# Harvard/Stickney Jr Model



## JPar (Mar 15, 2020)

Hello.  I've acquired a Harvard (also called Stickney Jr.) model that was built from a casting kit from BP Machine.  I think these kits were sold about 20 years ago, but are no longer available.  

This model is mostly complete, but has some issues.  For starters, the cylinder was not drilled/tapped for an oiler or for a spark plug (N.B., it is fitted with a mechanical ignitor for spark).  Also, the timing gear on the eccentric shaft is not keyed, as called for in the plans.  So I've decided to completely disassemble the engine and go through it piece by piece, checking out everything before I re-assemble it.  Luckily, I received a set of drawings with the engine, along with several pages of notes.

I'm sure I'll have many questions as I do, and so I'm wondering if anyone here has built, or currently owns one of these models.

Thanks,
   John


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## Engineville (Mar 15, 2020)

John:
    I currently own one of these models which I bought some 18 years ago at the Florida Flywheelers Swap Meet.  Additionally, some 10 years ago I actually saw one of these engines running at an engine show at Lafayette, Indiana.  This gentleman spoke of spending several years learning how to make it run.  If you care to, I can correspond with you about this model engine off-line.  I would much enjoy such a conversation.
Marion
Engineville


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## JPar (Mar 16, 2020)

Engineville said:


> John:
> Additionally, some 10 years ago I actually saw one of these engines running at an engine show at Lafayette, Indiana.


I saw one of these running at the Portland Indiana show in August 1997.  It was shown by the owner of BP Machine, the company that sold the castings.   I've also seen at least one of them running in a video.  So it is possible to get them to run.



Engineville said:


> John:
> If you care to, I can correspond with you about this model engine off-line.  I would much enjoy such a conversation.
> Marion


Thank you!  I'll send you a PM to get the conversation started.
John


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## idahoan (Mar 16, 2020)

My buddy built one a few year back from a set of castings that I had and he talked me out of.
It runs real nice on the ignitor.

Dave


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## JPar (Mar 16, 2020)

Dave, that's a really nice looking model.  Is the coil (the one under the tank) functional, or just for show?
John


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## idahoan (Mar 17, 2020)

Hi John 

The coil is functional, I think this is the second one that he made. The first one was smaller but got too hot if I remember correctly. 

Dave


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## JPar (Mar 19, 2020)

Pretty well reduced to bits now.  I was really happy that the main valve body (i.e. head) and cylinder sleeve were relatively easy to remove.  This will make it much easier to add holes for a spark plug and cylinder lubricator.  The connecting rod has an offset of approximately 0.100", which I guess was done to compensate for a mis-alignment of the cylinder bore and crank throw.  I'm still working out exactly why this was needed.  On the drawing, the connecting rod is perfectly straight with no offset.
John


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## idahoan (Mar 20, 2020)

Spark Plug? Why not use the ignitor that is part of the engine?

Dave


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## JPar (Mar 20, 2020)

idahoan said:


> Spark Plug? Why not use the ignitor that is part of the engine?



The spark plug port is called for on the drawing, so I thought I might as well put it in while the engine is apart.  If the ignitor proves troublesome, I'll still be able to run the engine and have fun taking it to shows.  If the ignitor works without issues, I can always put a plug in the hole.  Or, I could fit a non-functional model of the hot tube set up like the original engine had.  The spark plug port is located in just the right place for it.
John


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## idahoan (Mar 20, 2020)

I see, yes I had forgot that it goes where the hot tube would have been.

Dave


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## JPar (Mar 23, 2020)

Does anyone have a close-up of the top of the engine, like the picture below?  I think there should be something to hold the valve cage down, and would like to confirm this.  Whatever it is, is missing on my engine.
John


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## JPar (Apr 8, 2020)

The plans call for two 10-32 set screws in the flywheel hub.  The flywheel has not been drilled and tapped for these, so I need to do it.  The plans show the set screws orthogonal to the crankshaft, but the only way I can envision doing this with the equipment I have is to tilt the flywheel 20 degrees from vertical as shown in the attached picture.  Will the screws still have adequate holding power at that angle?  Or, is there another way to drill & tap these holes that I should consider?  I have a Rockwell vertical/horizontal combo mill, and a Buffalo 15 drill press.  The flywheel is 8" in diameter and approximately 1" wide.  The rim is about 0.040" wider than the hub.

