Time for a new Horizontal Hit and Miss engine

[Brian Rupnow]

You could be right Gordon. That is about the only thing that is different. The oiler does let drips of oil directly into the cylinder, where it is picked up by the piston skirt and spread over the entire inside of the cylinder as a lubricant. If it is the fault of the oiler, then I expect to have it happen again. Really good suggestion.---Brian

 

[JohnBDownunder]

For what its worth Brian, a friend's Farm Boy Hit & Miss needed a new Viton ring after a few, (8hr or so) hour running. He was sure it was mostly the ring polishing the bore during those first hours of running.
It has since clocked up 300 - 400 hours as he runs it for the 4 days of our local agricultural show. I am unsure how many rings have been replaced in total but think a couple as a routine service after each show.

 

[Brian Rupnow]

Thanks John--if it continues a problem, I will make a cast iron piston with heat treated cast iron rings.---Brian

 

[Brian Rupnow]

This is a video of my newest hit and miss engine doing some real work. I'm running low on wood for my kitchen stove and my fireplace, so I hitched up my two field mice Sally and Dobbin and skidded up a few logs from out of the woods. Going to cut them into lengths for the woodstove and get the wife to split them and carry them up to the stove when she gets home from buying groceries.

 

[Brian Rupnow]

Wife said her back was tired from grocery shopping, so I said "Don't worry Honey, I'll do it with my woodsplitter."

 

[Gordon]

This is a video of my newest hit and miss engine doing some real work. I'm running low on wood for my kitchen stove and my fireplace, so I hitched up my two field mice Sally and Dobbin and skidded up a few logs from out of the woods. Going to cut them into lengths for the woodstove and get the wife to split them and carry them up to the stove when she gets home from buying groceries.

Why are you sending your wife out to the grocery store? Why not just go kill a bear for her?

 

[Brian Rupnow]

Bears are all denned up for the winter. Maybe I'll get one when spring comes.----

 

[awake]

They're skinny in the spring, after hibernating; best to bag them in the fall.

 

[Brian Rupnow]

Well, all good things must come to an end. I'm happy with this engine. It hits, it misses, and it keeps running. If you don't know---there are a myriad of things to "tweak" on these engines to make them hit more often---miss more often---switch from hitting and missing to hitting every other stroke while running under load. Counterweight size can be changed. Counterweight spring can be changed. Spark timing can be tweaked. Valve timing may be tweaked. Diameter and weight of flywheels can be tweaked. Carb needle setting can be tweaked. All of these things can be infinitely be tweaked until you get the results you wanted. This engine is finished and it's time to put it up on a shelf with my other fourty engines. Hope you all enjoyed it, it's been fun from my end.----Brian

 

[CFLBob]

Well, all good things must come to an end. I'm happy with this engine. It hits, it misses, and it keeps running. If you don't know---there are a myriad of things to "tweak" on these engines to make them hit more often---miss more often---switch from hitting and missing to hitting every other stroke while running under load. Counterweight size can be changed. Counterweight spring can be changed. Spark timing can be tweaked. Valve timing may be tweaked. Diameter and weight of flywheels can be tweaked. Carb needle setting can be tweaked. All of these things can be infinitely be tweaked until you get the results you wanted. This engine is finished and it's time to put it up on a shelf with my other fourty engines. Hope you all enjoyed it, it's been fun from my end.----Brian

It has been interesting to watch. What's next? Do you have another design, another kind, or another thread going I haven't bumbled and stumbled across?

 

[Brian Rupnow]

No Bob---Nothing new. I am not very happy about the way things were left on the V-twin engine. It ran, but not in a controlled fashion. It is not enough for me that an engine runs. It has to run and respond to the throttle in a controlled manner. I will be jumping back to that thread in the coming week, to see why it ran but not in the fashion that suits me.---Brian

 

[JohnBDownunder]

Thanks again for posting Brian. Your posts are always an interesting read that I look forward to.
John B

 

[Oldiron]

Did you ever post a build of that wood splitter. Looks cool. Bob

 

[Brian Rupnow]

https://www.homemodelenginemachinist.com/threads/model-woodsplitter.24070/

 

[Brian Rupnow]

https://www.homemodelenginemachinist.com/threads/model-woodsplitter.24070/

 

[Brian Rupnow]

I LIED!!! I wanted to see what effect heavier flywheels would have, but didn't want to make new flywheels. I got digging around in that $100 worth of material I bought a few weeks ago from a guy who was leaving the hobby, and found a big piece of 1/8" brass plate. So---I made a "bolt on" piece which bolts to the outside of each flywheel. The danger of making a flywheel too heavy, is that the engine has to fire two or three times before the flywheels can gain enough speed to make the governors work. The danger of making them too light is basically that you won't have a good long "coast" time between firings.

 

[JohnBDownunder]

Yeah, Well now we all want to see it running OR not. Pretty Please.
Well at least I do, probably shouldn't speak for all who are following.
My uneducated guess = a few firing strokes and prolonged miss cycle?
John B

 

[Brian Rupnow]

And now you know how I spent my morning, and a good part of my afternoon. The brass rings added to the flywheels definitely make the engine a bit prettier, but I don't really see a big difference in the hit and miss action.

 

[JohnBDownunder]

Oh Well, looks good. My only suggestion would be that perhaps swapping to countersunk bolts in the brass rings would improve the look?
I really like it,
congrats,
John B

 

[Brian Rupnow]

I'm jumping around a bit with posts about this engine. In a different thread, I deepened the o-ring groove to 0.070" for a 1/16" (actually measures 0.070") cross section viton ring. My original ring groove depth was 0.058", and after watching an engine built by Andrew Whale of the U.K. run the same piston and ring combination using an 0.080" deep ring groove I had to experiment a bit. I had hoped that with a deeper ring groove there would be less friction between piston ring and cylinder, thus giving me longer "miss" cycles. It didn't!! The engine is running very good, but it's running a bit too fast and not getting many "miss" cycles. I now have two choices----either put a weaker spring on the governor arms or add some weight to the counterweight itself. I don't have any weaker springs, but a close examination shows me that I do have room between the existing hexagonal governor weights and the spring itself to add a couple of 0.100" thick brass washers. This will add to the weight of the governor balls, and make the engine go into "miss" mode at a lower rpm.