Originally Posted by
bjr48
I know of a couple of different ways to tell if the piston/sleeve is very worn. How do you determine if it's "mostly" worn and should be pinched to avoid running it until the very end?
i have been told a couple ways......one way is to hold the engine up by the crank and the compression should hold up the engine for 10 seconds......also i was told to look in the exaust port and watch the piston, turn the crank over and it should feel spongy or start to make compression before the top of the wrist pin gets to the top of the exaust port.......the first one i read on the net, the second one was told to me by Ed Bridges himself. Ed also said the 10 second rule is a pretty good way of getting an idea for your engine wear.......
on a side not that same race day i spoke with him about pinching a engine, he laughed and said "i got a pair of vice grips over here i can pinch it for you" and laughed like it really dont work well.....im shure there are ppl. who will dispute that but that is just one opinion from somebody who knows a lot more than i do when it comes to nitro engines.