Well, I've decided to change horses mid stream, so to speak. First photo shows the bike with the PK-80 engine. I'm sure this engine with the expansion pipe and three speed transmission would have made a nice combination. But for this old bike it just doesn't look right, to my eye, and the sound will also be "off" for a 1934 motor bicycle. Even though the change I'm making will set the completion of the bike farther into the future, in the end I think it will be worth the trouble.
So, the PK-80 with pipe will get listed under swap and shop tomorrow.
The "new" engine is a 1940's British made Villiars 98cc 2 stroke. It is heavy, durable and slow revving. Even with higher displacement, it may not outperform the PK-80. I don't mind if that's the case because to my eye this engine looks right and having heard them on U tube I know it will sound right, too. Especially with the sidecar, I'm not interested in going very fast. I think 30 mph as a cruising speed is the upper limit for this old timer.
So that's what's up. Since these photos were taken this morning I have made a new rear engine mount which allows me to lower the engine more. The engine mounts will be welded to 1" split collars so there will be no welding or alteration of the frame. The collars are going to work very well I think and will allow me to adjust the fit of the engine.
The jackshaft I got from Cannonball2 looks like it will be a problem mounted behind the seat post, so after some long staring this evening Fasteddy and I came up with a different location which is forward of the engine and will attach to the front down tube by means of another set of 1" split collars. At least that's what we're thinking at this stage. I have ordered a second set of collars since two will be needed for the engine mounting and two for the jackshaft. The collars will allow for no drilling or welding of the frame and will also be adjustable. I like these split collars a lot.
I think what we're going to do is use a Max Torque clutch with bearings instead of bronze bushings and a pulley belt drive for the primary drive to the jackshaft. Then chain drive from the jackshaft to the freewheel. My understanding is that this makes for a smoother drive line.
I wanted to use the kick start with this engine, but there is no way to make it work on a bike. This engine was originally used on a lawnmower and the kick start is all wrong for fitting onto a bike. My leg would be running into the kick start, so it is out which leaves just a couple of options for starting. I could use a setup similar to what Harry 76 did with his Villiars Beach Cruiser (one of my favorite builds) which used a lever and idler to engage the belt drive. If I did that then theoretically I could start the engine with the pedal as a kind of kick start. One problem with that is fitting up the lever which requires a good bit of reach and leverage. With no upper cross bar that limits where to anchor the lever. The other option is an automatic clutch which would not allow the pedal start, I believe. About the only way to start it would be with a leather belt wrapped around the flywheel... which is the way I'm going to go. The inconvenience of a belt pull start will be offset by the convenience of the automatic clutch (no need to disengage the belt when coming to a stop). More tomorrow...
SB