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Upshur Horizontal Farm Engine - Mike's Version

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mikehinz:

--- Quote from: Brian Rupnow on November 17, 2021, 11:09:45 PM ---Nice job Mike. Reminds me a lot of what I went thru when I built the Kerzel hit and miss engine. I have three or four different hit and miss engines, but they are all running viton rings. I think the Viton ring cause considerably more drag than cast iron rings, so my miss cycles were never as long as I wanted them to be.----Brian

--- End quote ---

Brian, I'd certainly like to get a little longer coast period between hits.  I did check how much drag I have and it seems very low to me.  I checked it by removing the spark plug and then spinning the engine by hand and it coasts for quite a long time.  But you could be correct that rings would drag even less.  When I made the piston, I cut the o-ring groove to apply only about .005" squeeze on the bore ID vs the high squeeze typically recommended by the manufacturer's bulletins.  But I don't have enough builds under my belt to make any good guesses on how to improve it.

The other thing I wonder about is the hit-n-miss mechanism design.  Most Uphsurs that I've seen videos on seem to run about like mine, with the exception of Rudyduby's engines.  On other hand, most Farm Boy engines seems to run well and coast a really long time between hits.  Perhaps there are subtle differences in the mechanism??? But that's just a guess.

Anyway, I did manage to build the engine and does hit and miss so I'm happy about that!  I'll certainly try to build yet another engine and see if i can manage to do better.

Thanks for taking a look and commenting!

Mike

Roger B:
One of the keys to a long coast period is a powerful hit. It may help to adjust the carb and timing with a load on the engine to get the best results and then see how it runs off load.

mikehinz:
All, thanks very much for watching this build of my version of Upshur's Horizontal Farm Engine.  I really appreciate the feedback and comments!

I'm officially wrapping this build up and am already on to the next one.

I'm in the process of posting some final pix of the engine in the Showcase area of the forum at this URL:

https://www.modelenginemaker.com/index.php/topic,10675.msg245558.html#msg245558

I put it on a nice wooden base with a name plate. I'll add just a few comments to the showcase thread and that will be that! 

Thanks again!

Mike

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