Coolant blowing out to overflow under boost.

[turbo90gsx]

Just as the title states I am having problems with coolant blowing out of the overflow canister under heavy boost. Right when I put a new Koyo radiator in it started doing it. I have made sure that all of the air pockets in the cooling system are gone and it still does it every time. I run 19psi on an SCM 6152 with a built engine, ported head, studed block, mls head gasket and I think my head is floating up under boost. That is about the only thing that comes to my mind. Does anyone know of something eles that would cause this to happen. Thanks.

 

[firebirdvert305]

Its either 1 of 2 things....like you stated your lifting the head under heavy boost, or the head gasket is shot. Im doing the samething, will hold coolant with no boosting...soon as I throw some boost at it, coolant temps will go through the roof and the overflow will go nuts. Im gonna be throwing on a 4 layer with arp's. When you put that MLS on did you resurface the head?

 

[2gAWDTalon]

You blew the head gasket, period. If you have some way to log coolent temps I bet the car is running hot after also. Check the bottle after boosting, if it has any coolent left in it is it boiling? When you pull the head and replace the HG make sure you have that head decked... especially if you are going to run a MLS. If the car ran hot even a little bit you need to cut the head with a MLS. Consider having your head o-ringed and run a stock style composite head gasket, the will be the end of your problems.

Steve, you should have listened to Jose and got your o-ringed. Maybe you will get it next time... .

 

[turbo90gsx]

Thats what I figured. I had both the head and the block decked about 2 years ago when I built it. The reason I replaced the radiator though is because my stocker cracked in half. I shut the car down right when it happend though. I still think it was enough time being hot to warp the head. I will tear the car down and go through it. I'm sure the head is messed up.

 

[firebirdvert305]

Frank the hell with o-ring for now, the most abuse this head gasket will see is on its best day in its life 40lb/min. The 4 layer will eat that for lunch, granted on a jose's tune. I dont need those "t3" or "pt67" to get me to 125mph, il do that on a 16g 25psi with some spray biotch. BTW hows that tial holding up?

 

[2gAWDTalon]

Turbo, post back and let us now waht you do and how it works for you.
Steavie: This gate sucks, The hallman is all the way up and im at 26psi... I was hoping for at least 30. But, it will get me by.

 

[firebirdvert305]

really? I wonder what spring you had in your tial that you sent off. Im not 100% sure what spring was in that tial dude said ".7 bar" wutever that equals in psi im not sure. Hows the car running otherwise on 26psi? did you goto sunoco yet and fill up? lemme know the details.