So my Bro blows his 7.3 PSD (took a big gulp of LIQUID propane), and I helped him with the valve job while it was down, and I noticed some specs in the factory manual. While the top ring end gap seemed normal, the new spec for 2nd. ring end gap is .07...... What's with that? CTDs like this? Also curious about the Keystone style rings.
Please skip the silly flames. It ain't a CTD, but other than the rediculous PMR rods (he replaced them), I thought the engine was pretty cool, and besides, he can kick my butt!

 

43 views , but no replys! Comon guys, I know there have to be a bunch of you that build these engines..............I'm beggin over here! I really want to learn the reason for this. And while I'm on my knees (no snide remarks), how about the deep groove cut into the piston between the two compression rings?

 

Well I can tell you the groove between the rings is to stop ring flutter, been doing that on race cars for years. The ring gap is mostly sized by bore size and fuel being used or cyl pressure.