Edit:  The flywheel is keyed to the shaft, so the set screws are there just to retain the flywheel's axial position.

Any & all help and advice is appreciated.
John


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## awake (Apr 9, 2020)

John, I am mostly a newbie - only one completed engine to my credit. I made mine with a keyed flywheel secured with set screws, just as you describe - and like you, the only way to put in the screws was at an angle.

Observations from my one-engine experience:

1) It is difficult to get into the space at the minimum angle without interfering with the quill or some other part. And unless your setup is much more secure than the slap-dash affair I came up with, it is quite easy to break a tap in the process. NOT that I would know this from personal experience. Ahem.

2) For some reason, I wound up with a fine-thread set screw on one side, and a coarse (standard) thread on the other. I don't know how in the world I managed to do that. But it does provide practical experience in the difference in how they perform in this application. Even with some medium-strength thread locker, the standard-thread set screw comes loose pretty much every time I run the engine. The fine-thread screw came loose without thread-locker, but with the medium-strength (blue) it has stayed secure.

3) A possible issue that may affect the performance of the set screws in this application is that when I machined the key way in the flywheel, it came out just a bit loose. I have wondered if the screws might hold better if the fit were very tight, so that the flywheel had no ability to wiggle back and forth.

4) I don't know the extent to which, if any, the set screws being at an angle contributes to any of the above. I have read here and there some hints that set screws on keys are subject to this sort of issue on a flywheel - just so much pulsation and vibration.

Take all of the above with the appropriate grain of salt, given my limited experience - but hope it will be of some use.


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## JPar (Apr 9, 2020)

awake said:


> 4) I don't know the extent to which, if any, the set screws being at an angle contributes to any of the above. I have read here and there some hints that set screws on keys are subject to this sort of issue on a flywheel - just so much pulsation and vibration.



Awake, thank you very much for your reply.  It is most helpful.  Just to be clear, do your set screws bear directly on the key?  On my engine, the drawing shows the set screws positioned 180 degrees opposite to the key.  I wonder how much difference, if any, that makes?  I suspect that they'll leave burrs that could make the flywheel difficult to remove.
BTW, I'm a newbie too - probably obvious from the questions I've been asking. 
John


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## awake (Apr 9, 2020)

John, my set screws do bear directly on the key. I have always understood this to be the "right" way to do a set-screw-and-key combination - with the screw at 180° from the key, I'd be afraid the key could work its way out sideways, especially in the rambunctious context of a small engine like this. But again, I'm no expert!


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## johnmcc69 (Apr 9, 2020)

An old trick with set screws & shafts was to drop a small piece of lead shot into the hole before installing the screw. The screw will mash the lead to the shaft & not damage or raise burrs on the shaft.
 Just a thought...

 John


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## awake (Apr 9, 2020)

johnmcc69 said:


> Just a thought...



... and a good one. Thanks!


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## teeleevs (Apr 10, 2020)

JPar said:


> Hello.  I've acquired a Harvard (also called Stickney Jr.) model that was built from a casting kit from BP Machine.  I think these kits were sold about 20 years ago, but are no longer available.
> 
> This model is mostly complete, but has some issues.  For starters, the cylinder was not drilled/tapped for an oiler or for a spark plug (N.B., it is fitted with a mechanical ignitor for spark).  Also, the timing gear on the eccentric shaft is not keyed, as called for in the plans.  So I've decided to completely disassemble the engine and go through it piece by piece, checking out everything before I re-assemble it.  Luckily, I received a set of drawings with the engine, along with several pages of notes.
> 
> ...


I run my open crank railway trolley engine on 2 stroke fuel and the oiler is only a dummy, sorry have no pictures of it on this device.  The original engine is 2 cylinder Fairbanks Morse of 1880s design, the model has 34mm pistons, all the patterns and castings we did ourselves, it is powerful enough to give me a great ride on 7 and quarter inch track.


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## teeleevs (Apr 10, 2020)

Photos of rail trolley taken recently Feb in NSW Australia before the Pandemic became serious.


