Pruitt, Regarding squish clearance, I personally have had good results running the squish at .015 to .020" in both 101's and 91's. I run mostly alcohol, and Hartman Blimp pipes or similar. Make sure the screw-shell of your spark plug doesn't protrude into the combustion chamber. Whether you run alco...

Jeff, I have bored several macs on my lathes, with mixed results. The cylinder liner in some I have worked on seemed to be very hard to cut, almost like they had been tempered (work hardened?). Assuming you have mounted the block in your lathe so that the cylinder axis is perpendicular to the cranks...

At all the vintage events I've been to, there have been a variety of karts in different stages of modification, ranging from "period correct" to nearly as extreme as the machine in your photo. Although the machine in your photo isn't to my taste either, I can appreciate the fact that someone spent a...

Dear Rob, Your analysis and comments on the recent vintage kart accident in Pa has elicited a great deal of discussion on the REAR message board. Opinions regarding vintage kart racing and modifications to vintage karts vary widely, which is part of what makes our hobby so fascinating. Because not e...

The factory rod length for 101's and 91's can be found in the technical section of this website, and there is a range. The amount of stretch tolerable prior to failure would vary; when building an engine it is a good idea to measure the rod you are using for initial length; that way you have a basis...

Greetings! 101's are great engines, and even in stock form are pretty potent. If you compare stock '91 rods with stock MC101a or b rods, notice that the only difference is the '101 rods are longer, but not beefier. If you keep the rpm down to no more than 12,000, your '101 will last a long time, but...