| Re: 91 RS Spark Knock, Ping, Detonation, Pre Ignition
| An update just in case anyone followed this thread. I have the engine tore down and found quite a few problems. First off, the side with high compression had a rebuilt head. I'm thinking this is why it had more compression. May be it was warped and it has been shaved to make it true again. I'm not sure. And the valves wiggle quite a bit when pulled a little ways out indicating pretty bad guides. Next thing was the piston ring gaps were lined up. I'm sure that doesn't help compression. And the rings are wore pretty bad. .032 gaps | | | | 