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## JPar (Apr 20, 2020)

Slow going, but making some progress. I made a new connecting rod and wrist pin, drilled/tapped a hole in the cylinder for an oiler and made an elbow for the oiler.  Also stripped the paint and cleaned up the parting lines on the castings.  Drilled/tapped the flywheel for set screws (positioned so they bear on the key), and added shims under one of the main bearings to eliminate binding.
Here it is, getting some run-in time on the lathe.  Next steps are to lap the main & exhaust valves, and fit a key to the eccentric shaft gear.
John


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## Stefan-K (May 14, 2020)

JPar said:


> The plans call for two 10-32 set screws in the flywheel hub.
> 
> Edit:  The flywheel is keyed to the shaft, so the set screws are there just to retain the flywheel's axial position.
> 
> ...



Hey Jon
Just a hint. Set srews a not a good idea.
Please keep in mind, that when you use the setscrews as the plan calls for, they will press a mark in your crankshaft when you fasten them that makes it almost impossible to remove the flywheel from the crankshaft. This is my own personal experience.
BTW Nice build!


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## JPar (May 14, 2020)

Stefan-K said:


> Hey Jon
> Just a hint. Set srews a not a good idea.
> Please keep in mind, that when you use the setscrews as the plan calls for, they will press a mark in your crankshaft when you fasten them that makes it almost impossible to remove the flywheel from the crankshaft. This is my own personal experience.
> BTW Nice build!


Thanks for the response.  I decided to position the set screws so they bear on the key, which I'm hoping will avoid that problem.
Now that spring is here, I've been busy with other things and progress on the Stickney has been slow.  I did lap the valves as mentioned in an earlier post.  I put the cylinder, piston, and head together to check the compression.  The rings are a little stiff, but the compression seems pretty good.  I think it will be good enough to run.
Now I have to figure out how to broach a keyway in the timing gear.  The shaft is only 5/16" diameter and I don't have a collar that small.
John


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## awake (May 15, 2020)

John, you've definitely made the right choice in putting the set screws over the key rather than over the shaft.

That said, my own limited (one model) experience has been that this approach has an aggravating tendency to loosen, especially on the flywheel. I also had a problem with the ignition cam coming loose; it too is also secured with key + set screw. I put blue thread locker on the set screws, and that seems to have fixed the ignition cam, and definitely improved the situation for the flywheel ... but still the flywheel set screws loosen over time. Interestingly, the gear on the crank shaft, also secured with key + set screw, has never given a bit of trouble.

I have wondered if part of the problem might be that I wound up with the fit on the key in the flywheel just a little loose - it is perfect on the shaft, but just a bit big in the flywheel. Particularly with the mass of the flywheel, this allows it to "wiggle" a bit under the uneven forces at work on it, which in turn works the screws loose ... again, this is just a theory at this point. Hopefully, YMMV!

On edit - I was looking back through the thread, and realized that I had already posted most of what is above. I apologize for the repetition. I am sure it is not age at work. I am sure it is not age at work. I am sure it is not age at ... wait, did I already say that??


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## almega (May 16, 2020)

I don't know how deep the threaded hole is for the set screw, but if deep enough you could put a short set screw in and tighten to the key and then add a second set screw on top of the first and it should stay in place. You could also see if you can find a nylock set screw which would not be as likely to loosen. I know they are available in 10-32 from Fastenal.


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## Stefan-K (May 17, 2020)

My solution for this is, I´m milling a small flat spot on the crankshaft where the set screw left its mark. The screw can sit really thight on this flat and you will have no problem to remove the flywheel if necessary.


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## awake (May 17, 2020)

Stefan-K said:


> My solution for this is, I´m milling a small flat spot on the crankshaft where the set screw left its mark. The screw can sit really thight on this flat and you will have no problem to remove the flywheel if necessary.



Interesting - I've not tried this with an engine, but in various shop tools, this approach has seemed to be more susceptible to having the screw loosen. Of course, that may just mean that I am using inferior shop tools ...


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## Cogsy (May 17, 2020)

awake said:


> Interesting - I've not tried this with an engine, but in various shop tools, this approach has seemed to be more susceptible to having the screw loosen. Of course, that may just mean that I am using inferior shop tools ...



