Originally Posted by
nitrodude
The skirt is there so that at TDC it covers the exhaust port, otherwise the engine looses all the incoming mixture out the pipe. Are you setting the piston at TDC BEFORE you take out the backplate? A lot of engnies have a groove on the backplate because otherwise the skirt would hit it.
Okay, now that you pointed that out, I can see why the extended skirt is there. I got lucky and didn't take enough off the piston to uncover the exhaust port. I just can't figure out why the piston are breaking. All in the same spot. Detonation maybe? Running 30% Byron's with a #4 turbo plug at 7000 feet.
Thanks.