not sure what section to put this in but here goes. yesterday i went and got my car dyno tuned after heads and cam went in. it did great on motor pulls and even did great on a 100 shot. it was still running fat so we jetted up to 150, we hit it and still did great no knock and still running rich. after words we noticed coolant had came out of the relief cap for the resivior. we firgured it was overfilled but on the drive home it started to overheat so we pulled over and noticed it was extremely low on coolant. so we filled it up and it was fine. today i jetted it back down to 100 and did a couple of motor runs and it was fine but as soon as i hit the spray same thing happened. what gives? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

 

Might be lifting a cylinder head and pressurizing the cooling system, you have Cometic head gaskets?

 

im not sure what kind of gaskets the shop used but i know they used arp bolts. what kind of gaskets do you recomend and will it fix the problem?

 

TTT

 

Sounds like the Heads are lifting on the spray.Find out from the shop what gaskets they used and the torque they did for the bolts.

 

Keep retorquing the head bolts. Since those bolts are reusable, you need to check them a few times if they were torqued with the ARB bolt lube when installed. They can back out a little.

 

Honestly I'd post this in the nitrous section because I think one of the moderators, Al has had this happen... Car runs fine but when you spray it lifts the heads. He is running Cometic head gaskets which don't completely blow like stock GM gaskets.

I suppose you could try tightening the head bolts but I'd find out what the maximum tq is before I do that (don't want to snap one off in the head).

 

i ended up blowing a head gasket and i think it was a GM gasket. i am stepping up to ARP studs but which gaskets do you recomend and where can i get them?

 

ttt

 

Cometic

 

I got my Cometic gaskets from Thunder Racing. Give them a call.

 

what rpm are you turning on the n2o?

 

This has happened to myself and Cammin Beast. What has happened is your head is bent from the juice. Should be about 4 to 5 thousands to get them straight. Your car should run okay on motor but if you redyno your car I can honestly say you will be down any where from 20-40 at the wheels. I have seen this many times before and it always happends on 150 kicks with Cometic gaskets. The middle section of your gasket has also been junked so you will need to replace them too. At any rate you can still run and drive your car but check the coolant leval every few days because weather you know it or not you are going to loose some every day until you go back in and fix this. I am not guessing about this I have seen it many times. GOOD LUCK!!!