Time for a new Horizontal Hit and Miss engine

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Brian Rupnow

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I have completed the Farm Boy style governor on my hit and miss engine, and it does everything that I had hoped it would do. I'm getting a good differentiation between hit and miss cycles, the governor is operating and the engine is running good. When I first built this engine, I used a different governor, similar to that used on the old Hercules hit and miss engines, but I didn't have any way of adjusting it, and due to lack of room it was a failure. I'm very pleased with the way this has worked out.---Brian
 

Brian Rupnow

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Well Sir!! That new oiler is a pretty thing. So far I have been running the engine on 2-cycle gas, which has some oil mixed with it. Makes a Hell of a mess all over everything. That oil doesn't really burn---it lubricates the piston and then spews out the exhaust and covers everything on the engine. I'm hoping that the new oiler will serve to lubricate the piston but not to the point where it is spewing out my exhaust. Now that the engine is running, I will switch back to the home made carburetor. The purchased carburetor was only a temporary thing, to ensure that I wasn't going to have carburetor problems which are rather horrible to diagnose.
XpRISe.jpg
 

Nerd1000

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You might try using TC-W3 oil for outboard motors, it burns at lower temperatures than regular 2 cycle oil.

It's also worth noting that regular 2 cycle premix is set up for the engine running full power, at light load and idle there is far more oil than needed.
 

Jasonb

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You are better off using the drip feed oiler than adding much if any to the fuel as it is a hit and miss engine the drip feed will still keep lubricating when the engine is freewheeling, mixed oil will only get drawn in on the hit cycles.

Most engines of this layout also have a hole in the top side of the piston above the wrist pin so some oil can drop down and lubricate that which oil in the fuel won't do either.

You can still put the 2-stroke oil into the drip feed so any that does get up past the ring will burn off.
 

Brian Rupnow

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Wife is out Christmas shopping. I am down in the shop playing. I've been changing governor springs this morning. I had a weak spring on the governor arms, and the engine would idle very, very slowly. Only thing is, at that slow an rpm, the engine only has to burp once and it stalls. Then I tried a stronger spring, but the engine revved to high, even though the hit and miss was working. Then I put my original weak spring back in, but cut two coils from it. That seems to have done the trick. My idle speed is a bit faster than it was, but it's fast enough that if the engine does "burp" the momentum of the flywheels carry it on thru the cycle to the next firing stroke. That purchased oiler works really well---no mess all over my engine from unburned oil. I've got a grandson coming over this afternoon to watch the original Avatar movie with me, then next week we'll go and see the second Avatar movie at the theatre.
 
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Brian Rupnow

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Okay, I'm happy with the engine now, and next week I will put the home made carburetor back on it. I feel confident now that if someone builds this engine from my plans, they will end up with a working hit and miss engine. I have revised and updated the drawings, and will be sending a new drawing package to anyone who has purchased the plan set. If you are really bold and are looking for a project in the new year, I sell the complete plan set for $25 Canadian funds. This gives assembly drawings, sub assembly drawings, parts lists and detail drawings. If you want to buy a plan set, contact me thru the forum.---Brian rupnow
 

Brian Rupnow

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Don't know Sparky. I'll check it tomorrow. I may design something that lets me alter the spring tension without having to change springs.--Brian
 
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Brian Rupnow

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I am being asked about the tension and compression springs used on this engine. Here is a run down of the 4 springs which are used. The intake valve spring is a compression spring 0.013" diameter wire x 0.75" free length x 0.215" outside diameter. The exhaust valve spring is a compression spring 0.025" wire x 0.75" free length. x 0.300" outside diameter, The pushrod return spring is a tension spring 0.022" wire diameter x 0.190" outside diameter with a loop at both ends x 1 1/4" center to center of loops. The spring between the ends of the governor is a tension spring 0.019" wire x 0.213" outside diameter with a loop at both ends, the center to center of loops is 0.9" free length.
 

