you harden the cam? Is this necessary? If so, did you have to accommodate for shrinkage? Also, my valves are made out of drill rod. I made them to final dimensions. If I harden them (which I have no experience or equipment to do) would they be scrap?

Kel


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## gbritnell

Hi Arv,
Here's a PDF of the spark plug. I haven't made it yet but I have made 6-32's in the past and they worked fine.
George 

View attachment TINY SPARK PLUG.pdf


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## gbritnell

Hi Kel,
The valves don't need to be hardened. If you did I'm afraid they would warp. The only way to have hardened valves is to leave them oversized, harden them and then grind but like I said it's not necessary. 
George


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## GailInNM

Arv,
My current spark plug is made with Corian at Georges suggestion. I will describe it in detail in a post a little later along with some photos. I made several changes, but to answer your immediate question the ground electrode is just like a standard automotive plug. It was machined on to the body blank as a straight protrusion and then bent over at assembly time. So it's just a matter of tweaking with a feeler gauge to set the gap. 

Kel,
I have no visible wear on either the cam or cam follower. I used 12L14 steel for the cam and 2024 alum for the follower. The follower is polished a little bit, but the cam still shows machining marks because I did not polish it like I should have. The only wear on the engine that I know of is there is a little extra clearance on con rod big end. Con rod is 2024 alum and crankshaft is 12L14.

Gail in NM


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## kcmillin

Gail, Thanks for your answer.

I had the same problem with the connecting rod. I ran her hard a fast for a few tanks, cranked up the timing and held on! Well, needless to say the con rod journal was hashed. Instead of making a new connecting rod I drilled the hole a few thou oversize and then made a bronze bushing. I made it on the lathe then split it in one spot and stretched it over the con rod journal. The split's irregularities keep it in place by gripping on the aluminum connecting rod. Since then I have ran it without trouble and the con rod has no noticeable slop and runs freely. 

I should note that I adjusted the torque on the con rod cap a little tighter each tank for a couple tanks until it seated properly enough to run free with the cap tightened all the way.

I should also note that I used a small side cutters to split the bushing, and did nothing further to it before installation. I am positive there is a better way.

Kel


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## gbritnell

Hi Kel,
The next time you make a split bushing try this.
Take the 2 pieces of the material you are going to use (brass-bronze) and make rectangular strips out of them. Lightly tin one side of each with 50/50 solder. Flux them up and clamp them lightly together. Now heat with a small propane torch until you see the solder squeeze out from the sides. Let cool and clean up any extra solder.
Now put the bar in your 4 jaw chuck and get it on center. Turn the material to your bushing size and part off. Now just heat with the torch until it pops apart. Clean up the solder and mount the bearings. I put a small hole in one half so that I can put a pin in the cap to prevent it from spinning. 
George


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## kcmillin

George, WOW your brimming with good ideas. I like that method very much. 

I should point out that the bushing I made was .005" thick. Would this be to delicate to solder and machine out? I could just make the bearing block hole bigger though.

THANKS!

Kel


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## kcmillin

Since there has been experimentation with fuel for the Tiny I though why not propane.

 Well, I just got the Tiny running on propane. Crudely I might add. I simply held the un-lit propane torch up to the carb and gave her a spin and she took off! I adjusted the speed by turning the knob on the torch. This should only be done outside because there is a lot of propane not getting into the engine. If a properly made LPG delivery system is made then the Tiny will indeed run on propane.

Just though I would add this.

Kel


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## gbritnell

Hi Kel,
I don't think it would work at .005. The thinest wall I've made was about .025.
Well here's today's update. I finished the gears, cut the cam, made the cam follower, the rocker arm clevis and pushrod. It's getting close. I'm going to use a Hall sensor on it and I want to make it so I can adjust the timing a little so I'm going to pull up the Autocad and do a little design and layout. I think I'll make a little bracket that pivots on the crank and mount the Hall on this. The magnet will be mounted on a small disc outboard of the Hall sensor. I should be able to squeeze it in without much trouble. 
George


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## gbritnell

Here's the last 2 pictures of today's set.
George


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## kustomkb

It's looking really nice George. 

Can't wait to see it run. Thanks for your added design input as well.


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## putputman

Looks great George. You sure put out a lot of work in a short time. 

I really like the way you radius all the edges. It gives it a finished look.


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## lee9966

Lots of nice ideas here, and fun to read especially since I am making a Tiny also when I get a few hours here and there.

Gail, thanks for the spring wire, much appreciated.

Kel, propane huh? I put aside the guts of one of those refillable butane barbecue lighters and was thinking of messing around with it on this engine once I get it running.

Thanks all,

Lee


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## gbritnell

Gents,
Here's a couple of updates for today. First is the muffler. I went with a somewhat traditional hit and miss type muffler. The bolts holding it together are 1.0x.25 mm. (.039 dia.) It is spaced .04 apart so it should breathe fine. 
George


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## gbritnell

Here's the second update for today. I designed the parts for the ignition setup. They consist of the timer lever which will hold the Hall sensor. It will be clamped into the slot with a piece of .015 against one side. I didn't want to just use the 0-80 screw against it figuring it might put too much pressure on one spot. The timer lever has a bronze bush as the shaft will turn inside of it. It will be secured with a 0-80 socket head screw and allow about 15* timing adjustment. The other disc holds the magnet. I made it like you see figuring that the minute amount of weight on the magnet side would be offset by the stock on the other side of center, who knows. 
I'll be off for the weekend as the wife and I are going to the model engineering show in Zanesville, Ohio. 
More updates next week. 
Oh by the way, the carb drawing has a note that says solder a short piece of .062 tubing into the mixer. I don't understand this. Maybe one of the Tiny veterans can explain it.
Thanks,
George


----------



## putputman

George, I soldered a piece of 1/16 O.D. tubing into the spraybar so I could use 1/16 I. D. plastic tubing from the fuel tank to the fuel mixer.

I like your timing mechanism. It looks like it will really compliment the rest of the engine. I have tried to dream up something similar to that but I just couldn't come up with anything. 

I have one concern. Every time I have talked to Roy Sholl he told me not the mount the hall sensor on metal. I have always either use a plastic mounting or have use shrink tubing as an insulator between the hall sensor and the metal mount. Maybe I misunderstood what he was telling me so I am interested in seeing how your unit works out.

Looks like it is getting close to making noise.


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## GailInNM

My Hall devices have all been mounted on metal. On TINY it has aluminum on 3-1/2 sides.
Gail in NM


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## lee9966

putputman  said:
			
		

> I have one concern. Every time I have talked to Roy Sholl he told me not the mount the hall sensor on metal. I have always either use a plastic mounting or have use shrink tubing as an insulator between the hall sensor and the metal mount. Maybe I misunderstood what he was telling me so I am interested in seeing how your unit works out.



I just ruined my second hall sensor, I had it mounted on metal inside heat shrink tubing. My guess the first time was that I had a poor ground on the engine body and the spark decided to ground through the chip. The second time the ground was just fine, so I don't know what happened there. Good thing the sensors are so cheap, I ordered ten of them.

I think I will mount one in a plastic block. I sure wish I knew what made the first two fail. 

Lee


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## gbritnell

I have all of my Hall sensors mounted in aluminum brackets. The only problem I ever had was because I used sensors of unknown origin. I have good ones now and have many, many hours on my engines with no trouble. 
The biggest problem I've had is having a poor ground and allowing the high voltage to leak back through the Hall sensor. They don't like that at all. Here is a picture of the Hall sensor mount on my 4 cylinder OHV engine. The one on my 302 is similar but I don't have a recent picture of it. 
George


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## GailInNM

It's been a week since Jim left. I spent the first two days recovering. When we play with toys, we play HARD with toys. And, with him being about 10 years younger than I am he has a little more energy.

Then back to TINY. Since we had cooked two o-rings, the first order of business was to replace the cylinder with one that I had made up with increased cooling. Cylinder temperature did not really change very much so I did not do a sustained high speed test run. Since I had lapped the cylinder so it had a smooth finish and a parallel bore it was only about an hours work to make a new piston out of cast iron and lap it to fit the cylinder. I lapped it a little tight as is my practice. It took about 10 minutes of running for it to find it's own fit. Cylinder temperature dropped considerably, down into the 125 degree F range when running hard, and when running rich at about 2000 rpm the cylinder temperature was down to where I could press my finger on the fins for about 10 seconds before it got uncomfortable.  When running hard, the head temperature would still sizzle spit, but that is sort of expected as there is a PTFE head gasket that insulates the head and no cooling fins on the head. I only made one sustained high speed run of about 10 minutes to measure the cylinder temperature. Also there is noticeably less friction turning the engine over with the exhaust valve held open.

While I am quite happy with the results of the lapped piston, I do not recommend it for first time builders of IC engines. The o-ring gives very satisfactory results except for high speed sustained runs. It is easy and very forgiving. If someone wants to do a lapped piston, I would suggest that they do a 0-ring version first and get all the bugs worked out. I have lapped many piston/cylinders so it was easy for me, but lapping is an acquired skill and should be left until you have the engine running with an o-ring first.

One problem with the lapped iron piston. I have more vibration due to the heavier piston. The aluminum piston with o-ring built to Arv's drawing weighs in at 1.39 grams. My first Iron piston weighed 3.66 grams and Tiny would "Walk" around the bench a little bit at any thing over about a guestimated 3000 rpm. Piston was reworked by thinning the crown and skirt down and got to 2.44 grams. Still more vibration than I would like at high speed. I have made up a grooving tool to thin the piston wall above the wrist pin and think that I can get another 0.3 grams out of it. If not, I can live with the vibration level it is at. 

I have lost track of total time on the engine, but I have put about 90 ml of fuel through it with the iron piston. That is about 8 to 9 hours. The needle sensitivity has improved with the iron piston and I now have a little over one turn between full rich and full lean. It will start reliably on one flip anywhere within the 3/4 turn range in the middle of this. Fuel mix now in use is regular gasoline with 3 percent WD40. I still have lots of lube on the iron piston so will drop to 2 percent WD40 the next time I mix a 100 ml batch of fuel.

Other tidbits for those thinking of making a hit or miss out of tiny. Some time back I removed one of the flywheels. I could not tell any difference in operation except that it accelerated up to speed a little bit faster. In it's current configuration, running about 1/2 throttle, I can hold the exhaust valve open for about 3 to 4 seconds and the engine will catch on the first stroke after I release the valve. I then takes about a dozen power strokes to get back up to speed. 

I have a hit-n-miss governor drawn up, but I really don't like it much. Want to mull it over for a few more days before I actually build it.

As soon as I take a couple more photos of assembly, I will post my version of the spark plug along with a drawing. Nothing really unusual with it. Just my way.

Lee: Glad you got the wire. If all the people I sent wire out to build a TINY we will have to have a TINY convention. Lots of interest everywhere. I will be watching for your build to start showing up on these pages.

George: Nice looking muffler. I made one that plugs in to the vertical exhaust pipe on mine. Works well, but does not look a s nice as yours. Since TINY is so small it does not make much noise so I run it without the muffler most of the time. Besides the exhaust flap is disabled when running with the muffler and I like to see it bob.

Gail in NM


----------



## gmac

Gail;
Thanks for the "field test data"!! Do you think that changing the cylinder head gasket to copper or some other conductive material would help reduce head temp and put the cylinder barrel finning to work sufficiently to be worthwhile doing?
PS - I assume it was Viton o-rings that were failing.
Cheers
Garry


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## GailInNM

Garry,
A copper or soft aluminum would probably move some of the head heat into the cylinder. Before I was trying to keep the heat out of the cylinder because of the 0-ring. Yes, they were Viton o-rings, but remember that I was abusing them to see what would happen. In any normal operation they would not fail. I got 30 hours on the first one keeping high speed operation down to maybe 5 minutes at a time. I was interested in seeing what they would take in the way of abuse if I decided to try them in a higher performance engine. Using TINY as a test bed. Unless some one just wants to play, the o-ring is the way to go.

Are you building any engines these days?

Gail in NM


----------



## littlefold

Gail,
I wanted to let you know I got the package.
Thanks for the wire and the spark plug parts and the other stuff.
I got all my metal from Speedy metals and will start tomorrow afternoon.
I tell you with the price that Speedy metal sells there stock,I will buy from them from now on.
My wife had the mail in her car from yesterday and I just found the package.So quick shipping on that also.
Thanks for everything.
Tim


----------



## gmac

Gail;
I'll be watching for your test results re: higher performance engines and O-rings - I don't look forward to my first attempt at cast iron rings!

I've been slowly making small parts for an Upshur Twin (with BMW Motorcycle cosmetics), Ron Colonna's Offy and the Bentley BR2 - however I'm limited on the last two due to equipment (Taig lathe and X2 mill). Progress has been slow, I had a little go around with my heart and the emergency ward; plus moving into digs that are not machine shop friendly!

I'm living my dreams thru this website..... :big:

Keep up the great work - I'm silently watching and learning.
Garry


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## gbritnell

Well here's the latest update. I have the carb finished. I looked for some 1/16th ID tubing but couldn't find any so I went in a different direction. I made a hard line from brass. The carb end has a tapered cone fitting and the end that goes into the crankcase/fuel tank has a compression washer made from Teflon. 
I finished one spark plug. I changed the size to 8-32 to make it a little more manageable. All that's left to do now is mount the Hall sensor, drill and tap for the timer arm and clean and polish the parts. I should be able to see if it will 'pop' within the next few days. 
George


----------



## GailInNM

Looks great, George.
I am shifting from looking mode to listening mode already.
Gail in NM


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## putputman

I'm with Gail, just waiting for that popping sound. Engine looks great.

I am also curious as how that spark plug will work set so far back from the cylinder. That will sure make it simpler in a lot of I.C. builds.

BTW, I have about 10 ft of the 1/16 I.D. tubing. If any of you Tiny I.C. builders need some, PM me with your mailing address and I'll send you a piece.


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## awJCKDup

I just finished my "Tiny" this week, had it running and it runs good, but I still want to do some tweaking to it, but somehow I've managed to kill the hall effect sensor. I've got some on order, so until then all I can show you is some stills. Thanks Putputman for the plans, I hope my own changes are acceptable.
John


----------



## putputman

John, that is just beautiful. All that brass really stands out. The base is very unique also.

On the middle photo, it looks like you might have a throttle control. 

Looking forward to the video


----------



## cfellows

Great job, John. Wouldn't mind getting a little more information on the carb (throttle control?).

Chuck


----------



## awJCKDup

Thanks guys, Yes it is throttle control, thanks to a previous post by Kcmillin. I just followed what he did, basicly just lengthened the carb and added a barrel type valve. She idles down nicely, but between say 15% open and wide open there doesn't seem to be a very big difference. I'm not very inovative but I sure like to copy what I think is the best of everyone's build. I wish Gbrit would have started sooner, I love the way he beveled off the rear frame and made the timing adjustable.


----------



## littlefold

John,
The engine looks great!
I like the way you slotted the head.Can't wait to hear it!
The base is fantastic with the bent piston.
Tim


----------



## JRNYMAN2LMAYKER

I love your version of the Tiny!!!! I am particularily fond of the cylinder and head as I have been toying with the idea of an air-cooled version. 
I was wondering if you made the cylinder out of aluminum with a cast iron sleeve or solid cast iron?


----------



## awJCKDup

Thanks everyone, Greg by trade I was an electrician, so I don't have a good knowledge of materials and which is best for which application. I made the cylinder out of stainless steel, so I could get a high polish and not have to worry about it again, maybe not the best choice-I don't know --but it is what it is.


