Stock Head Gasket Pressure

[Mr.Tao]

I know I've seen this somewhere before, but forgot. How much boost pressure can the stock head gasket take before leaking? Or any pressure for that matter?

 

[Jeff_Jeske]

Well a properly running 4G63 with no knock and stock parts is said to hold fine all the way up to 25PSI. Some say at 25PSI the stock head bolts will stretch causing a head gasket leak. Some people replace the stock head bolts with ARP bolts and run much higher than 25PSI. The stock head gasket is VERY GOOD and will probably hold for 600HP as long as you are tuned.

Keep in mind if you have outrageous knock and dentonation the stock HG can blow at any time.

JJ

 

[NOSLO2PT0]

Plenty of guys have run 30psi with stock head gasket and stock head bolts. It's the detonation that kills the gaskets. Also lifts the head with stock bolts.