Harvard/Stickney Jr Model

[JPar]

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

 

[Engineville]

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

 

[JPar]

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.

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

 

[idahoan]

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

 

[JPar]

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

 

[idahoan]

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

 

[JPar]

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

 

[idahoan]

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

Dave

 

[JPar]

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

 

[idahoan]

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

Dave

 

[JPar]

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

 

[JPar]

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

 

[awake]

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.

 

[JPar]

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

 

[awake]

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!

 

[johnmcc69]

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

 

[awake]

Just a thought...

... and a good one. Thanks!

 

[teeleevs]

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

View attachment 114436

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.

 

[teeleevs]

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

 

[JPar]

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