----------



## gbritnell

Well here's a video of the first running. It's not very long but I am still tinkering with adjustments. I don't know where to set the timing. I have had it all over the map. I started about 5* before TDC and it wouldn't keep running. I kept advancing it and found a spot at about 20* BTDC where it seemed to run best. The carb was built to the drawing specs and I can only get about 1/4 of a turn from not running to running too rich. The compression feels good but I think I might make a new piston to increase the compression ratio a small amount and see it that helps. 
George
[ame]http://www.youtube.com/watch?v=9R-ZcnXvVpE[/ame]


----------



## kustomkb

Nice job George!


----------



## GailInNM

Congratulations on another runner, George. Thm: Thm:

I had to change my fuel mixer to get increased adjustment range. When I started I was at the "I think I moved it" stage for going from to rich to too lean. I opened up the longitudinal hole from 0.018 to 0.020 with a #76 drill bit and used a #10 Sharps sewing needle which measured 0.0195 for the needle. Measure the needle if you do this as I found some variation in diameter. This let the needle form a narrow passage to let the fuel flow through. I now have about 1-1/2 turns of operational range.

My timing is not adjustable on the fly, but did not seem to be very critical in between run adjustments. It is currently at about 10 degrees BTDC, but I can't tell the difference 5 to 10 degrees either way. I would like to make up an adjustable timing like you did sometime just to see what happens real time.

My compression is 5.6 to 1 currently.

Gail in NM


----------



## Metal Butcher

Congratulations George! :bow:

Its great to hear it running, and it sounds really nice.

It runs real good to, even with out a head gasket.  stickpoke

You never cease to amaze me! Thm:

-MB


----------



## awJCKDup

As always George that is a sweet little engine. My needle valve adjustment also seems to go from lean to rich in a quarter turn or less. I've been running my timing around TDC, will have to bumpit up a bit and see how she runs. After I get my new hall effect and change it out. Your's seems to rev a little faster than mine, any idea of the RPM ?
John


----------



## kcmillin

Great Job George! It runs as good as it Looks! I love the sound, in fact when I seen your first post of the muffler I secretly made one similar, to see what it was going to sound like. 

My experience with the time is like everyone else, all over the place. I even had it running by timing it for ATDC up to about 15 degrees or so. I currently have it about 15 BTDC. The mount I have allows about 10 degrees of adjustment while the engine is running. 


John, I have recorded RPM's from anywhere between 1200 and 7200 RPM. When I take the tach off the crankshaft it spins even faster, my estimate about 8000 RPM.

Kel


----------



## GailInNM

A couple of members wanted more information on my spark plug. Attached is the drawing of my current spark plug in PDF format. This is my working drawing and not polished. Ignore the 4 place decimal. Thats just how I do my working drawings and should not be taken as high precision being necessary.

The photos are of the parts as machined and forming the electrode. I did not take any photos of the machining operations. The only thing unusual is the milling away of the extra housing length to for the ground electrode. I gripped the body on the hex in the milling vice and then used a 4 flute 1/8 end mill to remove the extra material. I took 5 passes on each side starting at the top and removing about 0.035 material on each pass. Cut one side and then the other before down feeding the cutter 0.035 for the next pair of cuts.

The electrode was formed over a scrap of 1/16 sheet metal with the edge broken to give a slight radius. I bent the electrode over with a scrap block by hand and then tapped it down with a small 4 ounce hammer. I could not hold the sheet metal form in place well enough so it slid away some, but the electrode was squared up later after assembly and the final gap set then

The assembly operations will be in the next post (or two).

Gail in NM






















View attachment SPARK.pdf


----------



## GailInNM

Assembly starts with soldering the 0-80 screw to the end of the electrode. I used some 0.015 electronics solder to form a ring. Solder ring slid on the electrode and the end of the electrode is dipped in flux. Screw slid on and the ring slid up to the screw. ZHeat gently with a small torch until the solder flows. Doesn't take long with parts this small.









After cleaning up the excess flux and any extra solder, the electrode is ground to final length. Insert the electrode in the insulator. Measure the length from the top of the screw to the insulator. The electrode wants to be about 0.015 longer than this. The photo shows before grinding with the wire protruding about 0.093. Remove the electrode from the insulator and grind off the end until the end will protrude about 0.015 inch. If you go too far then shorten the electrode big end a little bit.


----------



## GailInNM

The rest of the assembly is just gluing the parts together with epoxy. Use a fairly thin epoxy so the excess can squish out between the insulator and body when assembling. I use ordinary 5 minute epoxy.

First the wire is glued into the insulator. Coat the wire with some epoxy and press into the insulator. Clean off any excess epoxy.










After the epoxy has cured on the wire, coat about half of the insulator at the small end with a fres h batch of epoxy. Insert the insulator into the body until the tip of the center electrode almost touches the ground electrode. 
Clean off any excess epoxy. Use a feeler gauge or a small piece of 0.025 sheet metal between the electrode tip and the ground electrode to set the gap at about 0.025 inch. If you are gentle you can remove the feeler gauge. Allow the epoxy to cure.

















Tweak the ground electrode to set the gap if it has changed and you have a finished spark plug.


----------



## Metal Butcher

Good post Gail. I totally understand after seeing the pictures and your print. When the time comes for my turn at one of these small ones, I'm sure I can do it.

Is your plug lined with Delrin, or one of the other materials you listed on the print? I'm looking at the earlier print in the archive. I just spotted the latest one in your post, and it specifies Corian.

-MB


----------



## GailInNM

MB,
Yes, the current plug insulator is Corian (acrylic). My first plug used Teflon (PTFE). PTFE has a better voltage breakdown and higher temperature rating than either Corian or Delrin (acetal), but is so soft that it makes it hard to machine. A lot of people have used (including me) have used Corian with out a problem. Delrin should work very well if you happen to have some. Probably ought to cut some shallow grooves in the side or otherwise prepare a rough finish for the epoxy to grip on as almost nothing will stick to it. Same problem with PTFE. All are satisfactory so take your pick.
Gail in NM


----------



## Metal Butcher

Thanks Gail.

 I'm soaking up all the info I can find, like a fresh sponge.

-MB


----------



## awJCKDup

Got my new Hall effect sensor in the mail today , got it installed, played around with the timing a bit, and carb. So I shot a video. New to all this photobucket--youtube stuff so I hope it works.
John

[ame]www.youtube.com/watch?v=BJM7C6sCb2g[/ame]


----------



## kcmillin

She runs good John. Thm:
Nice job, all around. The throttle seems to work out for ya pretty good. 

The fuel tubing between the carb and head should help out with the vapor lock problem some of us have had.

Kel


----------



## Metal Butcher

Hi John. The video is super! Your engine sounds really good. Congratulations! :bow:

I would love to see (close up pics?) and hear the details about the throttled carb, is it an off the shelf item?

How is you Hall sensor mounted?

And also the connector plugs you used on the base to hook up your CDI.

An inquiring mind would like to know. ???

-MB


----------



## awJCKDup

Thanks guys,
  Kel-The fuel tubing does keep it from vapor locking, but I'm gonna change something, it's just suspended there on tubing, also if I stop , it manages to siphon fuel out of the tank, onto the base. I would like turn the carb out some, attempted it once-- made another part that went into the "oops" box.

MB--The carb is from the prints with the addition of a valve that Kel showed in his post on page 9 of this post. (Thanks Kel) I mounted the hall sensor on a thin piece of Plexiglas that is mounted just above the fuel tank, the wires enter the frame and snake over to a point where I drilled a hole down through the wall of the fuel tank to get to the base.
The connectors came from A MAIN HOBBIES.com I used E-FLITE EC3 device and battery connector (pn EFLAEC303). The Hall sensor is connected using Futaba style connectors (pn PTK-5008) which were compatible with the connector on the sensor from S and S machine.

Hope that helps
John


----------



## gbritnell

Well I played around with 'Tiny' for several hours today, double checked the seal on the valves, installed a new 'O' ring on the piston and sealed the head gasket surface. It fired right up but I'm still not convinced about the 'O' ring. I can't start it by hand like
John does with his. I'm happy with the outcome although I think I will make another piston with a cast iron piston ring and try that. Here's the latest video clip. I used a model airplane engine starter and put several layers of Duct tape around the aluminum starter hub. 
George
[ame]http://www.youtube.com/watch?v=xJ7JRRNpJ6c[/ame]


----------



## awJCKDup

George, she sure sounds like a good runner. My video was a best case scenario, I already had it running so it was warmed up. When cold she is a bit more stubborn. After you guys talked about timing, I bumped mine up abit, seems to run better, but occasionally at mid throttle it will start to surge. i'm not sure if this would be a carb thing or a timing thing. Any ideas?


----------



## gbritnell

I started with my timing about 5* BTDC with the timing lever available to add 15*. When I got it started and got the carb adjusted as well as could be I moved the timing lever to more advance. I could hear it smooth out just a small amount. When I would move it back it sounded like it was laboring a little. When I flip my engine over I can hear the intake valve vibrating as it's being pulled open but there's not much compression. As the engine heats up and parts expand there's enough compression to stop the piston from going over center when you flip it by hand. I would like to feel more compression when cold so I'll play with it. At that point maybe the timing will make more of a difference. I'll let you know what I find out. 
George


----------



## Metal Butcher

John. Thanks for all the information. I already found the plugs, and their the way I want to set up my ignition. I also found the throttled carb details provided by Kel. The set up looks real good. I couldn't picture it in my mind and would have never thought of of doing it that way, outside of the convention buttery control.

I know very little about I.C. engines, but based on my experience with faulty I.C. powered yard equipment I would blame the surging on contaminated fuel. Is it possible theirs microscopic particles left over from the machining? Or fine particles in the fuel? I'm just guessing that might be the cause. I think I'llclean my fuel system parts with an ultrasonic cleaning unit, and run my fuel mix through fine filter paper just to eliminate that possibility.

Question; Is there any special wire you would recommend between the CDI and the engine mounted ground/spark plug wire? should they be separated?

-MB


----------



## awJCKDup

MB I had Tiny hooked up and running on the bench with just cheap jumper leads and had no problems. But for the final hookups I used Test lead wire, for the plug wire and ground, mainly because of it's flexibility. I ran the ground and plug wire together in some tubing. The sensor wires I ran in a different tubing. I would try to keep the ground and plug wire separate from the sensor wires, although when I was bench running Tiny I had wires crossing and running over top of each other with no ill effects, except when it got flooded, then I had a problem with some arcing.

John


----------



## kcmillin

George, Have you tried a new O-ring? I had an issue with compression and upon replacing the O-ring (which was brand new already) I had better results with some verses others that cam put of the same bag.

I also added .020" to the top of the piston, to bump up the compression a little bit, however I did have to notch the piston a little to clear the spark plug. 

Currently the compression is pretty darn tight, when I turn the engine over slowly I can feel it fire ever so slightly. If the intake spring holds tight that is. I got her pretty light.

Kel


----------



## Metal Butcher

awJCKDup  said:
			
		

> MB I had Tiny hooked up and running on the bench with just cheap jumper leads and had no problems. But for the final hookups I used Test lead wire, for the plug wire and ground, mainly because of it's flexibility. I ran the ground and plug wire together in some tubing. The sensor wires I ran in a different tubing. I would try to keep the ground and plug wire separate from the sensor wires, although when I was bench running Tiny I had wires crossing and running over top of each other with no ill effects, except when it got flooded, then I had a problem with some arcing.
> 
> John



John, Did the arcing occur between ground and plug wire, or the plug wire and sensor wire?

Did you need to replace the hall sensor after the arcing?

George, If you would like to try some O-Rings from a different batch let me know the size or industry number. I have a good supply of various sizes on hand. Good ones, not from a low cost discount assortment.

-MB


----------



## GailInNM

John., Nice running engine. Runs as well as it looks.

George, you mentioned trying cast iron rings. The smallest I have ever made were 1/2 inch diameter. That was a while ago and while my skills have improved some the 3/8 diameter still spooked me. That's why I took the cowards way out and did a lapped piston. I figure that rings should be about 0.013 inch square section. I will be watching to see how you make out if you try it.

I had problems with dirty fuel with the close fitting needle valve in the mixer. I started filtering mine through a coffee filter at that cured the drifting needle valve setting. I bought some standard lab filters, but have not used them yet. 

I am using small test lead wire for my HT and ground connections. 

Gail in NM


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## awJCKDup

MB
The arcing was actually across the lugs on the coil on the cdi board, that's like an inch apart. I believe the sensor failure was from some dummy unintentionally touching the cdi board while it was running.......smarts a bit too. and yes that is when the sensor expired... lesson learned, I have spares now.


Gail-Do you run gasoline like George does, or do you use Coleman fuel?

To anyone who wishes to comment.....My CDI is separate from my engine, so that I may use it on other engines I build. It currently resides in a plastic container because I can't decide fitting home for it, a couple ideas I had were 1) put it in a wood box made to look like an old Ford Buzz coil 2) Put CDI inside a small block chevy distributor cap, old small diameter style with the little window in it. Have the plug wire and sensor wires com out of different plug towers.


----------



## Metal Butcher

Test lead wire is 18-AWG (.040").

I have some soft black 14-AWG (.064"). Insulation is .140" O.D.

It should work? Its nice and limp too, like "Honey's" well done pasta! stickpoke

-MB


----------



## Metal Butcher

awJCKDup  said:
			
		

> MB
> The arcing was actually across the lugs on the coil on the cdi board, that's like an inch apart. I believe the sensor failure was from some dummy unintentionally touching the cdi board while it was running.......smarts a bit too. and yes that is when the sensor expired... lesson learned, I have spares now.
> 
> 
> Gail-Do you run gasoline like George does, or do you use Coleman fuel?
> 
> To anyone who wishes to comment.....My CDI is separate from my engine, so that I may use it on other engines I build. It currently resides in a plastic container because I can't decide fitting home for it, a couple ideas I had were 1) put it in a wood box made to look like an old Ford Buzz coil 2) Put CDI inside a small block chevy distributor cap, old small diameter style with the little window in it. Have the plug wire and sensor wires com out of different plug towers.



All of the above are nice ideas. Based on the high quality workmanship of your engine base, I would recommend using your talent to make a small walnut/oak/ect wood, finger jointed box, with nice brass trim and hardware. A hinged lid would allow you to store the wires inside went not in use. 6" x 4" x 2" or so if your using 4-AA rechargeable batteries. Two small notches on the side just below the lid (for the ignition wires) would allow it to be latched while in use. Keeping the lid down and latched would help to keep wandering fingers at bay! 

If you don't already have a battery holder (4-AA), Radio Shack has a real nice one for $1.99.

http://www.radioshack.com/product/index.jsp?productId=2062253

-MB


----------



## awJCKDup

Thanks for the input MB


----------



## GailInNM

John,
I started out using Coleman fuel (naphtha) but have since switched to gasoline. With the naphtha I tried running 1 percent two cycle oil in it for lube and it burned quite dirty. Switched to 5 percent WD40 with the naphtha and that was much better. Then tried regular gasoline with 5 percent WD40 and that made starting much easier and control was much easier. Then I switched to a lapped cast iron piston. This was a big improvement, still with 5percent WD40. Since there was still obviously plenty of lube I have dropped to 3 percent WD40. Exhaust is much cleaner and the piston still has plenty of lube and runs smooth. I have over 10 hours running on it with the 3 percent mix. I will be out of mixed fuel tomorrow and am going to drop to 2 percent for the next 100ml batch. I think it will be fine. It will filtered.

MB,
Test lead wire comes in all sizes. I bought a bunch when I needed some very flexible wire for some RC motors I was making. I have 21 gauge (0.080 OD) and 28 gauge (0.050) gauge. I am using the 28 gauge as I think it looks more to scale. The 28 gauge insulation is only good for 6kV so when I ran it through my metal base I ran it through some small silicon fuel line. 6kV is really OK as there is only about 4kV when the spark plug fires unless it is flooded. Then it gets above 20kV. BTWl if a Tiny builder needs some of either I can cut some off an mail it. Just can't be too choosy about color.

