Another item for clarification: The reeded .020....

We never attempted the hackery and butchery described above on this engine. I have no idea about different reeds, carb opening dimensions, etc.... Aligning the intake ports side to side yes......but none of the tank/air intake mods.


One other item on hopping up .049/051's.... after we found a cylinder (pre-honing room) and c'case fit that aligned up the side transfer ports like we wanted, we'd take the cylinder into the honing room and start gently honing it to shape. We wanted the last 0.020" of piston travel, right at the top of the piston's travel to be a slightly friction fit. Slight. You could feel it with your fingers, but not enough to really stick it hard. Another way to measure this was the last 15-20 deg of crankcase movement was a slightly friction fit. This yielded the best compression retention post-breakin. It took longer to break in, but once you took the time.....You would have good compression long after the "stock" piston/cylinders went the way of the dodo. Too tight, and you would fail the ball socket on the piston's bottom.

The shape of the cylinder would be cylindrical until the very top of the cylinder. Then it would become conical and narrowing. The reason? heat distortion. When running, the cylinder would become a cylinder with the application of heat distortion, instead of the stock cylinder which would be slightly "Y" shaped under run conditions. The purpose was compression retention.

This type of cylinder never went into production. The average user would lean their engine out at the start and run their buggies, PT-19's and P-40's right out of the box. We HAD to set dimensions so the engines would not seize out of the box, or our warranty returns would skyrocket, and the nasty spirited customer support phone calls became gruesome. Remember, we were at the entry level for 99% of our customers.

Now in reality.....we're talking dimensions of +/- 0.0005". I've not checked, but I don't think parts are readily available anymore to do this type of minutia. But I present it here for historical purposes.


Now for some comedic but historically accurate information. We had one phone call come into the support line, from someone (sounding like an adult) who was slightly inebriated. They asked Kyle if we were a porno service......You see......e answered the phone with: "Cox action hot line, may I help you?" Keyword that got fouled up I'm sure...."action"......


Hoping some of this old information helps.......



Dave