So my 232 has flat-top pistons, no valve reliefs, and the combustion chamber is a simple wedge. I thought it had a flat shelf for squish, but it just tapers down to flush on the side away from the plug. I've never been able to run much ignition advance on this motor. The compression is high (9.5:1) so maybe that's it. Maybe some predetonation from the crud in the head? It wasn't too sharp though. Plugs were the right color, no detonation damage. Though this thing has pinged very lightly under heavy loads in hot weather, there's no sputtery crap anywhere, so I guess I kept it OK. LP and synth oil sure runs clean! 20 years and I just wiped the top of the piston with a clean rag to read ".030" on the piston top. If there's cylinder top ridge it's pretty damn small. No black crud under the valve cover at all, just clean oil. I assume the bottom end is the same. No way I'm touching that. I'll put up with the slight pan leaks. When I put the head back on, I'm gonna take Widdiker's advice and run a bead of JB Weld around the head to block seam! _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list