i built my new motor using a 81.5mm bore with a stock bore headgasket, cp's eagles and a blockguard, it was tunned from the previous setup at 7psi on the afc hack, when i went to the dyno to tune with crome, when we hit 12psi the coolant overflow tank shot coolant out and there was no pressure in the system at all, so i went to buy a new cap and still no luck. I took my thermostat out, and for the first time today it started to over heat a little in traffic, so i'm gonna change the head gasket with a .20 bore and see what happens, by the way, when i hit it first gear today nothin but white smoke out the exhaust. Guys why do u think the head gasket just gave out like that? Could it be headlifting?

 

You probably killed it running the hack with its advanced timing curve. I'm sure its probably been leaking a tiny bit for a while and you just didn't notice it.

 

ttt

 

ouch sound like HG problem