John, you obviously have a more artistic eye than I do, so what ever you do I am sure will look good. My work tends to be more utilitarian based on straight lines with even dimensions.

I think this group has 5 Tinys running now with at least 4 more under construction that I know of.

Gail in NM


----------



## awJCKDup

Thanks for the info Gail, I think I will give the gasoline and the filtering a shot.

Arv--Your first post for Tiny was in Jan.---Did you ever think it would produce the results that it has---Great little engine---Thanks again for posting the plans

John


----------



## kustomkb

Man, you guys really dialed this thing in. I never really grasped the "Tiny" scale until I saw John's fingers.

Thanks Gail for the spark plug tips, Kel for all your carb and other input, John, welcome and awesome job, George, thanks for all your design inputs.

And of course put put man for this great design and new plague to hit the members.

 ;D


----------



## Metal Butcher

GailInNM  said:
			
		

> MB,
> Test lead wire comes in all sizes. I bought a bunch when I needed some very flexible wire for some RC motors I was making. I have 21 gauge (0.080 OD) and 28 gauge (0.050) gauge. I am using the 28 gauge as I think it looks more to scale. The 28 gauge insulation is only good for 6kV so when I ran it through my metal base I ran it through some small silicon fuel line. 6kV is really OK as there is only about 4kV when the spark plug fires unless it is flooded. Then it gets above 20kV.
> Gail in NM



Gail, You are correct. I should have said 'all my' test leads are 18-AWG. That's all I have on my equipment, and some salvaged spares that are too short for my purpose. A quick check on the internet shows that wire of many sizes including some not normally used on test equipment Ive seen and also covered with stiff PVC referred to as 'test lead wire'. 

The spool of black silicone 14-AWG that I found in my collection will be used to connect the remote CDI box to the plug mounted on the base's of my up coming build's, unless some one who understands proper wiring says I shouldn't use it. From that point to the spark plug and a grounding lug on the engine, I'll be using the 3/32" 10 KV wire supplied by S&S. Not sure if the scale you mention will be correct for "Tiny" but that's what I'll be using on my larger first builds. I wonder if the spark plug wire that S&S supplies is also considered a 'test lead wire'?, or is it something else? What actually defines the description 'test lead wire'? ???

Wow, there's a lot for me to learn before starting a first I.C. build. 

-MB


----------



## Metal Butcher

During the course of some preliminary planning I considered the shape's and construction method's commonly used on small fuel tanks for I.C. engines, I realized that tanks soft soldered together could be a cause of fuel contamination, and lead to erratic operation.

When applying heat to fluxed tank joints, Rosin flux will thin out and spread on the interior of the tank. 

The use of a solvent or cleaner that will completely dissolve and wash out the baked on flux inside of fabricated fuel tanks and carburetors is needed.

-MB


----------



## lee9966

Wow, I go away for a few days and look at all the videos!

First attempt starting mine today, ran for 20 secs or so each time. Not a surprise since I haven't done any tuning except to find the very tiny spot where the carb adjustment lets it run.

I need to get the photos out of my camera, although to be honest everyone elses look much nicer than mine. Maybe I should blur the pictures?  :big:



Lee


----------



## gbritnell

Hi Lee, 
Just the fact that you built one and it runs is what this forum is all about. Anyone who creates something with their hands has accomplished a great deal. Whenever you get a chance post a picture or video. 
As far as the sweet spot for running, I have the same situation with mine. I spin it over until I hear it start to pop a little and from that point the carb can only be minutely adjusted before going too rich or lean.
gbritnell


----------



## GailInNM

Congratulations Lee,
Twenty seconds!! That counts. We now have 6 running Tinys. 
 Thm: Thm:

Actually, I was thrilled the first time mine ran for 20 seconds. Just a matter of refining one thing at a time and it will be a steady runner. Now it is one flip starting and then let it run for 10 or 20 minutes at a time for background "music" while I am doing something else.

My Tiny is torn down some what for some more modifications. More on that later today (I hope).
Gail in NM


----------



## NickG

I just love this tiny engine, this thread is awesome. Hats off again to Putputman for doing such a good job designing something from scratch, putting the design out there for people to try and not only that but everybody is getting a runner.

 :bow:


----------



## putputman

Wow! I have been away from the forum for a couple days and they are three new engines running.

John, that throttle control works real well. I am going to add that to my engine. And yes, I am really surprised and tickled with all the activity Tiny has created. It is especially nice to see some people build Tiny as their first I.C. engine.

I can't believe all the fine tuning that Gail has done with this little engine. Between him and George there is a lot of good information that can be used on just about any small I.C. engine. 

I do not have any background in I.C. engines so when I get one to run at all, I do not fool around very much trying to fine tune them. I have found that just about all of my engines are timed at TDC to slightly retarded. The only engine that run better at advanced timing was the V-Twin which was set at about 8* BTDC. On the three Associated engine I just complete I am using CDI ignition fromm S/S and have built an adjustable timing device similar to Georges. All three of those engines also run best at TDC or very slightly retarded. ??? ??? ???

Lee, I'm looking forward to some pictures and videos. Don't you dare blurr them.


----------



## awJCKDup

Lee if it runs for twenty seconds, it's a runner. Please post pictures!

Gail---Seriously? One flip starting?---Very Impressive, how about some "tuner specs. and tips" Mine can still be tempermental at times, especially when cold.

Just a thought, but if anyone is good at photoshop, a combined group picture of the "Tiny Family" would be neat.

John


----------



## lee9966

I may have found what made two hall sensors defective. I too am using the S & S ignition. I had the plug wire off, holding it still, when I saw the ignition was on. When I turned it off I got a nice shock from the plug wire.

Now I wonder if perhaps I had taken the plug wire off and then turned off the ignition in the past. Maybe that's what defectivated the sensors.  ???

Just my thought for the day.

Yes, pictures coming. Really. 

Lee


----------



## GailInNM

John,
No special tuner tips. Just tenacious as a bulldog. Actually I am having so much fun that I don't mind taking it apart at trying something new. It's so simple that all the important parts can be taken off and put back on in under 15 minutes. When something seemed to work then I would leave it. And yes, it really does start on the first flip almost every time. 

In a sort of chronological order of the things that were done from the beginning, keeping in mind that it ran from the beginning. Everything is described somewhere in this thread.

1. Changed needle valve to close fitting annular needle. This greatly improved the ease of adjustment from "did I move it" to currently about 1-1/4 or 1-1/2 turns full rich to full lean.

2. Changed fuel from naphtha to gasoline and lube from 2 cycle ashless oil to WD40. Change was done in a number of different steps with final runs at 5 percent WD40 using o-rings and now at 3 percent using lapped piston. Goning down to 2 percent soon as next round of mods tale place. Some where along the way I started filtering the fuel and this got rid of surges while running.

3. Reduced venturi from 0.093 to 0.082. Improved fuel draw and eliminated mixture change from full tank to empty tank.  

4. Replaced o-ring piston with a lapped cast iron piston. This got rid of overheating when running wide open lean for an extended period of time. Top end rpm also seemed to increase some and starting was easier as the reduced friction let me spin it over faster. 

6. I played with compression ratios and they did not seem to make much difference. Currently at 5.5 to 1. 

7. Went to a conventional spark plug negative electrode. I had been using a surface discharge plug. This reduced the plug fouling when rich and made flooding the engine a thing of the past.

For starting, I have a 3/4 inch knurled knob. I had made an extended crankshaft so it just fits behind the rear flywheel. My flywheels are quite smooth and difficult to get enough friction to start with finger on the flywheel rim. I can do it, but I have to put a lot of pressure on the flywheel. Smoothness comes from one of my extended full throttle runs. I put a load on the engine with a rag with metal polish. About 10 minutes on each flywheel. 

Because of the annular type needle valve, fuel does not flow back to the tank draining the fuel line when stopped. Surface tension of gasoline and all that sort of thing. The key to first flip starts is to stop the engine with the ignition while there is still fuel in the line. I takes a little effort to get fuel past the needle valve if the fuel line is dry, usually choking for several revolutions after the fuel is up to the mixer. Then, even if the engine has set for a day it will start right up. If the engine is cold and I shut it down while running lean, I open the needle valve up about half way between rich and lean positions.

Gail in NM


----------



## awJCKDup

Thanks Gail, a lot of good info, in one easy to find location. I thought my Tiny was finished, but I think it needs more tuning. Gonna go back and read about the carb needle change. Thanks again
John


----------



## kcmillin

Gail, I like your method of polishing the flywheels. Make the engine work for you, now thats cool. 

This annular needle you speak of. Is it still a sewing needle, just more taper? I have not yet used a sewing needle. I have been using piano wire. By putting it in the lathe and using a dremel with a grinding wheel, I put a taper on the end of it, then using light pressure and high grit sandpaper I smooth it out a bit. I have made about 5 of them so far and it seems the one's with the longest taper work best. 

I have yet to try filtering the fuel. I probably should though, I still haven't made a fuel cap yet. :hDe: and there is without a doubt dirt running through the engine, especially with my crude method of mixing and filling the fuel.

Kel


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## GailInNM

The annular needle setup was done with a sewing needle. They are smooth and have a uniform taper up to a point where they become parallel. The idea is to make the longitudinal hole in the spray bar just large enough that the needle can enter with the parallel section to form an annular passage for the fuel. 

I opened up the longitudinal hole from 0.018 to 0.020 with a #76 drill bit and used a #10 Sharps sewing needle which measured 0.0195 for the needle. Measure the needle if you do this as I found some variation in diameter. This let the needle form a narrow passage to let the fuel flow through. 

I posted a chart of the nominal sewing needle sizes in the downloads section.
http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item309

Because of this skinny passage it is very easy to clog with any fine lint or other crud. That's why I keep harping about the filtering of fuel. 

To put the amount of fuel in focus, my Tiny is getting about 30 to 40 minutes on 9ml of fuel for a fuel consumption of 1ml in 6 minutes. Now, a semi-standard definition of a drop is 1/20 of a ml, so a drop will run Tiny for about 18 seconds. At 3000 rpm, that's 900 revolutions, and being a 4 stroke engine 450 power strokes. So each power stroke is using 1/450 of a drop. Not much to be metering.

Gail in NM


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## doubletop

OK I'm hooked; with the number of builds and tips in this thread this has got to be somewhere up there on my next build list. 

No doubt this has been asked before but am I right in assuming that the Kerzel Brian is building over here http://www.homemodelenginemachinist.com/index.php?topic=10831.new;topicseen#new is the basis for the Tiny IC?







Pete


----------



## putputman

Pete, when I designed Tiny I.C., I designed it off the Upshur engine and cut the dimension in half. There are also quite a few changes that I made myself. Some of them are the solid construction of the frame instead of fabricating it. The built in gas tank like I used on a larger engine I built several years ago. The connecting rod is different then anything I have ever seen and came about because of space limitations.


----------



## doubletop

Sorry hadn't wanted to appear to be accusing you of plagarism just the coincidence that these designs are similar and was curious. I'm looking for a next build and this may just be it I do like the variations everybody has included.

There are soem marked similarities between the two types (if not size) and on the tank I see Brian was questioning whether or not to put his underneath.

Its a great job by everybody with the various improvments each have contributed.

Pete


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## GailInNM

My Tiny is put back together but the main modifications have not been installed. Just holes drilled and tapped in the frame to bolt them on later. One modification that I did complete was to put a three pin connector in the rear of the base. There is already one there for charging the battery so this one is of opposite gender so the charger can not plug in. The connector is just wired in parallel to the hall effect pickup so I can plug in some ancillary devices. A tachometer to display rpm with out having to fiddle around with holding up a photo tach or mechanical tach. Leaves both hands free for tinkering. A voltmeter to check battery voltage while the engine is running, and a timing light LED to verify the hall effect device is operating and to aid in timing. Nothing very exciting. 

I plugged a surplus tachometer in that was supposed to be happy with that type of signal. It wasn't. Not too supprised as it ws old when I got it used for a couple of dollars. So, since Tiny is portable I carried it back to the electronics bench and hooked it up to my scope which has a calibrated interval counter in it. 

Wide open it was dead on 10ms per revolution and very steady. Full rich was 45ms with some jitter as it was occasionally misfiring. This translates into 6000 rpm and 1330 rpm to answer the "how fast will it go" and "how slow will it go" crowd.

Gail in NM


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## GailInNM

"Tiny" has gone missing. Actually Hit-N-Missing. Just a couple of teaser videos to show the work from this last week.
Video are with junk box springs in the governor and Tiny is running about 3700 rpm. New springs are about to be wound and there are a few other adjustments to be made. This coming week I will try to get some still photos up and maybe some more video as the tuning progresses. Busy week upcoming so I may be a bit slow.
Gail in NM 

[ame]http://www.youtube.com/watch?v=0samHGH4dPw[/ame]
[ame]http://www.youtube.com/watch?v=ONUecyBnxoY[/ame]


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## lee9966

That's great Gail! I can't quite see how the cam follower is being held away from the cam for the "miss' cycles, but I bet more info will be coming

Lee


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## GailInNM

Lee,
Here is another video showing the detent on the cam follower on the left. Operation is as follows.
The bell crank on the right side has a pin that is engaged in a spool that is driven by the pivoted weights in the flywheel. It moves the bar that is just above the cylinder so when it is extended to the left by the bellcrank it engages the detent on cam follower the next time the cam follower is operated. This holds the exhaust valve open. As the engine slows down the bar is moved back to the right and the follower is allowed to return to rest on the cam for a normal power stroke.  Both the cam follower and the detent bar are hardened so there is a sharp edge for a uniform trigger action.

I have a new camera and am still learning how to use it to get close up video, preferably without getting oil on the pretty new lens. ;D Bear with me. 

Gail in NM

[ame]http://www.youtube.com/watch?v=x12_EoLI7-U[/ame]


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## Metal Butcher

Wow! That's really nice Gail! I love the sound and all the action. :bow: :bow: :bow: :bow:

The experts on this forum are motivating me. I can't wait to see my first I.C. running. 

-MB


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## NickG

Argh!! I can't see the teaser videos here - that's teasing even more! 

I can't wait to get home, wife will go crackers as I will be straight on the computer! ;D

Nice work Gail!

Nick


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## putputman

Gail, I love it. :big: :big: :big:
I was wondering how you were going to squeeze all that activity into the area by the gears. ??? I never thought about putting it on the other end of the crank. Very clever. ;D 
Are you targeting any particular RPM to kick in & out?


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## littlefold

Super!
Great job Gail.
Tim


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## GailInNM

Thanks MB, Nick, Arv and Tim. I am glad you are enjoying the Tiny H&M project. 

MB - We are not experts. We have just made more mistakes than the beginners and occasionally learn something from them. All of us will be watching for your first IC engine.

Nick - Just a little more incentive. Besides this post has a new video with it.

Arv - Now I have played with the rpm range some. The rpm I stated in my first videos was wrong. Did not look at the range setting correctly so the rpm was actually about 3400. I now have played with springs a bit and have settled on 2000 rpm which is what it is running at in this video. I did not design any hysterisis into the design so there is very little variation between pull in and drop out speed. Watching on scope maybe 200 rpm max. I had it running at lower speed, about 1600 rpm, but it would not take a load and recover very well. I have a project in mind for this engine eventually with a variable load so I was targeting that. Since this video was shot yesterday I have improved the hit and miss action so it is much smoother today.

