Author Topic: Upshur Vertical Single - plans per 1990  (Read 1386 times)

Offline IanM

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Upshur Vertical Single - plans per 1990
« on: July 15, 2021, 11:19:29 AM »
Dear Upshur engine builders,

I am impressed by the various Upshur engines built and described on this forum. I have the plans, bought in the last year from the Upshur family, for the 1990 dated Vertical Single.  My core question is that, given the variety of some design details I see on Upshur engines, are there any sensible changes I should consider. One that I had in mind is whether I should go to plan on cylinder head bolting?  Plan says 4 radial screws tapped into fin upper section. I have seen 2 milled slots in the fin section and then long bolts from head to upper frame plate as an alternative approach I think?

Equally, the design suggests either screw thread cylinder liner into base flange or solder - any views on what works best?
At risk of overloading this posting, I am thinking of building with the O - ring version of the piston versus the piston ring version - comments very welcome.

Regards

Ian

Offline rklopp

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Re: Upshur Vertical Single - plans per 1990
« Reply #1 on: July 15, 2021, 06:02:51 PM »
I think the Upshur Twin, which I built, is similar. I ended up adding long studs to tie the cylinder heads to the frame. In the first iteration, the cylinder heads were tied to the cooling fins with screws, the cooling fins were interference-fit to the cylinders, and the cylinders were tied to the frame with short studs through a flange at the base (not soldered). I found that the cooling fins started to slide off the cylinders because the interference fit could not withstand the temperature swing and combustion forces pushing on the underside of the cylinder head. With the long stud arrangement, the cylinders are compressed between the head and frame, and the cooling fins see no appreciable axial load other than from the head gasket squeeze. In addition, the engines (plural, because I built six) are much easier to assemble, because the nuts on the prior short-stud flange attachment to the frame were hard to access.

Offline IanM

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Re: Upshur Vertical Single - plans per 1990
« Reply #2 on: July 15, 2021, 08:20:01 PM »
Thank you - I'm interested that you did this - and 6 times, congratulations. May I ask if you drilled the fins to take the studs or as I saw in one build, milled slots along the length of the fin pack?

Regards Ian

Offline rklopp

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Re: Upshur Vertical Single - plans per 1990
« Reply #3 on: July 16, 2021, 03:05:43 AM »
Thank you - I'm interested that you did this - and 6 times, congratulations. May I ask if you drilled the fins to take the studs or as I saw in one build, milled slots along the length of the fin pack?

Regards Ian
I drilled (actually milled) down through the fins. I had to mill, because the holes were half in the fins and half in solid metal. It was quite the challenge and required using sqeally noodle long 1/8” endmills in incrementally longer lengths.

Offline IanM

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Re: Upshur Vertical Single - plans per 1990
« Reply #4 on: July 16, 2021, 07:11:51 AM »
Thank you. Extremely useful. Forewarned is.. etc etc.

Regards

Ian

Offline Art K

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Re: Upshur Vertical Single - plans per 1990
« Reply #5 on: July 16, 2021, 01:02:33 PM »
Ian,
I cant take much time right now but I have built a modified Upshur single. If you page through the rebuild
https://www.modelenginemaker.com/index.php/topic,9589.0.html
You can see some of the changes I made. I used a 3 piece case and ball bearings on cam & crank. If you have any questions get in touch.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline IanM

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Re: Upshur Vertical Single - plans per 1990
« Reply #6 on: July 17, 2021, 10:11:40 AM »
Art

That's a very interesting link, thank you. I shall have a look in detail. I liked the crank machining. It looks like this engine has quite a few variations to its original form.

Regards

Ian

Offline Art K

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Re: Upshur Vertical Single - plans per 1990
« Reply #7 on: July 17, 2021, 11:42:37 PM »
Ian,
Yes it has a lot of modifications from stock, but I used the prints for all the major areas. I worked on it last year had trouble with the mill, sold my parents home and and am just to the point of getting back to work on it.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

 

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