Zip ties arrived today so I have started the engine mock-up. From the tip of the spark plug to the carburetor located at the bottom of the engine there is a pretty good reach from end to end, leaving few options for engine placement. Here's the first of what I see as possibly two. The other I'll try tomorrow with the spark plug facing the front of the gas tank and front tube of the frame. The second option looks more cramped yet, but the measurement says it is the same distance. I can buy a bit of space with a shorter spark plug which I have, but is not in the engine. The other end with the carburetor, which by the way is a Walbro reed valve and can be in any position in order to run OK... has a bit of wiggle room. In one picture I am holding a tuna fish can against the carb as that looks like my best option, to make a "leaping Tuna" air filter. More on that later, but it is an air filter I have made before and works fine.
I think the engine might look better facing the other way, but will know better when I mock it up that way and then do some staring at it. One way or the other may end up being dictated by the jack shaft assembly which I envision being attached to the seat post.
The engine shaft sticks out a good ways so the overall engine width will be fairly big, a far cry from the Whizzer engine designed for a bicycle frame. Obviously this engine is not. In that way it presents some of the same problems as the Predator and Greyhound motors. Wide. The key way on the engine shaft is close to the end of the shaft so I am figuring on reversing the centrifugal clutch so that the chain sprocket is inboard. I don't see why that won't work OK. The plan then is for the drive chain to come off of the clutch and go to the jack shaft sprocket. Next to the sprocket on the inboard side will be a pulley aligned with the sheave. I could be wrong, but the initial impression I have is that I will not have to alter the frame for belt clearance. I hope that proves to be true.
I can see that I will need to have a wide pedal crank assembly in order to clear the engine... not so much for pedals running into the engine since it is fairly high up in the frame, but for leg and foot comfort in reaching the pedals which need to be outboard of the engine. On my American fFlyer build I have an extra wide one piece crank and will have to see if that will work. Pedal extensions will also buy a little room and if need be I can cold bend the pedal arms. Last choice due to expense would be to buy a three piece pedal crank in their widest configuration from sick bike parts. That would also necessitate buying a bottom bracket adapter. Every purchase adds up.
The Briggs conduit clips arrived today so over the next couple of days I'll grind down the little leg on each one to make it work for affixing the sheave to the wheel. I had originally intended to use a 20" bicycle rim as a poor man's sheave, but I can see that the Whizzer sheave is the real deal. Spend the money where it counts. Thanks again to Chainmaker for that sheave! I'll take a close up photo soon so that you can see how they have made a groove specifically for the V belt so it has no chance of wandering about. Alignment will be precise.
That's it for now.
SB
