Pressurized coolant system

[WGTalon]

I have a problem....went to the local track and ran my new combo and noticed that the car was heating up on the way home after some 24-25psi runs. The car never got to the dangerous stage of overheating, although it was not running at its normal operating temperature. I popped the hood and noticed the upper radiator hose was very hard to squeeze, plus once the car had cooled down it had obviously used some coolant. Since this problem I went back to the track and ran multiple 11.9's passes with 20-22 psi with no coolant problems...on the last pass of the day I turned it up to 24-25 psi and the cooling problem returned. I replaced the cap...t-stat and did a compression check and all was fine all 4 cyl's were at 160 ,and its a 1g. Im thinking simply the headgasket/head is lifting at 24psi+ . Just wanted to get some feedback and see if anyone had similar problems. I have already ordered ARP's and a new stock HG. Thanks......

[NosLaser]

I had a very similar problem on my car. The problem itself doesn't seem too technical or advanced, however the potential solutions sure are. My car would lift the head, pressurize the coolant, and explode the radiator. Neat trick huh? I had ARP's torqued 5 ft/lbs higher than factory, and a 4 layer metal head gasket. Head still lifted off. I can attribute one mistake on my part, and that was the fact that I didn't have my block decked with the metal gasket. With my new setup, I will be running a decked and o-ringed block with a Felpro gasket. I'll make sure I keep everyone posted on my progress. Now, potential solutions get a bit more technical. The main reason our cylinder heads lift is the soft aluminum material they are made out of. They tend to flex under power, releasing compression into the coolant passages pressurizing the system, and in turn (in my case) blowing up the radiator. Cryogenics was thought to be a way to go, but after researching it, and talking to people, they say it doesn't really change the property of the metal any to make it any stronger. The theory is it changes the property of the aluminum on a molecular level to harden the material thus giving you less flex. Another idea is to drill the block out to accept larger head studs, such as half inch studs/bolts. The problem here is the valve spring retainer already has a relief cut into it to use the factory-size head bolt, so any larger and you'd have to further remove material and that can get risque. Another idea I have pondered is drilling and tapping for additional studs, however haven't been able to come up with an exact method of execution. The *ideal* way to fix this problem is for some company to cast a badass aftermarket head made from a different material than aluminum. Problem is, it would have to be EXPENSIVE, and prolly not very marketable to your average DSM'er who complains about their Walbro fuel pump whining over their Brittney Spears CD.

[BatmanGSX]

Originally posted by NosLaser
and prolly not very marketable to your average DSM'er who complains about their Walbro fuel pump whining over their Brittney Spears CD.

I know... freaking loud ass Walbro, everytime I try to listen to Britney the damn thing is whining. Seriously though, DSMers do complain a lot about stupid stuff. What do you want out of a 12 second street car?

But back on topic. How the hell are people running 26-28psi if your head is going to lift at 24? What size turbos do you guys have? Cause here's the thing, I could see 28psi on a 16G and not lifting the head but why would you try that when a 16G is useless at boost that high? Are people just retarded? Now I assume you guys are in the 20G+ range where the volume and pressure could lift the head at 24psi. But what about that first guy with the MUTT who ran 28psi and an 11.77? The MUTT is supposed to be a "big" turbo. His block was not o-ringed or anything. What was going on with that?

Luckily I don't have the ballz to run boost that high so I won't have to worry about this much, just curious.

[DSM Storm]

Its cause you guys go easy on the head bolts/studs, tighten those studs to 110- ft lbs, i wouldnt even bother to buy arp's just to torque the head an extra 5 ft-lbs, you should be ok then.

[NosLaser]

<<Its cause you guys go easy on the head bolts/studs, tighten those studs to 110- ft lbs, i wouldnt even bother to buy arp's just to torque the head an extra 5 ft-lbs, you should be ok then.>>

Yeah, that's a surefire way to warp our soft aluminum cylinder heads. If it were that easy, do you think we'd be on here bitching?

[DSM Storm]

I know plenty of guys that do it, have never heard of thier heads warping. *shrug*

[Rdy2race]

and the 7 bolt motor are torque to yeald bolts so it's cheaper in the long rin for a racecar to have studs then the factory bolts.

BM