David Kerzel Hit-Miss Engine (Roger L version)

Ray:
The third photo shows the cross drill hole called the orifice. The air is traveling thru the carburetor into the engine. Should the hole be pointing towards the engine or away from the engine. Currently I have the hole pointing away from the engine.

Thanks
Roger L
 
Yes you have it right.
I only made one carb that is similar to the one you made and that hole went all the way straight through from inlet to outlet.

Ray
 
I built the base and the gas tank. The base needs a coat of stain and some finish. The fuel tank is made from a brass pipe fitting and I soldered the filler neck and the outlet tube to the tank body. The ends are pressed in with some locktite. I have the quad ring for the piston so I will cut the groove in the piston tomorrow. The ignition components are on order and should be here in a week or so. I am about as far as I can go until the ignition components show up.

IMG_7550.JPGIMG_7552.JPGIMG_7553.JPG

Thanks
Roger L
 
The USPS really sucks lately. My ignition system has been sitting in the Cleveland, Ohio anex since January 9th. I get daily updates saying the package is moving to the final destination but it just continues to stay in Cleveland. Maybe one of these days it will show up. I am heading out of town for a week long work trip on Saturday. Hopefully it will arrive before I get home.

Roger L
 
Well I am back working on the engine. It took forever to get the ignition components. I ordered the components from a place in Florida between Christmas and New Years. They were shipped USPS. They sat in Cleveland for over a week. When they finally arrived the Hall Effect sensor was missing. That arrived about a week later.
Tonight I mounted the magnet and the Hall Effect sensor. I need to finish hooking up the ignition components and then I will give it a try. Hopefully I will get it to run this weekend.

IMG_0130.JPG

Hope for the best.
Roger L
 
I worked with the motor over the weekend and could not get it to run. I touched up the valves and put a shim under the quad ring on the piston to get more compression. Tonight I was able to get the motor to make some pops. It would run for a few seconds then stop. That is very encouraging. Now I think the problem is the intake valve or the carburetor. I sent Ray an E-Mail asking for some words of wisdom. I am real close to getting the motor running.

Roger L
 
Update on my progress.
I was out of town for business last week so the first time I had to work on the motor was today. I changed the carburetor to one from a RC airplane engine and found a very light spring for the intake valve. I also made a sleeve to go over the shaft of the intake valve to limit the stroke to about 1/16 inch. I am using a string wrapped around the flywheel to turn the motor over to save my wrist.
I was able to get the motor to run for about 15 seconds a few times. Lots of 5 second runs. It seems like it is running very rich but when I close down the needle valve of the carburetor the motor will not run. I am getting very close. I think the problem is fuel related. Any words of wisdom would be greatly appreciated.

Roger
 
IT RUNS !!!!
Tonight I was able to get the motor running. It turns out the major problem was the quad ring that I was trying to use for the piston ring. I tried to be fancy and use a quad or X ring for the piston ring thinking the two sealing surfaces would be better. Well I was wrong. I dug thru my junk box tonight and found a standard .093 cross section O ring. I put it on the piston and put it back together and you could feel it had more compression. After a few pulls it started and stayed running.
I would like to thank Ray for all of the information, help, and encouragement. Without Ray I would have never tried this project and I probably would not have made it run.
I took some video but the files are too big to upload. I will try to get a smaller video.

Roger L
 
Roger you are very welcome and I did enjoy our conversations and e-mails but the real person behind your success is you. You persevered and now you have gained valuable new knowledge and skills for your next build.
Model gas engine building is very addictive and I see another in your future soon.

Ray
 
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