Overhead Cam Project

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nx06563

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Thought you might want to see my latest design and build project. It is a hybrid of Jerry Howell's V Twin and Brian Rupnow's Overhead cam engines. It seems I've never had an original thought but I'm pretty good at stealing concepts. I do enjoy designing and building engines as long as I don't have to think too hard.
I have the engine fully designed which is to say I have started the build and am correcting problems as I go. I used Autodesk Fusion 360 for the design and had it learn it in the process. Hope this sucker will run when its done!
I designed a single cylinder with the plans to make a V-twin if I get all the bugs worked out of the single cylinder.
If things work well I will make the plans available as long nobody expects a professional job.

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Oh goody, nice neat design with enclosed crank that can be lubricated correctly and doesn't look like a Hardly Dangerous with a leg thrown out of bed.
 
How's it look so far? Anybody see my boo-boo?

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It appears that the intake valve port has a two holes drilled to it? My wife must have been helping....

I did catch the hole drilled at the wrong location before it went thru to the port. Now I have to see if I can use the extra hole or is it time for an new head?
Maybe I can figure out a belt tensioner from the new hole.
 
Getting close. Just have some odds and ends to finish and mount it on some type of base before I give it a spin.

Has good compression and didnt fit any rings yet. I must have gotten the cylinger lapped in pretty well. I'll try it without rings first as see how it goes.

I have started designing the two cylinder and have incorporated some things I learned on this build. Im having as much fun designing as I am building.

By the way, anyone know how to get the pictures to come in right side up?
It seems to turn them even if I have rotated the original before I upload.

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Looks good, I'll be looking out for the running video soon.

By the way, anyone know how to get the pictures to come in right side up?
It seems to turn them even if I have rotated the original before I upload.

If you're using an iPhone or ipad, when you take the picture make sure the 'home' button is on the right, or bottom, of the device and the pics should display right-side-up. They can be problematic to rotate otherwise.
 
Ready to run just as soon as I get the timing belt. I ordered a belt that was out of stock and had to reorder the same belt with a different composition.
As you can tell I don't do much for displaying my engines, I have more fun making chips than sawdust.

I have it setup for a bubble carburator to get it started and will convert it to a real carburator as soon as all the timing is sorted. I am using an electronic ignition with a hall pickup mount for a model airplane engine.

Hopefully I will get it running sometime this week. I have already started the design work for the V-twin version assuming it runs well as a single.

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It runs quite well finally!

I had a few issues to solve first but not too bad.

The flywheel wouldnt compress the tapered bushing and hold tightly on the crankshaft so I had to locktite the bushing to the crankshaft before I seated the flywheel on taper. I evendently made the bushing too big in diameter for it to compress. Have to think on that one for the next version.

I used leftover cams from my build of the Howell V-twin. One wasn't concentric to the center hole so I couldn't keep the valve closed when it was supposed to be without a huge amount of gap on the tappet which really reduced the cam duration. Had a third cam leftover and used it. Don't know why I didn't throw the other one away long ago.

Got it started on a bubble carb but had no throttle control and it tended to run wild so I put a model airplane carb on and after some adjustment I got it running fine. Idles well and throttles up well.

It has the typical one cyl. problem of a lot of vibration but maybe the a v-twin version will be better.

I will post a video as soon as I can get my wife to act as photograher.

I will also make the prints available as soon as I get them cleaned so they are usable.(dont expect much, Im not real detail oriented). I will post them on Allen Howells web forum. He did send a very nice e-mail when I told him I was using a lot of Jerry's design concepts.

I also appreciate Brian Runows input since his OHC engine was the inspiration for this design.

Don't look for a video or prints for a while since I will be RVing for a month.
 
I finally have the design cleaned up enough to make available to anybody that wants it. I make no promises but it should be enough to get it built if you want to.
If you want to see mine run go to your tube and look for OHC Video by Hogan Liechty

Hogan

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Just wanted to say a quick thank you for the video and drawings, it's a great build and i'm sure many people in future will enjoy building it, if it was around when i was looking for my first engine build that would definitely be it. Nice and slow running, Thanks again,
 
By the way, in my spare time I designed a new flywheel to help balance this thing. It was so out of balance it would shake everthing off the workbench when it was running.
It is now better but not perfect.
Balanced Flywheel Drawing v2.pdf
 

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