I think, but don't know for sure, that if you machine a flat for the set screw then you have to get the screw exactly perpendicular to the flat when you tighten it. If it's on even a slight angle, the shaft can rotate a touch and this releases the tension on the screw and it invariably comes loose.


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## awake (May 17, 2020)

Oh, yes, that is definitely true. But I've had a couple of tools that, even with every effort to get it "just right," sooner or later come loose. Maybe the flats aren't cut right, or more likely, the screws are a bit off-center. On one of the problem tools I finally re-machined the shaft and pulley to take a key ... need to do that with the other one.


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## JPar (May 19, 2020)

almega said:


> I don't know how deep the threaded hole is for the set screw, but if deep enough you could put a short set screw in and tighten to the key and then add a second set screw on top of the first and it should stay in place. You could also see if you can find a nylock set screw which would not be as likely to loosen. I know they are available in 10-32 from Fastenal.


I like the idea of a second screw, but unfortunately the hole is not deep enough.  When I eventually get the engine running, I plan to keep an eye on things and if the screws have a tendency to loosen I'll try Locktite or the nylock screw you mentioned.
John


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## almega (May 20, 2020)

How shallow is the setscrew hole? Nylock setscrews in 10-32 are available as short as 1/8" long, so two of those would only require a hole 1/4" deep. Your idea of Locktite would work as well if you use the right kind.


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## Chiptosser (May 20, 2020)

Gentlemen!  
Is there a reason, why you can not make a tapered key for the flywheel?


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## Brian Rupnow (May 20, 2020)

Industry standard is to have one set screw over the keyway and one at 90 degrees to it. Experience has shown me to use a large enough diameter hub that the set screw has a minimum of 3/16" of material to pass thru, and to never use a set screw smaller than #8.


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## awake (May 21, 2020)

Chiptosser said:


> Gentlemen!
> Is there a reason, why you can not make a tapered key for the flywheel?



In my case, I haven't yet figured out how to machine the tapered key slot with my shaper.


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## ALEX1952 (May 22, 2020)

Tapered shafts and bores commonly have wood-ruff keys and are generally retained by a nut, a tapered key would serve no usefull purpose as one end would be very deep in the shaft depending on taper, a parallel key does the same job, again you have to find a way of keeping the assembly together as they will try to part.


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## JPar (May 22, 2020)

ALEX1952 said:


> Tapered shafts and bores commonly have wood-ruff keys and are generally retained by a nut, a tapered key would serve no usefull purpose as one end would be very deep in the shaft depending on taper, a parallel key does the same job, again you have to find a way of keeping the assembly together as they will try to part.


The flywheel bore & crankshaft on the Harvard/Stickney Jr. model are straight.
John


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## ALEX1952 (May 22, 2020)

Sorry this was in respnse to the chiptosser question which on second reading I think I got the wrong end of the stick, he is meaning to taper the key and drive it home, which I have never been a big fan of as they can fret and become loose then they get a whack with a any blunt instrument till its eventually kn*****ed won't tighten any more and the keyway is probably damaged.


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## Chiptosser (May 23, 2020)

This the the method use for over a hundred years an flywheels and pulleys on shafts.
If the taper is not right, there can be problems with loosening or cracking. 
That is why there is taper per-inch information, to properly size the key.
Woodruff  wasn't that common or easy to do way back.  Time and labor was cheap compared to tooling.


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## JPar (Aug 17, 2020)

For the past few months, work on the little Stickney has taken a backset to other projects.  I'm trying to get back to it now, before I forget how it all goes together  .

The plans call for a key as well as a set screw in the cam shaft gear.  The builder drilled and tapped the gear for a set screw, but did not broach the keyway.  I've acquired the specified broach (1/8") and collar (5/16")  and am ready to do the job.  I'm wondering if there are any "tricks" to ensure that the keyway is centered on the set screw hole?  Or is it just a case of "line it up by eye the best you can"?  (My brother used to say "A good eye is better than a bad measurement!")

Thanks,
John


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## Cogsy (Aug 17, 2020)

Lots of people advocate for 2 set screws, one over the key and one at 90 degrees to the key. So you could call the one you have the 90 degree one and place the other over the keyway once you've broached it.

