alecsammy

I have a set of dart cylinder heads 308 big block iron eagle heads milled to a 110cc chamber. The engine is a gen 6 502 with flat top pistons with a relief cut on the intake side nothing on the exhaust side .020 recesssed in the hole standard rod length .039 head gasket , 1.7 ratio rocker arms . Does any one out there have a similiar set-up and what cam are you running max lift intake and exhaust. The valve in my heads are 2.25 and 1.88. Just want to see the biggest cam that I can run without any clearance issues and what should I expect for valve clearance . There should be some type of formula that can be used to figure this out. I know the cam set-up make big difference do install to the cam specs. Thanks Alec

BenPerfected

Lot's of variables to assume you have an adequate clearance. Checking specifically with a head gasket and some clay is the safe method. I have 105 CC Dart 308's with custom flat top pistons w/ deep valve reliefs (max according to CP). We also have a net .735 intake lift. Someone should be able to give you the exact procedure to check the piston to valve clearance with your exact parts.

ezstriper

those heads are cut a bunch and changing the cam is going to be a crap shoot of sorts..gonna need to ck piston to valve clearance to ba sure...Rob

Jeff P31

Using the clay is the safest way to know for sure . A pain in the azz but a lot cheaper than doing it all twice . Just my .02 Jeff

BenPerfected

I suspect you have a set up issue with your cam. On a BBC design, it is my understanding that it borders on impossible to have piston to valve clearance issues with the exhaust valve. Our Dart IE 308's were cut approx .100 and there was no need for exhaust valve relief in the pistons, even with a .735 net lift the clearance is significant (first post was incorrect as the intake has net lift of about .715).
Needing an extra washer on the head bolts after milling is typical.