Recent content by Brian Rupnow

Today I made the nylon points mounting block, the brass ignition points mounting assembly, the ignition cam and opened up a few clearance holes on the main crankcase assembly. It's a beautiful day here in Ontario, bright sun and 70 degrees F. Wife and I went to a take out restaurant and then...

Yowzah!!!--I rooted around in my plate stock and found a sheet of 0.030" brass plate. That will do to make my ignition points arm and the piece that attaches to the ignition rotor. I have enough black nylon left to make the block that holds the other side of the ignition points. I need to make...

One thing for sure, for sure. I'ts a heck of a lot easier to make cams with flat flanks.

Today I will take a crack at making the cams for this engine. These cams do not have a curved flank, so they should be easier to make. I have attached a sketch of the finished cams which will be made from 01 steel and hardened. Lucky for me, I have a piece of 1/2" diameter 01 material on hand.

So, today I made valves. Very small valves. They still have to be cross drilled with a 0.039" hole at the ends for the valve keeper cross dowels.---And I lied!!! Sometime or other I must have made this size of valve before, because in my box of George Britnell wonderful valve seat cutters, I...

I'm getting down to the short strokes on this engine. I still have to make cams, valves, and an ignition point system. The valves are a bit more delicate than those I have built in the past. The valves are 0.094" diameter. All the valves I have made are 0.125" diameter. When will I repair the...

Thank you, Vietti. That is a very novel idea. My engines are only ran at low speed, so I don't anticipate issues with the pushrods. I will keep your suggestion in mind for future engines.---Brian

Yes, that is what the plans call for.---Brian

Today I was busy like the beaver. I made four rocker arms, which are just about at the limit of "littleness" for me to make. Then I made four pushrods, which are posed for the picture, but I haven't actually made the cams yet.

I did cut one thread on my lathe, just to prove that I could. My lathe is not a gear head, so it involved changing a few gears in the back of the lathe. Jason---Why would a fine thread be better?

Good luck!!! My DRO wasn't buggered up, a cable connection had came loose. Big sigh of relief.--I've been thinking about making my own threaded insert to repair the damaged sparkplug threads on one cylinder head. It looks like I can make a piece 3/8" outside diameter with 3/8"-16 thread and a...

Carburetor is finished. A couple of really small parts, well actually 3 machined parts and one rubber o-ring to hold the throttle assembly in place. This is probably one of the simplest carburetors that I have ever seen.

Okay, that's a lot better with the sub base/gas tank mounted under the engine. Now I get to finish making carburetor bits. Something funky is going on with the DRO on my lathe, I hope it's something simple that I can fix.

Since I need a gas tank, as well as a base for this engine, I think this is the way I will go. I happen to have a piece of 2" square aluminum that will provide my material. If I hollow it out from the underside and make a recessed bolt on cover plate with a gasket, it will be my gas tank as well.

We have a carburation system!!! Very simple but ingenious carburetor. I'm happy with this. I still have a couple of carb parts to make, but they are not big jobs. Then, on to the rocker arms.