Why does the head gasket blow?

[Razor]

If the gasket doesnt blow, then you'll blow a hole through the piston. The wrong pressure has to go somewhere.

Do you have direct scan Uffe? You may want to get better monitoring equipment and start relooking at everything. EGT's, IAT's, etc.. assuming there is no external issue with vacuum lines, MAF, sealing, etc..

It is common to oring the heads, becuase its easier. but I dont believe in that. If the head is lifting, then thats one issue..if the motor detonates or has bad/improper machining..thats another.

The pump has steel rollers inside it. Thats why the need for lubricant. dunno bout the low turnon..thats another issue..

Cars way faster than yours using stock head gaskets with tremendous success.

HTH

Julio

 

[TheSwede]

Uffe>> In the catalogs i got with the car, POSTON Enterprises has Copper gaskets for stock heads and for stage 2.

Just look on page 82.

is there no detonations after you let the pedal up?

i´m just thinking loud =)
But your car maybe gets to much fuel when you letting go of the pedal, i don't know what it's called, so i take it in swedish, fetspika, thats when there is too much fuel in the cylinders, then it can be an uncontrolled explosion in the cylinders or cylinder which causes the gasket to explode. i don't know, just thinking loud =)

check that the surface of the block and head is straight, or perhaps it's the strange torque sequence, perhaps the headbolts not straighten enough?

tar det på svenska igen, topplocksbultarna kanske inte är sträckta som de ska, för det låter ju som sträckbultar eftersom det ska dras 3 gånger, testa att dra dom 3 gånger nu när du ändå har motorn lös, eller skulle den varmköras emellan?

And for those who thought WTF, the headbolts might not be "stretched" or prolonged as they should be, why else should the torque sequence be repeated two times more?

That's what i can think of...... hope it's any use.

 

[The Swede]

Huh????

TheSwede and The Swede..... OK!

Welcome here Christer!

Thanks for the tip in the Poston catalog!
I found it on page 82, sad thing is that Poston don't have an email adress..... ok, i'll guess i have to call them up later.

Actually i don't know how much fuel and "fetspika" i have after i let the throttle off.

The tourqe sequense is without running the engine hot.

Julio: No direct scan, only turbolink and Casper knock gauge.

And, i forgot to tell you that i found a loose connection when i had the engine out from the car.
It's the one that is located just after the airfilter, maybe this also had something to do how the car act?

 

[Razor]

Uffe,
I think you have a tuning issue more than anything else. It may be the chip your using. May not.

At 100 MPH in the 1/8 mile..you are making some serious power. To which you need better monitoring. Things happen really fast at higher power levels. Not that you cant use T-link and a knock guage at that speed..but only if all issues have been resolved.

Also you havent mentioned using an EGT meter. Maybe your cooking the motor at 1800+ degrees. You cannot trust the factory O2 to be precise. Your TTA was no where as fast as this car..and could tollerate being out of tune better.

I hope you get smarter before breaking more parts. Again..doesnt take much..simple stuff like a PCV, EGR line, MAF meter, etc..can cuase you to POP

If the assembly is done correctly..your only left with electronics. But a sensor is only as good as the information it recieves.

18 year old car.. start with the drivabilty stuff and monitor BLM's.. they will typically show an issue..if there is one. Do some searching under BLM's and get a better handle.

Since air leaks will show up on the computer.

Hope this helps.

 

[S2V6RACER]

I would be more concerned about the heads rather than the gasket. Just my opinion. I don't think your problem lies in the gasket itself.