I have a built Y8, but I have alot of valve clatter at 2500RPM +, on top of several broken bolt holes both in the cam cradle and in the head itself. My question is what do you guys think of a Z6 head vs another Y8 head... I have heard it both ways, but I was just looking for thoughts...

 

What are your goals? They both have pros and cons.

 

well as of right now, she is all motor, but eventually, I am going to boost it... Been having head trouble ever since putting the motor back together. The overall goal... somewhere around 300hp... hadn't really thought about numbers... just building a solid street car.

 

nothing wrong with either, y8 seems to burn a little faster requiring slightly less timing under boost, im a big fan of the z6 motor, pretty stout for a little pos, plus u get a better oiling system

 

Since you'd like a 300whp car, I assume (or at least hope) that you're going to be turbocharging the engine. The z6 is best suited for this application.

 

definately going boost, I just want to be sure that the rest of the motor is stout first...

 

stock y8 compression -- 9.61:1 y8 block w/ z6 head -- 9.21:1 if you gunna boost it 9.2:1 is a little more friendly but its a small diff.

 

when the block was built, we upped the compressionby decking the block and head as well as using flat top CP pistons (.30 over)... The compression right now is just above 10:1