On a slightly different note, before the H&M conversion my fuel consumption has been increasing as I tweaked timing and exhaust cam position. I was down to 40 minutes on 9 ml of fuel. I think this was because the engine was running faster at any fuel setting so while the fuel consumption per stroke was the same, there were more strokes in a given time so more fuel was used. Any thoughts on this anybody or am I full of it?

Continuing on however, with it is H&M mode I have made one sustained run on of 9 ml of fuel and got 2 hours 5 minutes. The run was broken into two parts as my batteries went dead 50 minutes after starting the run. So my fuel costs have dropped a bunch. ;D

Gail in NM

[ame]http://www.youtube.com/watch?v=P4eWX8Vz02Y[/ame]


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## ozzie46

Sweet! It sounds great.

 Ron


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## GailInNM

Thanks, Ron.

During the last run I noticed that a couple of times the engine would slow down going through a few power strokes without firing. It would not stop, just miss a few strokes that it should not. I pulled the plug and had a look. A bit dirty. ;D

Hit it with a blast of brake cleaner and then some compressed air and reinstalled it. I have a micro-grit air eraser (mini sand blaster) but was too lazy to get it out. Engine has run fine since. I don't think I have ever cleaned this plug. It has been in probably 25 to 30 hours, much of it running slow and rich before the hit and miss conversion.
Gail in NM


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## GailInNM

Here are the promised photos of the hit and miss conversion parts for Tiny. 




Top row has the governor weights with spring mounting pins mounted in one of the. Also the spool which is made of SAE 660 bronze.

In the middle are the arms and arm mounts along with a semi-tubular pin used to mount the together.

On the bottom are the cam follower which is made of O-1 steel and hardened. The bushings for mounting it are next to it. On the right is the bell crank attached to the latch which is also hardened O-1 steel and the pivot bushing for the bell crank. 









Detail photo of the governor weights with spring attachment pins Loctited in place with Loctite 680 and a photo of the operating arms with the mounting brackets assembled with the semi-tubular pivot pins.









Operating arms attached to the flywheel and on the other side the weights attached to the operating arms.









The bell crank and latch are mounted on the frame. Notice the pin on the end of the bell crank in the lower right corner of the photo. It is made from a hardened 1mm drill blank and silver soldered to the bell crank. Not shown in a previous photo is the guide for the latch near the left end of the latch. The pin on the bellcrank engages the spool on assembly as shown in the second photo.






The the operating arms are engaged in the spool before the spool and flywheel are slid on to the crankshaft. The bell crank has been left loose so it can be lifted to engage the spool.

Not shown are the springs. They were made of 21 active turns of 0.012 music wire wound on a 0.093 mandrel. When released from the mandrel the expanded to 0.14 diameter. I wound about 30 turns on the mandrel then cut to length and formed the ends after releasing from the mandrel.

Gail in NM


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## rudydubya

Great work Gail, and many thanks for the detail on the governor linkage.  Outstanding as usual. :bow:

And economical too. If my numbers are correct, with that 9ml of fuel over 2 hours and 5 minutes, 2000 rpm, and 1.75 inch flywheels, you're getting 9,126 miles per gallon...  ;D

Regards,
Rudy


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## kcmillin

Great Job Gail!!

You sure know how to fit a lot in a small space :bow: :bow:

I love the pic of the spark plug, Now that is some carbon buildup.

Kel


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## gbritnell

Gail,
What a fantastic project. The many experimentations and the development you have put into this little engine is outstanding. I would recommend to anyone wanting to build a 'Tiny' engine to seriously consider this one as long as you can work in smaller sizes. Although I have built some very complicated and time consuming engines I was completely taken with this one when I first saw it. I even put aside one of my other projects to complete it. I don't have the fortitude to keep playing with it as you have and wish I could get it started by hand but it seems no matter what I do it just won't quite keep going when it is running very slow like at start up. 
Congratulations for your fine contributions throughout this project. I would also be remiss if I didn't include Arv for starting this whole thing.
gbritnell


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## GailInNM

Thank you for your kind comments Rudy, Kel and George.

Rudy, I don't think I will go broke buying fuel. Fuel cost should be around one cent an hour including both the gasoline and WD40.

Kel, The amazing thing is the engine was sill running well with all that gunk on the plug. Actually that was mostly an oil gunk on the plug and not hard carbon.  I pulled the head and it was dirty also along with the combustion chamber portion of the cylinder. It all wiped off with a paper towel. Since it was an oil buildup I have reduced the fuel mixture to one percent WD40. Inspection showed that the cylinder and piston still had plenty of oil. I have run an hour on the new mix and the piston/cylinder still look like they are getting plenty of oil. While I was at it I gaped the plug up to 32 thou from the 25 thou that I had it at. 

Update!! while I was typing this, the engine stopped. The piston was dragging in the cylinder due to lack of lube. It had run about an hour and half on the one percent mix. What I really should do is put an oiler on the cylinder and do away with mixing fuel completely. But for now I think I will just try 2 percent. 

I put a drop of oil on the piston and turned it over by hand a couple of time and it is back to running just like it had been. 

George, I enjoy refining things just as you enjoy putting a fine finish and finish details on an engine. I just want to see them run and as long as the machining marks are gone it is an acceptable finish for me. I like smaller models and have done them for many years. Unfortunately my eyes have deteriorated the last few years where the smaller models are more of a challenge. It takes a 2 power visor to find a 0-80 screw, 3power to tell which end has a head and 5 power to tell what kind of head. But as long as I can keep building toys I am happy.

There are several more "Tinys" underway that I know of. It is a good starter IC engine. It is easy to get running, although like any other engine it takes a little time to get it where you want it. Mine ran stock right away, but was difficult to hand start. Biggest improvement in hand starting was changing to a lapped piston/cylinder using cast iron for both. That's something you might try if you have a lull in your other activities.

****
I think that this concludes my "Tiny" project. I still have to replace the bottom plate with revised engraving for the gasoline fuel, but that can come anytime. Maybe I will build an oiler sometime if I feel the need, but not right away. I have some other projects in mind that I have been drawing while playing with "Tiny". Just have to decide which one to do and order material. 

Thank everyone for their support and following along my portion of this thread. I will still be following this thread and will be glad to help anyone who is building, or decides to build, a "Tiny" in any form. And many Thank You's to Arv, Putputman, for starting this fun project that many of us have been and are enjoying.

Gail in NM


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## NickG

Truly amazing! :bow:


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## Brian Rupnow

Gail---Fantastic work. I admire your conversion to a hit and miss style engine. Now---Help me out guys, please. I am going nuts trying to get some appreciable compression on my Kerzel engine build. Its just not happening. Tonight I screwed an adapter with a small hose on it into the sparkplug hole and tried to blow through the tube with both valves in the normally closed position. I couldn't do it, although if I manually pushed down the end of the valve stem on either the exhaust or intake valves, I was able to blow through the tube with no trouble. This lead me to make a few calculations. Volume of the cylinder with piston at top dead center is 0.093 cubic inches. Volume with piston at bottom dead center is 0.447 cubic inches. This gives a compression ratio of only 4.8:1-----Maybe thats why I'm not feeling any noticable compression when I turn the engine over by hand??? How much compression can you "feel" when turning one of these Tiny engines over by hand?----Brian


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## GailInNM

Thanks Nick and Brian.

Brian: I was just getting ready to respond to your Kerzel thread on compression with some suggestions. I will do so in that thread so people can better follow along. Probably in 20 minutes or so.

A little update since I am here. 
I reset the ignition timing and valve timing and am getting about 2 hours run time on 5 ml of fuel. It is hitting about 1 in every 10 revolutions or 1 in 5 power strokes. I have run on 2 percent fuel now for about 6 hours and pulled the plug. It was a little bit dirty, but not enough to have to clean it. Just an oil film on it. I will put an oiler on it sooner or later however so I don;t have to mix fuel.

Gail in NM


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## GailInNM

A few days after my last post, about 2 weeks ago, I took a break from my next project and put an oil cup on Tiny.
Since then I have run 160 ml of straight gasoline through it. I run it in the background while I am doing other things. I put 5 ml of fuel in it and when it quits running I take a break. I have been getting about 1 hour 50 minutes on 5 ml of fuel. That makes for about 58 hours of running since adding the oil cup. I pulled the plug and there is no oily residue on it. A little bit of carbon, but nothing serious. I brushed it off with a tooth brush and reinstalled it.

I had to offset the oil cup from the center line as there is a cylinder mounting bolt on center line. On the bottom of the cylinder, I cut an 1/8 inch wide groove 1/32 deep and drilled 6 evenly spaced 0.040 holes from the groove into the cylinder. I wound about 20 turns of cotton/polyester thread loosely into the groove to distribute the oil.

The oil cup was turned out of 3/16 brass with the cup part about 5/32 inch long and the cup drilled out with a 1/8 drill. The feed pipe was turned to 3/32 diameter and drilled with a 0.040 drill. It is just Loctited into the cylinder mount. I use 10 weight machine oil, DTE 24, for lubrication. I put 4 drop into the cup for every 5 ml of fuel. I tried 2 drops but s little drag starts showing up after about an hour. 






Just for fun, this evening I pulled one of the governor springs off. With both springs on it was running about 2000 rpm. With just one spring it is about 1100 to 1200 rpm. It would run slower, but I am too lazy to wind more springs. It has been running for 2 hours 40 minutes so far this evening and still going strong. I am going to bed in another 15 minutes if it out of fuel or not. I will update the final run time when I know it. . 

EDIT: It just made it before bedtime. 2 hours 53 minutes on 5 ml of gasoline.

Here is a short video of it at low speed. Now back to the new project. 

Gail in NM

[ame]http://www.youtube.com/watch?v=eKB8uECIksY[/ame]


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## ozzie46

Wow Gail thats neat. 


 Ron


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## GailInNM

It's been a couple of months since I reported anything on Tiny. I have been mostly working on other projects with Tiny running it the background. When things got slow I would make a few mods to Tiny and run it some more.

Some of the major changes have been:
Replace the plain crankshaft bearings with ball bearings.
Replace the cam.
Rework the valves.
Take the play out of the hit and miss governor.
Play experimental games with the piston.

Besides reducing the friction on the crankshaft, the ball bearing mod also included taking some of the side play out of the crankshaft. This was necessary as the side play contributed to the hit-miss governor play causing the engine to hit more than once between miss cycles. 

The dwell angle on the cam was increased by 10 degrees on the cam, 20 degrees on the crankshaft, to make the engine breathe a little more freely and to make the cam position adjustment easier. The cam was changed from steel to SAE 660 bronze at the same time. That was not really necessary as there was no noticeable wear on either the cam or the follower. 

At about 180 hours on the engine the needle valve started to get a little touchy when loading the engine down. It was caused by leakage between the intake valve and valve guide. I knew that I did not get a good finish on the guide when I made it, but had left it alone as I wanted to see the engine run. So the valve guides were re-reamed and new valves made with a little more care this time. Gave a noticeable improvement on the low end rpm recoverable and the needle valve adjustment range was increased.

Removing some of the play in the governor linkage by hand fitting some of the bushings and other areas got rid of the rest of the double hits when it fired.

Lately I have been using Tiny to play with some graphite pistons on an experimental basis. These experiments are documented in a separate thread at:
http://www.homemodelenginemachinist.com/index.php?topic=12591.0
The results have been quite encouraging.

Yesterday I refilled my 500 ml jug of fuel for the third time. So, since starting to use straight gasoline for fuel I have put one liter of fuel through tiny. Most of the time I have been getting 16 to 18 minutes of run time per ml of fuel. Based on that Tiny has 250 to 300 hours of run time on it. Currently with all the changes including the graphite piston I am getting about 21 minutes per ml of fuel.

Gail in NM


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## GailInNM

I will make a few long term running updated on "Tiny" over the next few days.

First is the spark plug. 
Some time after 300 plus hours of running time I inspected and replaced the spark plug. The center electrode had eroded flush with the insulator. The electrode is 1/32 music wire. Also the ground electrode showed signs wear. Although I replaced it, it was still working fine.

I don't consider this amount of wear too bad. It's the rough equivalent of 12 to 15 thousand miles of driving and it seems to me that is about when I changed plugs on my 1940's Chevys.

Photos are the plug when new and at replacement. 
Gail in NM


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## gbritnell

Hi Gail,
Thanks for the update. I haven't run my Tiny since it was finished, just too many other projects going on. When you went to the lapped piston do you consider this to be one of the better performance improvements that you made? Mine runs good but it and seems to have good compression but it will only hand start on the rarest of occasions. 
George


----------



## RManley

very interesting results on the spark plug! Just out of interest, what insulator did you use? It seems to have withstood the heat well. Are you going to replace the electrode with piano wire again or try something else?

I imagine not many models get run for 300 hours so thats a very good test and a credit to the builder 

Rob,


----------



## GailInNM

First off thanks for the continued interest. Then, Last things first.

Rob:
The insulator is Corian. It is easy to obtain, very easy to machine and stands up well. Details of the spark plug construction are at:
http://www.homemodelenginemachinist.com/index.php?topic=8096.msg122619#msg122619
There is a PDF file attached to that post with construction details in the following posts.
I am going to continue to use piano wire for the center electrode. Tungsten would last lo9nger, but then it would just outlast the ground electrode. Tungsten is enough harder to work with that I think that I can make a spare plug with piano wire is less time than it would take me to make one with tungsten. Besides the insulator is beginning to show signs of wear also so every thing is beginning to wear out at once with the piano wire. It's just time to replace the plug. 

George:
In order of importance, the best performance enhancers on Tiny have been:
1: Lapped piston/cylinder.
2: Long taper needle valve to make fuel mixture setting easy. I have almost a full turn from full rich to full lean.
3: Replace main crankshaft bearings with FR156ZZ ball bearings. If you shop carefully they are available for
  US$ 1.00 to US$1.50 each.
4: Knurled 3/4 inch starting knob. I can start by flipping the flywheel easy enough, but when Arthur Ritius visits the
  shop it is hard to flip the flywheel fast enough with out it being painful. The polished flywheel is part of the problem as it is difficult to get enough friction. A finger cot to increase friction would probably help a lot.

If Tiny has fuel up to the fuel mixer, it will start first flip, using the finger knob, 19 out of 20 times I would guess. With the lapped piston and ball bearings it is very free. Turning off the ignition while running it will bounce back and forth on compression about 8 times after it quits turning over. 

I have attached some photos of my current piston and cylinder arrangement showing my lubrication set up. First off, a small oil cup was added to the frame and leads down to the cylinder spigot . It had to be off the center line to clear the cylinder mounting bold. The oil cup will hold about two drops of oil. The spigot on the cylinder has a groove in it for the oil to run into the 6 holes of 0.040 diameter that lead to the cylinder. When the piston is at BDC they match up with the wide groove in the piston which is 0.040 wide by 0.005 deep. Two additional grooves are near the top of the piston. They are 0.005 deep and just cut with a sharp pointed threading tool.

 I have played with different oils and what works best for me is "3 in 1" multipurpose oil. 10 weight machine oil seems to be too thick and air tool oil does not last long enough. I put the piston at BDC and put two drops of oil in the cup. Let it set for a half a minute or so to distribute and I don't need to oil again for 7 to 8 hours of running. This gets rid of almost all the oil in the combustion chamber so the spark plug and valves remain clean with only a little bit of carbon build up. The current piston is a bit longer to give me about 5.2:1 compression ratio. I had been running about 4.8:1. This helped the engine take a load better.