Otherwise, maybe have the screw in the hole with the wrench on it and indicate the wrench handle? It depends how sloppy a fit the screw is but it should get you close.


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## Chiptosser (Aug 18, 2020)

You have to be careful about putting the setscrew over top of the key.
Make sure that the hub is thick enough, where both the key and setscrew will be.  If you fit up a tappered step key, it will be as the original was made.
They didn't use set screws in the old engine flywheels.


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## JPar (Aug 18, 2020)

Chiptosser said:


> You have to be careful about putting the setscrew over top of the key.
> Make sure that the hub is thick enough, where both the key and setscrew will be.


That's a good point.  I took a closer look at the hub, and after subtracting half the thickness of the key, I'm not sure there's enough "meat" left for the screw.  The drawing actually shows the key and set screw placed 180 degrees apart, but I don't like that because the burr left by the set screw can make if difficult to remove the gear.
For this application (camshaft), I wonder if it would be sufficient to omit the key, and just mill a flat on the shaft for the screw to bear on.  I wouldn't think a camshaft gear would be subject to the same loads as a flywheel on a crankshaft.  Thoughts?
John


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## Barnbikes (Aug 18, 2020)

Keep the key and mill a flat 180 degrees for the set screw.


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## JPar (Aug 31, 2020)

I got distracted by other things, but finally got back to the cam gear.  I broached the gear and cut a keyway in the shaft, 180 degrees opposite the set screw as suggested.  I also milled a flat for the set screw to bear on.  It was my first attempt at cutting a keyway in a shaft.  I'm happy with the way it all came out!
  John


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## JPar (Sep 4, 2021)

I'm finally getting back to the little Stickney after a hiatus of 9 months or so.  It's starting to come back together now.  Last week I assembled the crankshaft, base, eccentric shaft, and flywheel.  Yesterday I assembled the piston, sleeve, cylinder casting, and top casting.


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## Tim1974 (Sep 5, 2021)

Looking good stick at it


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## gbritnell (Sep 5, 2021)

It's coming along great!


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## LorenOtto (Sep 5, 2021)

JPar said:


> I'm finally getting back to the little Stickney after a hiatus of 9 months or so.  It's starting to come back together now.  Last week I assembled the crankshaft, base, eccentric shaft, and flywheel.  Yesterday I assembled the piston, sleeve, cylinder casting, and top casting.
> 
> View attachment 128882


Very glad to see you are back at it - keep the posting coming.


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## JPar (Oct 14, 2021)

The little Stickney is back together and essentially complete, except for some work on the ignitor.  I've set it up for spark plug ignition, so the ignitor work can wait.  I tried to run it and got a few putts.  But then I discovered a serious issue.  The crank throw, which is supposed to be a tight press fit, is slipping on the shaft.   It's really frustrating and depressing to discover this at this stage of the game.
I disassembled the engine.  Here's a photo of the crankshaft, showing the throw and crank pin.  There are probably a couple of ways to fix this.  I'm thinking of drilling and tapping for an axial set screw, which will be half in the shaft and half in the throw.  There's probably a name for a screw like this, but I don't know what it is.  The second photo is a crude drawing, trying to illustrate what I mean.  The drawing also shows a set screw to ensure the crankpin is secure.  I'm thinking that might not be a bad idea, and it's relatively easy to do while everything is apart.  There's very little twisting torque on the pin, but it would be a disaster if it were to work its way out of the hole.







I'm thinking of using #8 screws.  The crankshaft diameter is 0.500.  The pin is a little smaller.

What do ya'll think of this approach?

Thanks,
     John


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## JPar (Oct 15, 2021)

I decided just to go for it, and made the fixes as described in my previous post.  I used 2 #8 screws to secure the throw to the shaft, and 1 #8 to secure the pin to the throw.  It looks pretty good to me.


