3.4camaro

iTrader: (1)

I understand the concept of PTV clearance. The piston chases the exhaust valve closed and the intake valve chases the piston open. Is there a certain magic formula to determine if you will have an issue? Or is the only reliable way to measure it involve modeling clay?

I'm asking because I want to go as big as i can without flycutting, it seems like a big pain.

Please someone shed some light on this for me. Thanks!

brad8266

iTrader: (23)

Just flycut, it isnt that difficult.

To check PTVC you have to clay or use the dial indicator method. There is no magic formula for PTVC.

Xtnct00WS6

iTrader: (8)

It's best to decide on the heads you want (how much power can you afford) and then ask around to see how far people have gone in regards to cam duration, gasket thickness, valve size and milling. The tolerances you can get away with, will change drastically depending on the head too. An ETP head with a non stock valve angle will have better PTVC than a LS6 head. Like Brad said, there's no formula for this. You can get a good idea if you'll have problems by asking around about a specific setup.

quick346

iTrader: (4)

I think it should be a sticky. what heads /what cam /gasket thickness and how much ptvc you had.

I think that would be a great thread to have around .

pman

iTrader: (6)

i feel the same way, i am in the same boat. i dont feel like fly cutting and i can make a custom cam at work to whatever specs i want. i have stock heads we are porting and going to put a little bigger valves in.