My Tiny is running at 2000 rpm in hit and miss mode, with hits about every 10 revolutions with no load. I judge the oil requirements by cylinder temperature, tested with my most reliable index finger. After running for 15 minutes or so to warm up, for the first few hours after oiling I can press firmly on the cylinder fins as long as I want with out feeling uncomfortable. After about 5 hours of run time I can feel the cylinder temperature start to climb a little bit. When it gets to where I feel uncomfortable after pressing on the cylinder for 15 seconds then it is time for more oil. This seems to be about 7 hours of run time. I measure my fuel and fill the tank with 5ml of fuel. Just after oiling I get about 1 hour 10 minutes on a tank. This drops to about 55 minutes when it is time for more oil. I can get longer run times by leaning out the mixture, but the engine does not take a load nearly as well and takes longer to recover from a load being removed. 

Hope no one got bored by my long winded update.

Gail in NM


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## spuddevans

GailInNM  said:
			
		

> Hope no one got bored by my long winded update.



Absolutely not!!! It is very informative. This little engine is on my "To-Build" list, so I am appreciative of any and all information by more experienced builders.

Thank you for sharing,


Tim


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## gbritnell

Hi Gail,
Not at all. This gives me a little more information to update mine when I get some of these larger hit and miss engines out of the way.
George


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## Swede

You've got to love the insane running time on such a small amount of fuel! I love these early petrol engines.


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## GailInNM

Thanks for the comments everyone.



			
				Swede  said:
			
		

> You've got to love the insane running time on such a small amount of fuel! I love these early petrol engines.



It is fun Swede. I is not without it's problems however. Because of the small annular passage for the needle valve any impurities in the fuel really cause problems. I pour my fuel from a 1 gallon can that I use for my lawnmower into a 500 ml bottle. Then I filter the fuel into a 100 ml bottle with filter paper in a funnel. The 100 ml is enough to rum for 20 plus hours. A semi-standard definition of a "drop" is 1/20 of a ml so this gives me about 35 to 40 seconds per drop. Since I am running in hit and miss mode at 2000 rpm and about 1 power stroke per revolution, then it's 120 power strokes per drop. So metering and atomizing the fuel without the adjustment being too sensitive was an early problem. Still it's fun and I would not have it any other way.

Early on, I put light springs on the hit and miss governor and ran it at an estimated 600 rpm. It got about 21/2 hours on 5ml of fuel then, but could not take a load like I wanted. Sounded nice though.

Gail in NM


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## kcmillin

Gail, I have a few questions I can't locate an answer to. 

What size electrode are you using? And are you using a sewing needle for the fuel mixer? I am currently using piano wire which I ground a taper onto with a sander, it is inconsistent to say the least.

Kel


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## GailInNM

Kel,

I used 1/32 music wire from the hobby shop for my electrode. Full details of my plug construction start at:

http://www.homemodelenginemachinist.com/index.php?topic=8096.msg122619#msg122619
An attachment to the first post at that address is a PDF drawing of all the assembly of the plug also.

I used a sewing needle for the fuel mixer. A #12 Sharps as I recall which is nominal 0.019 diameter into a 0.020 longitudinal hole in the spray bar. Details are at: 

http://www.homemodelenginemachinist.com/index.php?topic=8096.msg122597#msg122597

Also in the downloads section I put a chart of the size of various sewing needles. Supposedly for each number size the max diameter remains the same for various kinds of needles with the length of taper and overall length changing but I found quite a variation from brand to brand. So take the chart only as a starting point and then measure the needles you get.

http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item309

Gail in NM


----------



## kcmillin

Thanks Gail. I am trying to work out the kinks in my T-I4. I am using a .082" venturi at the moment, I am going to make a new barrel with a smaller venturi and an actual sewing needle instead of the home made jobbie I am using now. Your posts on the subject have been incredibly valuable.

 I am assuming that the sewing needle will have a very smooth surface, compared to the rough surface of the needle I am using now, which I am sure is causing problems. Sometimes it's perfect, then shortly after something happens. I do have a model engine fuel filter inline to keep the gunk out though, but some small particles may be getting through. 

Kel


----------



## GailInNM

Yes, the needles have a very smooth finish. Nickle plate as I recall. They need to be smooth to pass through cloth easily.

I had some erratic running due to fuel impurities but that is fairly well past now. I filter into a 100ml bottle from my stock gasoline. I use a small funnel and a disk cut from a coffee filter for filter paper. I used regular laboratory filter paper a couple of times, but it is very slow for even the coarsest grade. Everything seems OK using the coffee filter.

I use a modified syringe to transfer from the bottle to the tank. I had to modify the syringe as the standard syringe seal is not happy with gasoline. I turned a brass plug to press fit the syringe plunger and put a nitrel oring on the brass part. Now the syringe body swells with the gasoline after a few weeks and so it still does not work too well.

Gail in NM


----------



## GailInNM

Putting "Tiny" to Work.
A second "Tiny" Hit-N-Miss was built with a few changes to reflect what I had learned on the first one. Also the fuel tank was changed to fit the current project. A Gauge 1 locomotive. I could call this a scale model, but it would be a stand way far off and squint to be anywhere close to scale of anything. But the inspiration for the project came from a little industrial locomotive used in one of the Royal Armory shops in England. 

It is up to the point that I put it on a track today and ran for a little over an hour. So here are some preliminary photos of what is going on. I still need to put some clutch linkage in, a proper roof and a lot of other details.

There is a penny in the foreground of the first photo for scale.

I will be out of town for a week, so if there are questions there will be a delay.

Gail in NM


----------



## kcmillin

Wow, thats pretty cool Gail!! I hope you can get a video up when you get back.

Kel


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## GailInNM

There will be video when I get back. I tried some inside this evening, but the light was poor and the camera was very unhappy with the sharp exhaust bark as the track was on a ceramic tile floor. I am going to Utah to play trains and will run it on the outdoor 250 foot track there. Should take about 3 minutes for a lap. I will try to get some video there and if it is any good I will post it when I get back. 

Gail in NM


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## NickG

Absolutely fantastic! Never imagined I'd see anything like that!!! :bow:


----------



## GailInNM

I got back from Utah a few hours ago. Here is a very short video of the Tiny Loco on the outdoor track. There will be more to come later, but the card that they are on continued on to my daughters house when we unloaded. So it may be a week before I get them.
Gail in NM

[ame]http://www.youtube.com/watch?v=n3OMOXNS0ds[/ame]


----------



## gbritnell

Absolutely outstanding Gail. When you built this second engine did you use the hone method for the piston to bore fit again? What other changes did you incorporated into this 'Tiny' that you learned from the first?
George


----------



## GailInNM

Thanks Nick and George.

George:
For the cylinder I first bored the cylinder with a carbide boring bar leaving 0.0012 for finishing. Then I lapped the cylinder in two steps using a pair of expanding brass laps. The first was a roughing lap charged with 30 micron diamond and then finished with 10 micron diamond. Separate lap for each grade. 

The piston was turned 0.0002 oversize and then polished down to the fit I wanted using starting with 600 grit abrasive paper backed with a ground steel parallel. When it almost fit I switched to 1000 grit paper and finished with 1200 grit paper.

This is the same procedure I used on the first Tiny. Cast Iron was used for both cylinders and pistons.

The only design change of note was to increase the angles of the spark plug an additional 5 degrees both in the vertical direction and sisd to side direction. I also changed the hit-n-miss latch a little bit, but of course that was never detailed out in the build thread. The tank was also changed to better fit in the locomotive.

The rest of the learning was in how to fit the valves. On the cylinder head I left the spud that sticks into the cylinder about 0.03 long until after the valve seat clearance was drilled. Then I faced off the spud to length. his got rid of any chatter from the drill starting. The surface was then smoothed with abrasive paper on a flat surface leaving me with a sharp square edge for the valve seat. To seat the valves I made what looks like a valve seat cutter but with out any cutting edges. I used this to burnish the seat until I could see a burnished seat all the way around. I measured this with a microscope and it was about 0.002 wide max with a little bit of variation due to diameter variation of the drilled hole. The valves were polished as standard. I made three heads this way and the valves all seated with no leaks using the tester I had made up for the head. Extremely narrow valve seats are very helpful on these small valves.

Gail in NM


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## NickG

Stunning, I can't imagine the amount of interest it must create! :bow: Have simply got to make a Tiny IC!


----------



## kcmillin

It really Looks Great going down the rails Gail! 

I also like your method of making valve seats. Was this tool made from Drill Rod? How smooth was the 'burnishing' surface?

Kel


----------



## GailInNM

Thanks Nick and Kel.
Yes, it created a lot of interest. There have been a few gauge 1 IC powered locomotives before, but all that I know about used a model airplane engine and sounded like an angry bee. This one sounds right.

The burnishing tool was made at the same time as the valves. The valves were made from 1144 steel and so was the burnishing tool. With brass valve seats it should last a long time. The valves and tool were cut using a VBMT carbide insert with a 0.015 tip radius. This insert has a high enough positive rake that I could cut the valve stems with little tool deflection. I did cut the portion of the stem that never enters the guide during operation about 0.002 under-size so only a shorter section had to be cut to size to fit the guide. After cutting, both the valves and tool were polished a bit with 800 grit abrasive paper backed by a steel rule.

Gail in NM


----------



## putputman

Gail, I just saw your latest Tiny I.C. project. WOW!!! It is very creative the way you put it to work. I just love it. 
You have both of your engines running so smooth. 
I hope to get back in the shop come winter and maybe try something similar. You are a real inspiration to get me motivated.


----------



## GailInNM

Thank you Arv, both for your kind comments and for getting me started on the Tiny project.

I will be looking forward to seeing what you come up with.

Here are some more photos of the Tiny Loco working. As I did not have time to get any kind of couplers on it, I was pushing things around. The first photo is with 16 ore cars. Started with one and it did not slow it down any. Added a few more and finally got up to 16, which was all we had. Wheels on the Loco slipped a little bit when starting up, but was solid after a few feet. Not too supprising as I was starting up in the steam up area and the tracks have a lot of steam oil on them there.  Last photo is with a log disconnect. The log is real, cut from the branch of local tree. We had three log cars on at one time and the Tiny Loco didn't even know they were there.

Video with the ore cars to come in a few days.

Gail in NM


----------



## kcmillin

Wow, you are truly Working the little guy, that is awesome! Do you have any guess of the RPM of the motor while it is running with load?

Kel


----------



## GailInNM

Kel,
It's running about 2000 rpm in hit and miss mode. With the governor over ridden it get up to about 5000 but if I advance the timing and tweak it for high speed it runs about 8000. It is set up to take a load from idle at the 2000 rpm governed speed. No noticeable change in the engine speed when pushing the cars. I was concerned aoout power when working, but there is lots left over. The loco could use more weight as if you stop it the wheels just spin. Wheels are about 0.950 diameter on the tread and the gear ratio is about 7.5 to 1 from the engine to the wheels.

I got the video up loaded. It was taken with a very old camera so not the greatest of resolution.
Gail in NM

[ame]http://www.youtube.com/watch?v=WXAZ5OXJYHg[/ame]


----------



## cfellows

That's really cool, Gail. I've been thinking I need to build a vehicle of some kind to put an engine in. Getting tired of just watching them run!

Chuck


----------



## ozzie46

That is just so neat Gail.

 It is really powerful for its size.

  Excellent job.  :bow: :bow:

  Ron


----------



## Ram50V8

I just ran across this thread today and had to go back to the very beginning. I have spent most of the day reading, watching videos and looking at pictures. I :bow: to those who have built it an made so many custom mods to suite their own tastes. I am especially thankfull to Arv for coming up with such a wonderfull simple and adaptable design. Now I just have to start building my own version! 

 Darren M.


----------



## Groomengineering

Dangit Arv you got me....






I'm not sure if I should give you a karma or a neener...... :big:

Oh well, a karma to you and thank you for the great drawings. Thm: I'll try to keep everyone updated on my (slow) progress. :

Cheers

Jeff


----------



## steamer

That is really cool Gail! I love it!

Dave


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## GailInNM

Hi Jeff,
Welcome to the dark side. You will enjoy your Tiny. Mine has become my favorite demo engine. It will be interesting to see what changes you make to suit your tastes. I think there are about a dozen running now and they are probably all different. I will be watching your progress.

Dave, 
Thanks. The locomotive version has been a hit with all who have seen it. I am building a third Tiny for a follow on version of the locomotive. The original locomotive was very loosely patterned after the Woolwich Armory industrial locomotive. The new loco will follow the original a little more closely and be scaled up about 25 percent. Target run date is mid October.

My original tiny was beginning to show it's age. I lost even a rough track of time on it a couple of months ago and it was approaching the 500 hour mark then I think. Pulled it apart and tested the valves in the head after cleaning off some carbon. Every thing there looked good. Measured the piston and cylinder bores and had about 0.0007 difference. I have a lapped cast iron piston in a CI cylinder. I originally ift them at about 0.0002 clearance. A new piston was made and fitted this morning. It is back to it's old self and has about 5 hours on it today as I mostly did other things. Not quite as easy to start yet, but it will get there.

Could not reply earlier as a passing lightning storm took out my internet for most of the day and just got back online.

Gail in NM


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## Groomengineering

Hi all! A little update (told you it would be slow ;D )

Gas tank finished, crank holes drilled and reamed, ball bearings acquired for crank (cheaper than buying bronze  ), cylinder liner done..... And TING!! broke a tap in the bottom of the frame. :wall:

It's been stewing in a pan of Alum for about a week now on and off heat, at the rate it's going it could take a month.... scratch.gif

Started on the crank and if the weather cools off a bit I'll try to finish it up and get some pics.

Cheers

Jeff


----------



## tguckian

*GailInNM: I am a long time machinist and a short time miniature engine builder. Started with a Sterling engine and moved quickly to an IC 4 cyl plans from Burleigh Machine. Large jump it was. I am about 10% along with the parts, making the small ones first. Will takle the large stuff later, like in the fall when the garage shop cools down a little. Thanks for your help. Tom in Mesa AZ*


----------



## GailInNM

Tom,
Welcome to HMEM.  Although since you have a set of Kel's (Burleigh Machine) plans that lyou have been working on I assume that you have been lurking here for a while.  He used a modification of my spark plug construction in his plans for the Tiny 4 so you had seen that drawing before I pointed you in this direction from "Making mini sparkplugs." thread.

I have a Tiny 4 part way done but had to stop for a while due to health reasons.  Still not quite ready to resume on it as small parts a still a bit of a problem.

Don't be shy.  Start a thread on your build and if there is anything that any of us can do to help all you have to do is ask.  Sharing your work  is one of the best ways to keep entusiasm up.
Gail in NM


----------



## xander janssen

Hi,

After a few Stirling engine, I would like to build an IC engine (either the "tiny" or the "webster"). As I live in Europe, I'm currently converting both plans to metric.

To get some more insights, I calculated the compression ratio of both the "Tiny" and the "Webster" and they are ~2.5 times, which seems to be very low (compared to those of Jan Ridders' engines which are ~ 4.5).

Mayby I'm making a mistake here, so did anyone ever calculated the compression ratio of the "Tiny" or "Webster" before?

Thanks in advance,

Xander


----------



## gbritnell

Hi Gail,
Did you ever post drawings for the hit and miss mechanism?
gbritnell


----------



## putputman

Gail, I recieved a PM from XanderJanssen with the same question about the compression ratio. I never bothered to stop and figure the compression ratio as mine seemed to run OK as it was. You took your engine far beyond mine as far as perfecting the carbon piston, lapping the cylinder, and getting effciency on fuel, etc.. If you have the compression ratio he is looking for, would you answer his question on the forum. Perhaps other people would be interested also.

I am delighted that people are still interested and building this engine. I am also interested in your answer to George's question.

I hope & pray your health is still headed in the right direction.