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## JPar (Nov 3, 2021)

Here are a couple of photos of the little Stickney, reassembled with the repaired crankshaft.  The engine is more or less complete, with the exception of the ignitor which is non-functional at this point.  I've rigged the engine for spark plug ignition, with an electronic buzz coil and hall sensor for timing.
I've run the engine a few times, but never for more than about 30 seconds or so.  It ran fairly well for short periods, but then stopped for reasons that I'm not yet sure of.
During the last run, the head gasket blew out.  Fixing that will not be easy, as the head is actually inside of the cylinder casting.  It will require a complete disassembly of the engine.  I think I'm just going to put it aside for awhile and work on other things.
  John







Here's a short video of it running.




Your browser is not able to display this video.


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## JPar (Nov 3, 2021)

I just realized I should have put something in the pictures for scale.  The engine is about 25 inches tall, including the wood base and the brass fuel tank on top.

John


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## JPar (May 10, 2022)

JPar said:


> During the last run, the head gasket blew out.  Fixing that will not be easy, as the head is actually inside of the cylinder casting.  It will require a complete disassembly of the engine.  I think I'm just going to put it aside for awhile and work on other things.
> John



I put this aside a few months ago, and it's time to try to fix it.  After reading some older posts about gasket material, I think I'm going to try Teflon sheet.  I have a question for those who have used this successfully.  Should I use any type of sealant with the Teflon, or should I just leave it dry?
John


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## Stefan-K (May 11, 2022)

Hey John

If you are using Teflon sheet as gasket material there is no need to use any kind of sealant. Just leave it dry.  Mostly i use Teflon sheet with a thickness of 0,3 to 0,5 mm. That`s enough. But remember Teflon tends to flow away under constant pressure and heat, so a sheet too thin will leak again after some time.
Stefan


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## Mike Ginn (May 11, 2022)

In my experience you should never use plastic sheet of any kind as a gasket.  Basically they all flow and at some point leak and PTFE (Teflon) does just that.  I always use proper fibre (fiber!) based gasket sheet which is readily available in a range of thicknesses and easily cut - ideally using a cnc craft cutter but it works with scissors and or craft knife.
Mike


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## JPar (May 11, 2022)

Mike Ginn said:


> In my experience you should never use plastic sheet of any kind as a gasket.  Basically they all flow and at some point leak and PTFE (Teflon) does just that.  I always use proper fibre (fiber!) based gasket sheet which is readily available in a range of thicknesses and easily cut - ideally using a cnc craft cutter but it works with scissors and or craft knife.
> Mike


Mike, could you kindly provide a little more information.  What sort of fiber/fibre are you speaking of?  A link to a specific product would be helpful.
The gasket currently in the engine (the one that blew out) I made from a standard paper gasket material, commonly available at auto parts stores here in the U.S.  I want to try something different this time.
John


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## Mike Ginn (May 11, 2022)

Hi John
I use a material called  Flexoid (0.25mm thick) which is made in the UK.  It does appear on the US version of eBay and I have provided the link in the attachment.  The sheets I use comes as A4 size which is about the size of your Letter paper.  I am not sure how larger a gasket you need.  You could use annealed copper sheet which is the traditional gasket material.  

If you have difficulty getting this material I could send you a sheet in a letter envelope or a sample.

I can also explain how to cut out the gaskets using a cnc craft cutter - its not straight forward and uses dxf files.

Best of luck

Mike


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## JPar (May 11, 2022)

Mike, thanks for the information and the kind offer to send a sample.  I will keep it in mind as I consider all the options.  Ideally, I'd like something a little thicker, e.g. 0.015 inches (0.4 mm) or so.  The gasket is relatively small - approximately 2 inches (50 mm) in diameter.  I do not have a CNC craft cutter, so no need to explain that.

While looking at Flexoid on eBay, I came across another option I'd never heard of.  Does anyone here have experience with "flexible graphite foil sheet"?  The information I found suggests that it's good for high temperature automotive use, so perhaps it would work OK for models?  It's available here in the US.
John


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## JPar (May 20, 2022)

Got the engine apart, and verified the head gasket is indeed blown.


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## JPar (Jul 19, 2022)

I made a new head gasket from 0.4 mm graphite foil sheet.  The engine is back together, and with a little fiddling is running pretty well now.  I took it to a show this weekend and ran it for at least 2 hours over a three day period.  The new gasket seems to be holding up so far.  Here's a video:





Your browser is not able to display this video.





John


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