Brian Rupnow

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This video shows my hit and miss engine running with the home made carburetor on it. My first few runs with this engine were made with a purchased Traxxas carburetor on it until I got everything tweaked and adjusted properly. Then I removed the Traxxas carburetor and installed the home built carburetor, which actually works better than the Traxxas for this application. Plans for this home made carburetor are included in the drawing package.---Brian
 

mnay

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Brian,
Just something to try.
The late Bob Shores suggested Coleman Fuel with 10% WD-40 mixed in. Burns very clean and also keeps the cylinder lubricated.
I have run my Hit and Miss on it and have not had to use any other lubrication.
 

Brian Rupnow

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Mnay--Thanks---With the drip oiler on the engine I don't have to mix any oil with the fuel now. Just straight Coleman fuel.
 

Brian Rupnow

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So, my friends, this is the end. It has been a good build, mostly everything only got machined once, and it hits and misses like it is supposed to. I'm ready for Christmas, and there's a bottle of Baileys upstairs with my name on it. Merry Christmas to you all, and may we all have a great New Year.----Brian
 
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Brian, thanks again for your time to share your knowledge and skills with us, that truly is a fine-looking machine and runs as good as it looks, you have a way of not making it difficult when it really is, again thanks for sharing with us, after you get the Holidays behind you makes one wonder what is next. Joe
 

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Thanks again for a nice project and a nice series of posts following its build. As always, I enjoy the saga of each one and your posting of your experiences "warts and all."

Merry Christmas and Happy New Year and enjoy that Bailey's.

--ShopShoe
 

karlw144

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Brian, I sure enjoy your designs and builds. Amazed at how quickly you go from “I’m bored“ to having a running engine. Schmuck ups and redirects are just the way it goes sometimes. Was in Barrie once about 20 years ago and traded an Amco shaper for a tuba (long story here). Spent 3-4 weeks every winter in Kapuskasing doing tests for GM. Don’t miss that at all😂😂.
karl
 

Brian Rupnow

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Karlw---I worked in Kapuskasing about 50 years ago at Spruce Falls paper company. They had an opening there for a young engineer, as an older guy was retiring. One thing for damn sure, you didn't leave your brass monkey outside at night in the wintertime!!!---Brian
 

Brian Rupnow

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Just a foot-note. When I first assembled this engine, it had amazing compression, and would "bounce back" if you spun the flywheels by hand. I have about 3 hours total run time on it, and each time it ran, it seemed to have a little less compression. Finally, yesterday, it didn't even have any "bounce back" when you flipped the flywheels by hand. It would still start and run just fine, but that lack of compression bothered me. I've never had an exhaust valve or a intake valve burn on me, so that only left one thing, the Viton compression ring. This morning I dismantled things and removed the ring. When set side by side with a brand new Viton ring, the old ring was visibly smaller in cross section than the new ring. I put a new Viton ring in, reassembled everything, and my compression is back in a huge way. The engine starts right up and runs good. I haven't seen this happen before on any of my other engines. All I can conclude is that the first ring gave up most of it's life bringing the inside of the cylinder to a very fine finish. I don't expect this to happen again, but thought that I would mention it here.
 

Gordon

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Just a foot-note. When I first assembled this engine, it had amazing compression, and would "bounce back" if you spun the flywheels by hand. I have about 3 hours total run time on it, and each time it ran, it seemed to have a little less compression. Finally, yesterday, it didn't even have any "bounce back" when you flipped the flywheels by hand. It would still start and run just fine, but that lack of compression bothered me. I've never had an exhaust valve or a intake valve burn on me, so that only left one thing, the Viton compression ring. This morning I dismantled things and removed the ring. When set side by side with a brand new Viton ring, the old ring was visibly smaller in cross section than the new ring. I put a new Viton ring in, reassembled everything, and my compression is back in a huge way. The engine starts right up and runs good. I haven't seen this happen before on any of my other engines. All I can conclude is that the first ring gave up most of it's life bringing the inside of the cylinder to a very fine finish. I don't expect this to happen again, but thought that I would mention it here.
Is it perhaps due to the fact that you were adding oil to the gas and when you put on the drip oiler you no longer added oil to the gas? Has this happened since you stopped using oil in the gas?
 

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