----------



## GailInNM

George,
I never did a formal drawing on the Hit-N-Miss mechanics.  My implementation of Tiny was "a bit" different that Arv's original so changes would have to be made for the H-N-M function to work properly.  I will PM you about it and see if I have anything that will help you.
Gail


----------



## GailInNM

Arv,
Good to hear from you.  Things good here.  Vision continues to get worse all the time and really slows down building.  Recovery from the stroke is progressing nicely.  Some functions will never come back but overall I am doing quite well.

The compression ratio on my Tiny's (I have built several) is 5.2:1.  I played with it some in the early days and found that I could not tell any difference in operation from 5.0 to 5.3.

The final version has a cast iron cylinder with a cast iron piston.  They were lapped independently to 0.0002 clearance.  The piston has several oil grooves  0.005 wide and deep plus a spreader groove near the bottom to bring oil toward the head from the oil cup.  I only use about 1 drop of oil per hour now. 

I am working on my Woolwich locomotive now .  It is powered by a H-N-M Tiny. I will do a thread on it later after I finish detailing it some more.  Currently disassembled for anodizing.  Here is a video of it sitting at Idle waiting for the main line to be free. Idle is 3000 rpm with it hitting about every 12 revolutions.

Gail in NM
http://youtu.be/a-csJ3As7dc
[ame]http://www.youtube.com/watch?v=a-csJ3As7dc&feature=share&list=UUC8RZePnFk5KLNYzDoXI0lw[/ame]


----------



## AussieJimG

Hello,

I followed this thread with interest and have been trying (off and on) to build a Tiny. At present, I am having problems finding the best way to make the valves. 

I have tried turning them from stock (a couple of different ways) and making them by silver soldering buttons onto the stems. Neither way seems quite satisfactory. I don't think I get the required accuracy.

Now I wonder how the experts did it. Any advice?

Jim


----------



## GailInNM

Jim,
Not that I am an expert, but here is how I make my valves. The first thing to recognize is that the entire stem does not have to be made accurately. The part of the stem that sticks through the head when the valve is fully opened can be a little bit under size as it never engages the the valve guide when running.  Likewise the portion of the stem that is in the pocket when the valve is fully closed is of no concern as it can never reach the valve guide. So it can be under size or oversize a bit without affecting things.  

In the case of "Tiny" valves this only leaves about 3/16 of an inch, about 4.5 mm, that has to fit the valve guide.  This is a lot easier than trying to turn 3/4 inch (20mm) or so to a precision fit with such small diameter.

Here's how I made mine for "Tiny".  I started with 1/4 inch diameter 1144 steel.  I like 1144 for small valves as it cuts easily with a good finish.  I use a VBMT (35 degree diamond shape) carbide insert with a 0.015 tip radius.  I have a high speed lathe so I run it about 3500 RPM.  That is not critical but is does speed things up.

Two things that are important are keeping the stock projecting from the chuck or collet tothe minimum to make the valve and that the cutting tool is on center line.  I use a dial indicator to set the tool height. Because of small diameter of the stem a few thousandths high or low is enough to ruin your whole day.  

The compound on the lathe is set to 45 degrees.  My collet closer nose sticks out a little bit so it is easier to get the cutting tool into position than it would be with a chuck, but is possible with a chuck.  Remember that a prime objective is to keep the minimum of stock sticking out of the collet or chuck. When this is not possible, you can start with a larger diameter stock like 3/8 or 1/2 inch and it it stick out some.  In any case careful positioning of the tool post on the compound will be necessary. 

Out of time tonight.  I will detail the actual machining in the next post. 

Gail in NM


----------



## GailInNM

Time to make some chips. By this time I know how much of the end of the valve stem can be undersize because it will never engage the guide in operation.  In my case on "Tiny" it is about 0.275 to 0.350 inch depending of if it is an intake or exhaust valve.  Face off the end and zero what ever Z axis measuring devise you may be using.  Rough cut the undersize portion of the stem.  As my stem's working diameter will be about 0.078 inch  diameter I cut it to about 0.085 diameter then change tools and put the spring retainer groove in. I sometimes put the groove in later holding the valve stem in a split collet.  Back to the turning tool and finish turning to 0.075, about 0.003 undersize. I use this turning operation to calibrate the cutting tool by measuring the diameter and setting my DRO or dial to match the diameter. 

Now I turn the rest of the stem to my 0.078 nominal dimension.  It should fit in the valve guide but can be a bit of a stiff fit as it will be polished down to about 0.001 loose in the guide.  After the stem is turned I cut the valve face using the compound.  I lock the carriage to keep any  side force generating by the compound feed from making the valve face rough. I make several passes with the compound to eliminate as many tooling marks as possible then unlock the carriage and turn the head diameter long enough to allow for cutting off the valve.

With the turning operations complete, I polish the working portion of the valve stem and the valve face with silicon carbide abrasive paper, commonly known as "wet or dry", with some light oil on it.  I start with 400 grit until the valve stem fits smoothly in the guide and the polish a little bit more progressing through 600, 800 and 1200 grit grades of paper.  To polish I cut a narrow strip of abrasive paper and back it with a strip of flat metal.  I normally use a 5 inch steel machinists rule. EVERY TIME you test fit the valve in the guide you must clean it very well so no abrasive paste from the polishing operation gets in the guide.  If any abrasive becomes embedded the walls of the guide it is there forever.  The only way to remove it is to ream the guide hole larger.

When I cut off the valve from the stock I normally leave it a little bit long and the finish it to length in a collet or make a split collet to hold it in a chuck.

Gail in NM


----------



## AussieJimG

Thanks Gail, sorry for the delay in responding, I have been in hospital for a few days (I am sure you understand the situation).

Your advice makes good sense and I will give it a go when I can get back into the workshop. Thank you again.

Jim


----------



## naijin

Very nice quote in russian, I believe the same applies when translated into english!! Ha1 Ha!....... well done


----------



## rac37

IMG_0043.jpgMy Tiny IC
Completed a few days ago. Really enjoyed the build as it was quite a challenge for me. Thanks PutPutman for all the plans and info.
Now to try and make running video.

bob


----------



## GailInNM

If the insides are anywhere as nice as the outside I am sure that it runs great. Great build.  Thm:Thm:
Gail in NM


----------



## rac37

Thanks Gail, 
 I've enjoyed following a lot of your posts and have gained a lot of insite from them. My Tiny is pretty much stock build I still have to use electric start may need to fine tune the intake valve spring. Using 87 octane gas and a little wd40 oil. So far cooling not a problem. Recently replaced one of the crank bearings and went with a viton o-ring. Yep I screwed up the original bearing a few too many thou. big.

bob


----------



## awJCKDup

Nice build Bob, built one myself and love the little guy. Best free plans I've ever gotten. Waiting for the video.


John


----------



## putputman

Bob, that is a beautiful engine. I am delighted to still see some interest in the Tiny I.C.

You, Gail, John, and several others have taken my design way beyond what I ever imagined it would be.


----------



## rac37

Thank you Arv for the compliment and for posting the plans for this neat little engine. I've had several runs with it and each time seems to get better. Really an enjoyable challenging build. Now guess I need to find video software to post a video of it running. Thanks to all posters on this thread a lot of great ideas and guidance.

bob


----------



## rac37

Short video of Tiny attempt to start and short run. third attempt. Sorry for hand in the way gotta work on my videography skills next.

[ame]http://youtu.be/VdYvExRV3Jc[/ame] bob


----------



## Graemep

HI all tiny builder I just finished my tiny and here is my take on this wonderful engine .Many Thanks to Putputman for the excellent plans and build log .Also thanks to Gail for all his effort and willingness of information to help builders like myself to build tiny .


----------



## bazmak

Theres me thinking i was an engineer then i read this thread
and sink into deep depression.If only i had the skill and eyesight
Congratulations all you Guys


----------



## rac37

Wow, nice looking engine Graemep. Did you use conventional alum. piston with o-ring? Really a neat little engine.

bob


----------



## GailInNM

A very well executed "Tiny" Graemep. Looks great. Thm:Thm:

Baz: Remember that skills come from trying things you have never done before.  Eyesight can be a problem but can be worked around if you work at it. I am functionally blind in one eye and am way below the minimum driving requirements in the other with the best corrective lens available. I just push myself and work slowly. 

Gail in NM


----------



## Graemep

Thanks every one this was my first IC engine . It was a great little engine to build as there was so much information given on this thread especially all the information and posts by Gail . 

Bob: Thanks your little tiny looks excellent to and No I did not use an o-ring I use Gail's method of cast-iron piston honed to fit the bore (no rings ) .

Graeme


----------



## putputman

Graemep, Congratulations on building your first IC engine. Tiny I.C. is not an easy engine to build. I'll bet we see a lot of I.C. engines out of you in the future.

I really like they way you displayed your engine on the piston. Is that lever on the back side for adjusting timing?

Looking forward to a video.


----------



## Graemep

Hi all, here is a video of the first run of my tiny IC (I hope).

 Thanks Arv for your reply and yes the lever is for the adjusting the timing

 [ame="http://www.youtube.com/watch?v=C2K6bineCDs"]www.youtube.com/watch?v=C2K6bineCDs[/ame]



 Graeme


----------



## AussieJimG

Nice one Graeme.

Jim


----------



## errolf2

I have just finished building the Tiny IC and as yet I have not been able to get it to run. I used aluminium for the head and pressed in stainless steel valve inserts and lapped them to 2mm stem diameter valves. I have the exhaust valve starting to open at 35 degrees before BDC and closed at 5 degrees after TDC, the ignition timing fire at about 5 degrees before TDC but is easily adjustable. As you good people have running engines I would appreciate your comments.
Regards
Errol


----------



## rac37

Errol,
 Nice looking engines you have made. I too just completed a Tiny and a Powerhouse engine this winter. I am sure you probably verified spark, compression, and fuel draw. My exhaust valve is pretty well closed by tdc but not sure that would make much difference. I did have to adjust my intake valve spring a few times b4 it would run reliably. I am running coleman fuel with a Viton ringed alum. piston. I believe I advanced the timing approx. 20-30 deg btdc and she seems to like that.
 Question on the Powerhouse, is that a pmr dynamo? I am thinking to add one to mine.
 Good luck and looking forward to your videos.

 bob


----------



## errolf2

Hi Bob,
Thanks for your kind words and yes it is a PMR Dynamo however instead of using the screws supplied I made 2mm studs and Brass domed nuts to be more authentic. I think this makes the unit look more aesthetically pleasing the only disadvantage is the time taken to make them.
I have made a test jig to test the valve seal on my Tiny IC and have discovered at 150 psi I have a slight leak so I am in the process of making another set of valves and seats. What diameter wire and how many coils did you use for your Tiny IC inlet spring?

Best regards and thanks for the prompt reply

Errol


----------



## GailInNM

Errol,
Nice work on your engines.

I have built several Tinys and here is what I used for springs.

My intake spring is 8 turns of 0.009 music wire wound on a 0.078  mandrel. Finished OD is 0.115. Free length was set to provide about 0.05  compression with the valve closed.

My exhaust spring is 8 turns of 0.012 music wire wound on 0.078 mandrel. Finished OD 1s about 0.115 also.
I started off with 0.011 wire, same wind, but changed it as I thought I was getting some valve float at high RPM.

Gail in NM


----------



## robcas631

Neat engine!


----------



## robcas631

Bear it's amazing!


----------



## robcas631

Great work Kel!


----------



## gus

putputman said:


> This is about all I have at this time. There have been a lot of downloads but I have no idea if anyone is building this engine. If anyone finds errors in the drawings or needs additional information, please feel free to contact me.
> 
> I do plan to upload the complete package of notes & prints once they are updated to correct any mistakes or omissions. This will be within the next month.
> 
> If you are pleased with post and information provided, a karma would be very much appreciated.
> 
> Best of luck & I hope to see some new Tiny I.C. Engines on HMEM.
> 
> Arv (putputman)



Hi Arv,

I am impressed by your tiny engine. Just Downloaded plans. Right now building the Nemett-Lynx Engine. After this engine I am tempted to build your engine.
Alas. So little time and so many engines to think of building. My luck with two stroke engines is bad. Two stroke engines look simple to make but very unforgiving. I do OK with 4 stroke.
Thanks for the engine plans.


----------



## AussieJimG

gus said:


> Hi Arv,
> 
> I am impressed by your tiny engine. Just Downloaded plans. Right now building the Nemett-Lynx Engine. After this engine I am tempted to build your engine.
> Alas. So little time and so many engines to think of building. My luck with two stroke engines is bad. Two stroke engines look simple to make but very unforgiving. I do OK with 4 stroke.
> Thanks for the engine plans.



I still have all the discarded Tiny heads for you to use a sinkers Gus, I will bring them to Melbourne for you. 

And then you can add your own. 

Jim


----------



## gus

AussieJimG said:


> I still have all the discarded Tiny heads for you to use a sinkers Gus, I will bring them to Melbourne for you.
> 
> And then you can add your own.
> 
> Jim



Hi Jim,
Please put the sinkers into a small paper box and sign your autograph.
Will use sinkers at the latest extreme spot given by old friend. 8 strikes and all six snagged and only two good size grouper came up.Here is the first fish.


----------



## putputman

Gus, thanks for the compliment on Tiny I.C.  It was a fun build for me & I still run it now & then.
There have been many people that have built the engine, most of who have added their own modifications and improvements. Each one is sharper than the last. I'll be following your build to see your mods. 
Good luck,
Arv


----------



## barnesrickw

Good looking engine. 


Sent from my iPad using Model Engines


----------



## KLG

putputman said:


> Gus, thanks for the compliment on Tiny I.C.  It was a fun build for me & I still run it now & then.
> There have been many people that have built the engine, most of who have added their own modifications and improvements. Each one is sharper than the last. I'll be following your build to see your mods.
> Good luck,
> Arv


Hi All,
I am building my putt put at the moment. I have trawled through all the posts (and there are a lot). I have incorporated the ball bearing crank, bushed both ends of the conrod with bronze and used bronze inserts for the valve seats and guides.I have also incorporated the hit and miss mechanism that Gail from NM designed. Gail kindly gave me enough info regarding the disposition of the fulcrum and lever points and I have redrawn all this to suit my own tooling and material availability. They may be of interest to others so I have enclosed them along with images of my trial assembly. The other mod that I did was to use the thick valve stems using the retaining collets but I reduced the diameter of the stem in the port area. I am now ready to do all the final finishing so maybe another month or so will see the project finished.
Cheers,
Kerry from OZ 





















View attachment Kerry's Put Put drawings.pdf


View attachment Kerry's Put Put drawings2.pdf


----------



## GailInNM

Looks very nice Kerry.  I will be watching for the first pops. Your mods all sound good.

I am getting started on a few more "Tiny"s. They are too much fun putting them to work power things.

Gail in NM


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## AussieJimG

Good onya Kerry, that's a nice looking engine.

I really must have another go at a Tiny. 

Jim


----------



## Swifty

Looks like I will have to put one on the "to do" list.

Paul.


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## Stefan-K

Hi together
At the moment I´m building my Tiny and it`s  almost at a stage to let it make the first few pops. But i have a question left over. How do you secure the Piston pin and prevent it from making scratches into the cylinder wall? There is no room left inside the piston, cause everything is so "tiny"

Stefan


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## GailInNM

Stefan,
Looking forward to your first "Tiny" pops.

I just make the piston wrist pin about 0.005 inches shorter than the bore and then slightly dome and polish the end of the pin in the lathe. The pin is left to float in the piston. 

I use cast iron piston and cylinder and lap them to fit with no ring. The pin is 1095 steel.

 I have one Tiny with many hours on it and no visible scratches in the mirror lapped finish of the bore.

Gail in NM


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## Stefan-K

Hi Gail

Well i`m glad to hear that leaving the pin floating in the piston is no Problem here. If it works for you, it`s goin`to work for me too.  In other engines i used to hold the pin in place with a little M1.6 or M2 screw depending on the size of the piston.
Because i converted the Plans from putputman from imperial to metric i just found out that my connecting rod is too short. My mistake! So i have to make a new one. I´ll keep you updatet...

