If anyone could help me out it would be great…
Specs:
I have a boosted GSR with JE pistons Eagle rods a block guard
ARP head studs torque16 ftlb and Cosmetic Head Gasket
The car is running on 15-16 psi under hondata engine management, 347 whp

The problem is under boost pressure the stock radiator builds up pressure enough so that the overflow can overflows with fluid only under boost. Immediately the head gasket was suspected to be the problem but its fine no coolant in the oil, the car never over heats. The thermostat was removed, and I replaced the radiator cap with a new one, however pressure still build up to the point where it is overflowing the radiator catch can.

Any suggestions or help would be greatly appreciated…

Thanx

 

still sounds like headgasket.

 

could it be the head isn't torqued down right..?? i just dont c the head gasket being the problem or the car would over heat.

 

hey bro i had the same problem this past summer when i made 350whp. the problem turned out to be the headgasket not sealing correctly. i also had the same symtoms...no coolent in the oil, no oil in the coolent, compression was fine, etc. the coolent would only overflow when i boosted. i got tired of filling up the coolent so i bought a new headgasket, checked the old headgasket for leakage and found it was cylinder 3 and 4 leaking, changed copper o-rings, and so far so good no overflowing anymore.

 

I've seen that same problem when the head gasket was put on upside down on some motors, so I would say head gasket too.

And Sherman, if you don't mind me asking, what were your internals used and head set up when you made 350 whp in an LS? Just curious because I am going for around those same numbers, did it take turbo cams etc?. Thanks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RaNMaN &raquo;</TD></TR><TR><TD CLASS="quote">
And Sherman, if you don't mind me asking, what were your internals used and head set up when you made 350 whp in an LS? Just curious because I am going for around those same numbers, did it take turbo cams etc?. Thanks.
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head setup was a DIY port n polish job, rocket valve springs. block was dart sleeves, JE 9:1 pistons 81mm, eagle rods, oem bearings, arp bolts.

the things that made the most difference were the pnp and my skunk2 intake manifold.

 

Yo Sherman thanx for ur help...

You described my prob perfectly, the same exact shyt. Can i reset the head gasket or should i opt for a new one..? I did a compression test on it and every thing showd fine, so the only thing im thinkin is the head gasket is slowly leaking but only under high boost. If you no of any install steps or anything to make sure it sets properly before i reset the head back on the block would be helpful.? What ftlbs of torque did u torque the head im using arp bolts and its LS/Vtec

Thanx for your help...

 

Head Gasket.........

 

its the head gasket ,thats what happen to my car and , there was no coolant in the oil , and the car was not over heating , the head gasket just gave out , and i had a an exhaust leek in to my radiator which makes it over flow