Any body have advice on the best low compression piston? I have a cuple in mind but just want some one elses opinion. car has 9.5.1 goal is 8.*.1 in that range. Will I be able to achieve this with just pistons or will I have to go deeper into the rotating assembly.

Also any thoughts on decompression plates. I know they cause a week spot on the motor and affect cam timing, but does anybody have any hard evidence that this is absolutely not the way to go threw personal experiences or knows somebody thats had problems with it. I know a diesel mechanic and he had told me that he has seen these decompression plates standard from the factory on semi's and on other larger commercial turbo diesel applications. Those engines are constantly under load and are working all the time so why couldnt this work on a performance based engines. Not saying this is the route im going just wanted to know some info on it..

 

Not sure how you're NOT going deeper into the rotating assy. while changing these pistons. Do you plan on getting the assembly balanced? I'd recommend that. Generally, a change of compression is done by changing head chamber size, pistons or even head gasket thickness.

I've never heard of decompression plates…but everything you said about them seemed to surround diesel engines. I've not heard of anyone running these on a gas engine, performance or not….but maybe?

I can only assume you're adding a turbo or blower…but there's not enough info in your question to tell…

 

decompression plates are for diesels only. if you want to lower your C/R without tearing into the bottom end use either thick copper headgaskets or change the head with a larger chamber. but why don't you use an intercooler .sounds like your having detonation issues am I correct? If so I would use an intercooler before tearing into to engine unless you wanted to. what are you trying to accomplish

 

I would leave the 9.5:1 ratio. Install an intercooler, run 93 octane, and reduce timing.

 

Whats the application? Blower, turbo? Iron head or aluminum? How big is the cam

 

Turbo dont kno about the cam. Ill find out in a minut.

 

If aluminum head stay 9.5