Stefan


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## Stefan-K

Hi

A little update on the progress. The new Conrod is finished and i made a new piston with a tighter fit as well. It is about 0.04 mm (or 0.0015 inch) smaller than the bore. Tried to start the engine but no success! It sure popped a few times but it didn`t run. I found out the problem is the Sparkplug. It sparks outside the engine with some "blackouts". And that was getting worse. At least it sparked only sometimes. Seems to me that the plug has an internal short circuit somewhere. Maybe the corian insulation is too thin. Have to make a new one........

Stefan

Attached you find some pics.....


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## AussieJimG

Maybe cleaning the spark plug with clutch and brake cleaner would help. It only takes a little bit of dirt to create a track on the plug.

Jim


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## GailInNM

Stefan,
Looks great!
I had one plug that failed after about 10 hours running, as I recall.  It would spark OK outside the engine.  I have a tester made up that I can pressurize
the plug with with shop air to about 40 PSI.  It has a acrylic window in it so I can view the gap.  It would not spark when under pressure.  I assume that there was a thin crack in the insulator within the body of the plug.  

This was an early plug and the center electrode was a tight fit in the inslulator so I suspect that it cracked, or started to, during assembly.  All my later plugs I made with an easy fit between the center electrode and the insulator and got a good epoxy bond between them.  Never had a problem with any of them.  A friend has one of my early "Tiny" engines in a locomotive and the spark plug has failed.  He has about 30 or 40 hours on it.  He is sending me the plug to examine.  I had given him a spare plug and it cured the problem he was having. He is in Canada so I have not seen it yet.

 I am getting ready to make some more plugs for some more engines to go in two Gauge 1 locomotives. Engines are about 1/2 done and am drawing the locomotives.  The locomotives are Baldwin Mechanical trench locomotives as were used in World War 1 for moving supplies behind the lines on 2 ft gauge tracks.

Gail in NM


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## putputman

Stefan,
I am curious about that third gear under the crank shaft. I don't recall seeing a set up like that before. What is the purpose of that gear.

Looking forward to seeing another Tiny running.

Arv


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## Stefan-K

Hi Jim , Gail and Arv

Cleaning the Plug with brake cleaner was the first thing i did, but it didn`t help. I remember, as i turned the corian insulator, that the thinnest part (2mm) broke off. I glued the parts together hoping it might work. But as Gail already said, a little crack in the insulator will allow the High Tension to jump over at that point. We are talking about 5 to 15 thousand volts or more, depending on the ignition system and coil you are using. I am using a selfmade CDI system which runs on 6 volts and puts about 400 volts on the primary side of the ignition coil and that leads to an output of aproximately 15 K volts. Once it jumped over it will create a very little path of carbon in the crack from burning the material. And this will conduct the electricity even better. That explains the behaviour of the sparkplug. I´m sure that this was the reason for the failure.
Arv, you asked for the reason of the third gear. Well, i use it for the ignition timing.  On the inside of the gear you can see a narrow ring of Plastik (Delrin) wich contains the small magnet. I set the ring on the axle and clamp it on with 2 little screws. So i can set the timing where ever i need it. I attached 2 Pics to make it more visible. I wanted to make smaller gears, but i have only one set of Modul gear cutters (m 0,75). And these were the smallest gears i can make with them.
Hope the new Plug works as expected....
Keep you updated.....

Stefan


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## Stefan-K

Hi together

I have good news.

I finished the new Sparkplug, put everything tentatively together and gave it a try. I don`t use a liquid gas carburator, cause they are difficult to build in these small dimensions. And they often make problems. I use a vapour carburator instead.
What can i say, It runs. I´m so happy. All the hours in the shop pay off when you see it run the first time.

I attached pics from the new sparkplug and try to upload a video of the running Tiny. 

Here´s the video link: http://youtu.be/-TvEvwgvQxs

Here`s  another link about testing the new Sparkplug: http://youtu.be/nn1kUhR41ko

Stefan


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## AussieJimG

Congratulation Stefan, it runs well.

Jim


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## putputman

Congratulation Stefan, another great little runner. This is the first one I have seen use a vapor carb. That should solve the problem of standard carbs vapor locking from too much engine heat transferring to the carb. If you get a chance could you show photos of the vapor carb along with some dimensions. I think I would like to try it on my engine.


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## Stefan-K

Thanks a lot.

The Vapor Carb i used for the Tiny test run is from another engine. I attached  some Pictures. The dimensions i used here: The Glass tube has an inner diameter of 22mm and 24 mm outer dia. and is 80 mm long. it is glued with a loose fit to the aluminum side walls with Loctite 648. On the right side is a 5mm brass tube for the air inlet. The air is sucked in and goes straight down to the surface of the gas.  On the left side is another 5mm brass tube which goes to the engine via an "extra air" valve to adjust the mixture. The dimensions are not critical at all.  You can even use a small jar to test it. I found most of my information on Jan Ridders website, who had the idea. Here`s a video link about the Vapor Carburator:[ame]https://www.youtube.com/watch?v=xWBWhRZiZ9E[/ame]

And here is the link to Jan´s website with the Carburator.:
http://ridders.nu/Webpaginas/pagina_benzinedamp_carburateur/dampcarburateur_frameset.htm

He will send you a free plan if you ask him for it via email.

Since i`m using the Vapor carb i never had any Problems with fouling or wet Plugs.
Hope this helps

Stefan


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## Stefan-K

@ Gail
I´m just watching the pictures on post #128. The neat exhaust flap you made ! I like it very much and want to build one for my Tiny. Can you please give me an idea on how you made these parts?

Stefan


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## GailInNM

Stefan,
I thought I had some detail photos of the exhaust flap posted but I mayo not have.  I have a set of parts here of one for an upcoming project that I can photograph and post but I won't have time to do it for a week as I have house guests here for a while.  I can include some notes about it then.

Your Tiny looks and sounds good.  Congratulations on a successful build.
Gail in NM


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## Stefan-K

Gail

That would be nice. Thanks a lot. I still have a lot of work to do on the Tiny to make it look good. The exhaust flap is one of the latest things i can do.


Stefan


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## GailInNM

Stefan,
Here is a quick JPG of the parts drawing with just elementary dimensions.  Just make the operating arm so the flap can not open enough to stay open.  Flap part needs to have enough weight to be self closing.  I had to adjust the stop part of the arm a little bit to get the most pleasing action.  

If you need more information let me know.
Gail in NM


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## Stefan-K

Hi Gail

Thank you very much for the nice drawings. I appreciate sharing the drawings and i`m sure they will help me a lot. I´m just brooding here about how to design the Tank/Vapor Carb for the Tiny. Have to keep in mind that the Carb needs about 15 to 20 cm² (gas)surface to work and vaporise enough gas while the air flows through it. So the minimum size is limited. I wanna use glass to see the action inside but keep the focus on the running engine. I have one design in my mind that i will try to draw and post it here to see what you and all the others think about it.

Keep you updated.....

Stefan


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## Stefan-K

Hi
Here's a little update on the progress. I decided to build the Tank  and post a picture  rather than drawing it first. I also finished the exhaust with the flap.  These little parts took me almost a day to build them. 
Stefan


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## GailInNM

Looks good Stefan. You do nice work.
 Gail in NM


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## GailInNM

Stefan has finished his very nice model of Tiny and the finished model is shown in the Finished Projects section with more photos and video.  Sample photo shown here and the link to the thread showing the rest is here:

http://www.homemodelenginemachinist.com/showthread.php?t=24158






Very nice Stefan.
Gail in NM


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## GailInNM

I was just up on  YouTube to answer a comment on the video of the first TINY that I built. It is amazing how much attention the Tiny's  have attracted from the general public.   My first video has over 70,000 views and is still plugging along at about 500 views per month. And, there are a lot of other videos of Tinys in a variety of configurations from other people on YouTube and other places.

Thanks to Arv (Putputman) for getting this whole thing started.
 Here is a link to the video of my first Tiny.
https://youtu.be/mLn7xG8vuPQ
Gail in NM


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## AussieJimG

Stefan-K said:


> Hi Gail
> 
> I´m just brooding here about how to design the Tank/Vapor Carb for the Tiny. Have to keep in mind that the Carb needs about 15 to 20 cm² (gas)surface to work and vaporise enough gas while the air flows through it. So the minimum size is limited.



That is a beautiful engine Stefan and I like the carby too. Where did you get the information about the required surface area? Is it related to the swept volume of the engine?

Jim


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## Stefan-K

Hello Jim

Thanks for your nice comment.   I have all my information about the Vapor Carburator from Jan Ridders Website. I think he invented the principle of this carb. Here is the link to his website:   http://ridders.nu
He lives in the Netherlands and is a very nice guy.  You can see many videos of his engines running with this carb. He explains the vapor carb in detail on this site:
http://ridders.nu/Webpaginas/pagina_benzinedamp_carburateur/dampcarburateur_frameset.htm   The site is in dutch and english language.

Many greetings Stefan


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## AussieJimG

Thank you Stefan, I had seen most of Jan's site before but not that section. 

Jim


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## MrTin

I have just been put onto this little engine, by a guy on the English Model Engineer forum.
I have only a Peatol lathe (Taig) with a vertical slide, I have no milling machine, but want to build an IC engine.  If the base of this engine can be done using my limited gear, I could do it.
Can somebody explain if I can do the milling for this engine on my Peatol/Taig.
If so, I can crack on.

Cheers,
Martin


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## GailInNM

Martin,
The frame is the only thing that is likely to give you any problems. It is 2.6 inches long and you only have travels of one and a half vertical and one and three-quarter inches horizontal. I think you could do it but you might have to re-clamp a couple of times to cover the areas required. The sides of the frame could be cleaned up okay if you use a fly cutter, very gently, so you could cover the entire area.

Another alternative, would be to build an air cooled version. I have built a number of the air cooled versions and the frame on them is only 1.687 long. It does complicate the cylinder a little bit as it then has fins to cut instead of being a simple sleeve, but this is offset by not having to machine the water hopper on the frame. Although I made a number of other changes in my engines, all the other "TINY" parts are interchangeable with the different frame and cylinder. I think I moved the fuel tank mounting holes a little bit to accommodate a slightly different fuel tank that is trivial. If you wanted to go with an air cooled version I can send you my frame and cylinder drawings.

Gail in NM


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## MrTin

Gail, that's very generous of you and I would appreciate them.
I wondered if I could make the frame in brass, with silver soldered joints. 
Could the engine still be completed as a water cooled one if I did that?  Kind of half and half?
But I think, as you said, the frame could be done carefully, by reclamping for the milling.  I was even thinking that the cavity could be drilled out and filed.  Most of my brass modelmaking/patternmaking work has been filed to shape.  I'm used to it!
I do like this Tiny engine, but have also come up with a typically crazy idea of 4-stroking an existing 2-stroke.  I have a pair of Merco 61s that I got for a tenner at a dog show!. One is fine. The other, well, I reckon a new head with valve gear belt driven from behind could be an interesting design challenge with everything doable on the small machine.  I will go and dig one out tomorrow.

But I do think the Tiny could be a first attempt, so I would indeed like your plans, Gail.

I will PM you my address.
Cheers,
Martin


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## GailInNM

Martin,
I emailed you the appropriate drawings earlier this evening.

I can see no problems in fabricating the frame out of brass and silver soldering it together. Actually, I think that if you used a few small brass screws to hold the parts together that it would be perfectly solid enough even if it were soft soldered. If 3/16 or 5 mm brass were used for the load bearing components the additional weight would help dampen out vibrations at higher speeds. They are not bad as it is, but the engine does try to walk around a little bit if you open it up to where it is running above 5000 RPM. I certainly would not be apprehensive about a build up frame and tank/base.

Keep us posted about your build. I am always interested in "Tiny's".
Gail in NM


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## MrTin

Gail, that is very encouraging.
And very kind of you to send me the air-cooled mods drawings, which have arrived this morning.

I'd be likely to have more luck silver soldering the  brass frame together, than setting it up for drilling and tapping for screws.  I have never had any luck getting drills to go where I want them!  I even had an optical centre punch, but lost the acrylic optic bit.  Whereas, I spent many years making brass patterns, all silver soldered.

Many thanks for the Tiny drawing mods and the encouragement.
Cheers,
Martin


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## Jonathan_M

Dear All,

I'm planning to build a Tiny over the next few months with the aim of using it to drive an electric generator that will be fitted to a 16mm scale garden railway loco. It will be air cooled, and built with the piston vertical in order to have a smaller footprint in the loco. I have made a start by drawing the engine in Onshape, using metric units. This has meant converting and then rounding where possible in order to give easy to use dimensions. Below is a screen shot of the finished engine in OnShape.







I haven't included every component, but all of the key parts for checking the alignment and dimensions are there. I have made the model a public document, so if you are registered with Onshape you should be able to open it. The camshaft, pushrod and rocker arrangement doesn't work when you turn the crankshaft, as Onshape doesn't have a cam or tangent mate at the moment. However, just drawing and assembling in 3D was a really good learning experience, enabling me to get the rocker arm length right, the crankcase design resolved and the pushrod and inlet valve lengths finalised.

https://cad.onshape.com/documents/56bc5928e4b0c3373eb7a6c6/w/867b8d8dd751a285e55290ba

One thing I have noticed is that with the piston design as published by PutPutMan, the skirt projects below the bottom of the cylinder at bottom dead centre. Something tells me that this isn't right.

GailinNM has already been of great help to me with lots of advice and provision of his air cooled sketches and I'd like to publicly thank him for sparing his time to help me.


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## 10K Pete

The piston skirt extending at BDC is quite typical of H&M engines and is
correct for the Tiny.

I love the concept of your project; a Tiny Generator for a rail road! Why not
extend the idea and use it, or a larger version, for the prime mover??
Cool!!!

Pete


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## GailInNM

Jonathan,
Sorry to be slow in responding but my Internet has been acting up for a few days so I haven't been doing any posting. But better late than never welcome to HMEMand please join in the fun with your continued posting. 

Your drawing looks great. I went to the Onshape site and played around with it for about half an hour. It was lots of fun. Thanks for posting it and making it public. It looks like you're off to a very good start.

Yes, the piston does stick out a little bit from the cylinder at bottom dead center. This worked out to my advantage on the first lapped piston versions that I built as I could dribble oil on the piston to lubricate it. Later I added an oil cup to the cylinder and the oil distribution groove on the piston though that was not necessary. The piston length could be reduced a little bit but like Pete says it was a common practice on full-scale hit and miss engines for the piston to protrude a little bit so I just left it that way. With my cast-iron piston and cylinder I only need about one drop of oil in the oil cup an hour for lubrication and I use no oil in my fuel.

I am currently running in two more of the hit and miss Tiny's that I recently completed. In the hit and miss mode governed at 3000 RPM they both get a little over three hours of run time on 9 mL of gasoline. With the hit and miss govenor disabled they peak out at a little over 6000 RPM. With the fuel mixture richen up a little bit to reduce the RPM to about 5000 they get about 35 minutes on 9 mL of fuel.

Gail in NM


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## steve-de24

Gail, I have a question about the design of the Tiny that I think your extended running can answer. Have you had any problems with the unusual big end bearing split line design? I'm thinking of having this little engine (an air cooled version I think) as my next project, I've never done a 4-stroke sparkie before so a lot to learn if I take it on. Regards, Steve.


----------



## GailInNM

Steve,
I have had no problems with the big end on any of my Tiny hit and miss engines, even on the ones that have a lot of hours on them.

