Homemade 4-Stroke Single

I know John was trying to keep the power down on purpose and the atmospheric intake did its part. Since the VW barrel and piston was about 300-400cc at its stock stroke, he cut the connecting rod in half and joined it with the Honda 125 two-stroke roller bearing crank after cutting that connecting rod as well. He joined the two rods together with the resulting diplacement at around 250cc. The carb is tiny as it came off a 50cc two stroke engine. He figures it's going to produce about 2.5 horspower. I've included a somewhat blurry picture of the other, non-modified, half of a VW head. The other half is what he trimmed off lots of fins and such.
I watched him experiment with using just one ring versus two rings on the piston, since one didn't produce enough compression for him. He also switched out the atmospheric intake valve spring with a lighter one so it might idle better. Just amazing!

If he could make us engines to replace the outgoing HT's, that would be truly amazing! You don't see many people like this though. Most of the guys who work on engines that I have encountered replace them rather than build them themselves.

How much power does he think it could make without being limited?
 
Well that would be truly amazing! John loves everything vintage and when push comes to shove, he chooses to do it the old fashioned way. It was always my idea that someone should remanufacture something like those old turn of the century 4-strokes. I had spoken with John about it a long time ago and when he started to build that engine that's the direction he took. I don't think that this would work in this modern, environmental impact time. I do wonder what we'd need to do to make one be able to pass the EPA tests yet still retain that look and function. The little modern 4-strokes look essentially like little briggs & strattons (ugly) to me. But ****, it's just that those modern motors were design for things like weed whacking and such that they ended up looking like that. Someone just need to rework their little crankcases a bit to make them round and then lengthen the stroke so they'd be better suited for a bicycle application. At least John's motor is a step in the right direction.

I don't know that he would go to try and get the "most" power out of that setup since then it wouldn't be suitable for a bicycle. He only went with that setup for two reasons. One, it's about the size/configuration of most of those old motors and two, he could get the cylinder, piston and head from the VW and the crank from a Honda 125 motocross bike easily (as in free) or he already had them.
 
Threads like this one are just amazing - most up;ifting thing I've seen for a few weeks.
 
Well John beat me to it. I have been saving parts for a while now. I was looking for a barrel for the 36hp VW it is 3" and a perfect fit for some of the B&S engines I have parts saved for. I built a small Hit & Miss engine a few years ago and ended up making my own intake spring. If the valve is heavy it will have a hard time at speed. You can turn it down on the lathe. Good job and that is going to look beautiful hanging in a period frame. I am going to follow this one close. Have fun, Dave
 
Dave, I don't think we can't have enough of projects like these so good luck with yours and keep us informed. John must have had the same koolaid as you. When he showed me the intake valve off his motor as he was changing to a lighter spring I couldn't help but take note of his modifications. He had taken the stock VW intake valve and hollowed it out to within about a half an inch from the head. Then he had carefully dished out the valve face to remove as much weight as possible. I'd love to see your progress on the motor you're collecting parts for and if you have pics of your hit an miss.
 
This has got the juices flowing. I am going to get the parts in order and start getting this thing up on the bench. I have a few cranks, cam's and others. I like the head, and I have a VW head. I just got a lathe and mill. I have the plans for an engine out of the Boy's book from the twenty's saved. I have boxes of B&S parts from a shop that shut down, been thing about this for a long time. Have fun, Dave

The pic is of the Hit & Miss I built. Honda 125 crank and barrel
 

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