Head/Gasket problem

[VG30DE]

Same identical problem, 2 different cars...

Drive it easy to moderate, no problems at all. Hammer it and it blows antifreeze right out the radiator cap, overflows the bottle, and makes a huge mess. Fill it back up, all better. Drive all day long. No misfire, no coolant in the oil, no smoke out the exhaust, perfect compression within 5 psi. Both are new rebuilds with less than 2k miles on em. Pull the timing waaay out to 0* base, no power obviuosly, but also no more antifreeze problem. Motor#1 has already been torn down, replaced head gaskets again, looked totally fine anyway, rebuilt, and same exact problem still exists. Both running 160* T-stat with stock water pump and good aluminum radiators.

Motor#1
95, stock shortblock w/110k on it, GT40 heads heavily ported, B cam, cobra intake, 1.7rr's
Problem came after changing heads from stock ones.

Motor#2
86, forged TRW's, balanced, honed, ringed, GT40 heads heavily ported, stock cam, GT40 intake, 1.7 RR's
Problem started from the first time driven.

WTF is going on with these motors??

 

[EMW150]

Which gaskets are you using and what are you torquing them too? ARP bolts?

 

[VG30DE]

Stock replacement GT Fel-Pro motor #1, ARP bolts to 65 ft-lbs

Heavy Duty Fel-Pro's motor#2, ARP bolts first to 65, then tried 75, then tried 85, still doin it..

 

[EMW150]

Check the dowels to make sure they allow the head to sit all the way down. I've had it happen in the past where the dowels were too long for aftermarket heads and were taking the torque load of the bolts instead of the gasket. Also don't overtorque the intake. That is a common mistake. I torque mine to 14 ft-lbs. Overtorquing the intake will try to push the heads outward and also lift and can give you a problem. You may also want to try studs. Just don't exceed 75 ft-lbs. 70 ft lbs on the short / 75 lbs on the long. Stick with the Felpro stock type. 8548-PT-2 or 93333-PT-1

 

[VG30DE]

Anyone else run into this exact problem and fond out why... I have 2 of em doing it so it cant be impossible or never seen before....

 

[VG30DE]

Ayone??