The big end does open up a little bit but not enough to cause an audible knock or any problems in running. About the same amount as a 2.5 cc commercial glow engine gets after 50 or 100 hours of operation. I think most of it is just flattening out the machining marks left by the reamer when I ream the big end.

My construction is the crankshaft is made of 1144 stress proof steel with the crank pin well polished. The crankshaft runs in ball bearings for support. The connecting rod is made of 2024 aluminum which has similar wear characteristics to Dural which was used on many commercial two-stroke model airplane engines.

For lubrication I use a full synthetic SAE 0-20 motor oil. I put a drop on when assembling and then put a drop on whenever I think about it, probably every 20 or 30 hours of runtime.

I use that oil because it has been the only thing that I have found that will not gum up the valve stems because of the high head temperature. I tried a variety of regular motor oils and instrument oils and they all would cause the intake valve to stick after 10 or 20 hours of operation. with the full synthetic oil I have never had a valve stick.

Keep us posted on your build. Always interested.
Gail in NM


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## grapegro

Hello Gail,
               I use fully synthetic oil on all machinery I have, I find it very good on my lathe,drills and mill in stopping rust in the cooler months. It sticks well, spreads well and lasts well.
Norm


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## steve-de24

Gail,
Thanks for taking the time to reply and the reassurance with the big end design. Your tip regarding the oil you use is filed away for later. I will need to source some higher strength steel and aluminium for the crankshaft and con-rod but that will give me a good excuse to attend one or two of the model engineering shows we have in the UK. Again thanks for your interest.
Regards, Steve


----------



## GailInNM

Norm,
Thanks for chiming in on the synthetic oil. It really solved a problem for me with the Tiny valves. Rust is not a real problem for me here in the high desert Southwest US. Typical humidity here is in the 10 to 20% range. You probably get more precipitation on a wet weekend than I do in a year.

Steve,
The crankshaft does not need to be a high strength steel, but rather one that works easily. I use 1144 because it is easy to turn and get a good finish on and the fact it has no tendency to warp when cutting the off-center crank pin. I have made a lot of similar cranks out of 12L14 leaded steel which is roughly the equivalent to your EN1A. They often times worked a little bit when the crank pin was turned but they were easy to straighten with hand pressure in the lathe using a dial indicator. 12 L 14 also tends to rust more than the 1144, but if you read my note to Norm you know that that is not a problem for me.

Any fairly hard aluminum should work well for the connecting rod. I think the 2024 that I used is probably one of the best but it was also used because it is very easy source in the US. I don't remember the UK equivalent for it but as long as it is not a real soft grade I wouldn't worry too much about using anything that is available unless you plan to run your engine for long periods of time as I do.

Gail in NM


----------



## steve-de24

Gail, thanks for the info. I have some leaded EN1a so that's my crankshaft material sorted (although I'm a bit reluctant to eliminate reasons why I 'must' attend model engineering shows this year.....). 
The UK grade of aluminium equivalent to 2024 is HE15 which is approx. 50% stronger than HE30 which is equivalent to your 60xx grades.
Regards,
Steve


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## gbritnell

While I had some spare time I thought I would build an air cooled Tiny. I will be incorporating some of the modifications that others have made along the way like using ball bearings for the crankshaft. I have trouble fueling my Tiny so I lengthened the base by .100 and moved the filler back the same amount. I pondered how to mount the cylinder without just pressing it into the base so I came up with threads. The thread diameter splits the existing metal wall on the drawing so it comes out darn close to .50 inches. The thread count is 40. I machined the base to the overall dimensions then chucked it in the 4 jaw chuck and picked up the center of the cylinder. I drilled and bored the hole then threaded it. The cylinder is made from Durabar iron and the threads cut very nicely. I will snug it in place and then lay out the centers for the head mounting screws. This way everything will be lined up. The plan for this one is to mount a hit and miss mechanism either like Gail's or some concoction of his and mine. 
gbritnell


----------



## steve-de24

George,
Thanks for sharing the modifications you are making to the basic design and your build photos.
You've grabbed our attention.
Steve


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## gbritnell

The engine is coming along nicely. Since last posting I have the crank, rod, piston and complete head finished which will be shown in the posted pictures. 
The rod is made from 6061 aluminum for lightness. I deviated from the drawings by making the throw bore bigger to accept split bearings. I found that on my other Tiny the rod journal wears quite a bit with the high rpm. 
The piston is made from aluminum also. I eliminated the O ring and lapped the piston to the bore. 
The head is made from iron and the valves are W-1 drill rod. I used the same procedure for the head as I did on the first engine. I left extra stock on the top surface and then using a plug type cutter made from drill rod I cut bosses around the valve guide holes giving a little more support to the valve stems. 
I had modified the spark plug entry angle on the first engine and did so on this one. 
Now comes the 'Tiny' work!
I mentioned in my last posting that I was going to use a combination of Gail's mechanism and some of my own design for this engine. 
Gail was gracious enough to supply me with some extra parts that he had made for his governor so I started there. I slid the spool and flywheel onto the crankshaft then held the centrifugal arm and weight in place so I could get a measurement. Rather than use the bracket I had I decided to use a circular type bracket with extended arms to hold the arms. I then made a sketch and proceeded to machine what I had drawn.


----------



## gbritnell

I initially made the crankshaft longer on one side to accommodate a governor mechanism of some sort. With the bracket machined I installed the arms and slid the assembly onto the crankshaft. I found out that even by making the crankshaft longer I didn't have enough space to install the necessary links to make everything work properly. Knowing that the gear width from the drawing is wider than it needs to be I fixtured the cam gear and removed .030 from the face of the gear. The crank gear was slid onto a mandrel and locked in place with the set screw and .030 was removed from it also. The flywheel was again slid on the crank to check for spacing and at the point I had enough room the flywheel was still about .04 beyond the end of the crankshaft so I started looking for another way to get more room. 
The cam follower is .140 wide at the circular mounting end and narrowed down to .125 where the pushrod locates. The pushrod is only .094 diameter so if I made a new follower and reduced the base width to .120 and the upper part to .105 I would still have room to spotface with a .094 ball mill, so that was the next step. 
With the follower narrowed I could then take an additional .02 from the cam gear on the cam side. I set the gear back up in my split bushing and removed .020. I then remounted the crank gear and took an equal amount off of it. 
I now needed to make new pivot bolts for both the cam follower and the cam gear. That follower was easy but the cam gear bolt would now need to be redesigned to accept a lock-out arm. 
I turned up a shoulder bushing leaving and extra .125 on the outboard side.  I tightened it into the threaded hole and marked a reference line onto it so that the flats and slot would be properly oriented after machining. 
With the bushing still on the rod I mounted it into my dividing head, milled the flats, cut the slot and drilled for the pivot bolt. 
Another trial assembly and everything looked good.


----------



## gbritnell

Now for the lockout arm. Being as the pushrod floats in the small pocket in the cam follower and really has no way of being attached with a clevis I had to come up with a way of supporting the pushrod while it was being held in the open position. I decided that if I extended the lockout arm and machined it so it would straddle the pushrod it would serve two purposes, one to support the pushrod when it might fall out of the conical pocket and two to lockout the pushrod for the coasting cycles. 
With all the bits and pieces assembled I took some more dimensions and made up another sketch. The rear of the lockout arm would fit into the spool with a round tip, no problem but it took a little figuring to get the other end. 
I put a piece of steel in the mill vise and cut it to the overall dimensions. I then put the pivot hole in. Using a .125 end mill I profiled all of the shape from my sketch. I then mounted a slitting saw and cut the pushrod slot into the end. The lockout arm is .062 thick but .145 thick where the support area is so I milled the top surface in this setup. 
Once the arm was removed from the parent stock it would be virtually impossible to hold so with the slitting saw I cut the part off in two levels, one to give me the .062 width and one for the widened end. The extra stock would have to be removed by hand filing and burring. 
I lightly cleaned up all the surfaces and slid the lockout arm into it's bracket and the crankshaft spool. I moved the governor weights to the outside position, moving the lockout arm into the 'lock' position. I then realized that as the arm angles inward it starts to touch the cam gear so I took it out and filed a clearance angle on the inside surface. Reassemble and recheck. I left extra stock on the arm so that there would only be a tiny boss which would catch a stop on the pushrod. I filed more stock away, checking and rechecking as I went. I finally got the arm to work as intended by moving the governor weights in and out. The support area for the pushrod is always engaged over the rod. I turned up a small bushing and threaded it for a 1-72 set screw. This would be the stop for the lockout arm. 
You can see in the two pictures the lockout arm in both postiions.


----------



## gbritnell

As I mentioned earlier the governor weights and arms were supplied by Gail. Thanks again!


----------



## gbritnell

Here is a better picture of the head and rocker arm assembly. Along with this picture are a couple more of the crankshaft and an overall shot with the other flywheel slid in place. Tomorrow I will start on the carb.
gbritnell


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## Parksy

These engines are just awesome. Do the big ends need some sort of oil cup for longevity or does a drop of oil suffice?


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## 10K Pete

Brian, your 'variations' are very interesting. Would it be possible for you to 
post a couple of pics showing the lockout arm and pivot better??

Thanks,
Pete


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## gbritnell

I have to take the flywheels off tomorrow to drill and tap them so I will take some pictures of each individual part. 
Actually it's George not Brian.
gbritnell


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## 10K Pete

gbritnell said:


> I have to take the flywheels off tomorrow to drill and tap them so I will take some pictures of each individual part.
> Actually it's George not Brian.
> gbritnell



George, I'm sorry. I've read so many posts today......

Pete


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## gbritnell

Hi Pete,
Here's the closeups I promised. 
They include the lockout lever, the governor weight and arm, the governor arm bracket and the spool. 
gbritnell


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## gbritnell

I have all the pieces finished. Just waiting for some 1/16 dia. brass tubing for the fuel line. I finished the carb, muffler, Hall bracket and magnet disc. 
I radiused all the corners on the base and fuel tank. I filed and sanded all the machine marks. Funny how you can't see machine marks until you take pictures. 
I have no idea what weight spring will be needed for the governor weights but threw something on them to keep the mechanism for locking out. 
When I made my first engine I deviated from the drawing and made my own spark plug. This one has an 8-36 thread. The insulator is Corian. 
gbritnell


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## GailInNM

Looks great George.
Gail in NM


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## 10K Pete

That's a real beauty, George! And thanks a lot for the detail pics, they help a lot.

I must build a Tiny. Soon!

Pete


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## Parksy

Just lovely. I'm curious about the single pushrod. I understand that the vacuum pulls the intake open and inhales its air and fuel, but is this setup to keep things simple? Why not intake and exhaust pushrods?


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## gbritnell

Hi Parksy,
I really can't answer your question. I have thought about it ever since I got interested in old engines, gas and steam. My best guess is that if two cams and pushrods were used and the governing mechanism was to still lock out the exhaust then the intake would be opening and closing and the piston would be blowing air back through it into the carb. In doing so the moving air would be taking fuel with it and spitting it out of the intake tract. 
In this single actuator setup once the exhaust is open there is no vacuum so the intake never opens. 
On these engines one has to remember that the carbs were very simple and did not have a variable throttle, until later, so they used the governor for basically speed and power control.
Actually quite ingenious when you look at the whole picture. 
gbritnell


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## steve-de24

George, you have made a very nice version of the Tiny, I particularly like your hit-n-miss latch mechanism.  I will be interested to hear how the lapped aluminium piston in a cast iron cylinder works out - I hope you don't run into any problems with different rates of thermal expansion. By the way are the flywheels the standard 1.75 inch diameter? They look to be a bit bigger but that could be me getting confused by the perspective of the pics.
Many thanks for taking the time to post the info and photos.
Regards,
Steve


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## gbritnell

Thanks Steve,
The flywheels are 1.75 diameter. I had the other engine sitting on the bench when I started this one and didn't realize that I had made the first ones 2.00 or a touch under starting with 2.00 stock. I'm not sure how this one will run with the somewhat smaller wheels but as soon as I get the fuel line I will try it out and see. 
gbritnell


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## GailInNM

George,
For what it's worth, the flywheels on my hit and miss "Tiny"'s are 1.75 diameter by .468 thick brass with a 3/16 inch thick rim. The engines are governed at 3000 RPM and run about 6000 RPM with the governor disabled. In the hit or miss mode they hit about one in every 10 revolutions at idle. At idle I cannot tell the difference if I remove one flywheel. I run these engines at the high 3000 RPM as I use them to power gauge one locomotives.

 With one flywheel removed, the only time I can tell the difference is when the engine is loaded I get a few more double hits to bring it back up to speed when both flywheels are installed. I think this is because of the increased inertia of the two flywheels. With either one or two flywheels installed about the lowest reliable governance speed is about 1600 RPM. This is with a 5 to 1 compression ratio.
Gail in NM


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## gbritnell

Thanks Gail,
That gives me an idea of what to shoot for. 
gbritnell


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## Parksy

gbritnell said:


> Hi Parksy,
> I really can't answer your question. I have thought about it ever since I got interested in old engines, gas and steam. My best guess is that if two cams and pushrods were used and the governing mechanism was to still lock out the exhaust then the intake would be opening and closing and the piston would be blowing air back through it into the carb. In doing so the moving air would be taking fuel with it and spitting it out of the intake tract.
> In this single actuator setup once the exhaust is open there is no vacuum so the intake never opens.
> On these engines one has to remember that the carbs were very simple and did not have a variable throttle, until later, so they used the governor for basically speed and power control.
> Actually quite ingenious when you look at the whole picture.
> gbritnell



Thank you George. This makes sense. I will use this style for my next project.

Cheers!


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## gbritnell

Gentlemen,
The Tiny air cooled engine lives! The only problem I had was I first tried running it on straight gas and it stuck the piston a couple of times. The piston was lapped to the cylinder so it probably only had a couple of tenths clearance. I then mixed up some synthetic 2 cycle oil in about a 40:1 ratio and it solved the problem.
I can run the complete tank of fuel through it with no overheating and no sticking. 
https://youtu.be/mbiM_qRLj8M


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## kuhncw

Nicely done, George.  The engine sounds good and it is certainly a busy little guy.

Chuck


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## steve-de24

Congratulations George on a nice running engine. Can I ask about the crankshaft ball bearings. Are they retained only by the pressure from the bearing caps or is there some other way to stop them moving along the crankshaft that I cannot make out from your photos?  
Regards, Steve


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## gbritnell

Hi Steve,
The caps were bored in place to about .0005 smaller than the diameter of the bearings. With the caps tight it holds them in place. 
gbritnell


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## steve-de24

Hi George,
Thanks for your quick reply.
Regards Steve.


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## Scott_M

Well, I am a bit late to the party. But want to join the club. I built a Tiny too!  







I started a new thread here     Another “Tiny” I.C.  My first model engine

Scott


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## stevehuckss396

Very late, but very nice!


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## Scott_M

Thanks Steve!

Scott


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## gbritnell

It's been awhile but I believe I posted the drawings to make it a true hit and miss engine. If you want to go that direction send me a PM and I will give them to you if you can’t find them. Being as we're just a stones throw away (Strongsville) you're welcome to come and look at my engines


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## GailInNM

Welcome to the "Tiny" club. Great workman ship and a nice runner. I will be following your new thread to see what variations and innovations you have incorperated in your "Tiny". 
Gail


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## Scott_M

Thanks George and Gail
I have already incorporated some of your ideas into mine. I really appreciate the willingness of this community to "share" it is very refreshing, especially in this day and age.
George, thanks for the offer ! I would like to meet you  Kind of busy this week, I will send a PM later this week. I think my heat problem would be greatly diminished if it wasn't running 6-7 grand. Hit & Miss would solve that.

Thanks guys  

Scott


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