This question is mostly track related where head gasket failure seems to be quite common. Last head gasket failure was caused by a peripheral failure resulting in over-boost condition. What is the prevailing wisdom on head gasket failure and replacing head studs?

Three options:
1. Replace them everytime you replace the head gasket?
2. Change to raceware the first time you replace head gasket (and never have to change again?
3. Never change head studs?

It is my understanding that 951 head studs are one time use. If you change them how do you remove them?

For what its worth, I did search the archives; but did not arrive at a direct answer?

Thanks,

 

You wont get a consensus. Stock, Raceware, and ARP studs are all used with varying success. Stock, Wide Fire Ring, MLS, solid copper head gaskets - w/ or w/o o-ringed head or o-ringed block are all used with varying success.

May want to read through this recent discussion on studs:

https://rennlist.com/forums/showthre...ferrerid=15894

 

I think you will find a wide opinion on your questions. Here's mine FWIW

1. Not unless you have had multiple failures and the studs have been torqued several times;

2. I replaced mine with ARP's and get my block and head back from the machinist today. My project car has had the head off at least 3 times in it's history and I think it's worth the effort.

3. That's really up to you. I feel that repeated torquing of the studs might cause them to lose some ductility especially at higher boost levels.

There's really no one correct answer but once you have replaced them with ARP or Racewear studs you'll never have to consider these questions again.

 

i know that the head stud NUTS need to be replaced, but the studs are not manditory. I know that some people have changed them, but it's a matter of preference and need I guess.

 

Thanks for the inputs -- I found a lot of information on head studs in the recommended thread; but, very little on removing the original studs. Any tips on this?

 

Where did you hear this?

 

If you do chose to remove them I would recommend a machine shop unless you aren't planning on pulling motor. Removing the studs in place can be real dicey since the factory used a very hard thread locker. Most DIY people have had success using localized heat (MAPP gas) to soften the sealant. Even with the best of plans you can easily damage the threads in the block when taking them out. My machine shop baked the block and had no problem at all. There was no trace aluminum on the steel threads and they chased the threads in the block to with a flat bottom tap to make sure all the old sealant was cleaned out. Someone also said not to use a long beam breaker bar to break them loose; they said the preferred method was a T-handled tool that concentrates all the twisting force uniformly rather than the standard offset tool. I'll see if I can find the thread from about 6 months ago with info on removing the studs.

It all comes down to personal choice and if you feel more comfortable with the high-strength style studs or not. I don't think there is any perfect answer.

 

On vehicles that have removable head bolts, they are always recc. to be replaced, some due to bolt stretch others just because. So the opposite is true of the nuts on the Pcars. Since the Nuts are what do the clamping (like the bolts on previously mentioned style heads), they are recc. for replacement.

I know that head jobs are/have been done in the past using the onld ones, I have done it personaly in a pinch, but all my reading b4 doing my head gasket last week, said that the nuts are a recommended part while doing the job. They only cost 1.99 through my suppliers here at my shop, and like 2.39 retail or somthing, so in my opinion it's just good piece of mind to ensure a good clamping force and to eliminate the chance of tightening down a worn nut the last 90 degrees and hvaing it ruin the threads on the stud because it strips.

Just my opinion and 12 years expierience at a shop/machine shop/Grand Am Cup team.

 

I have to thank Alan for posting the question as it is actually my car that had the head gasket failure.

This engine was an unmolested 97,000 motor that ran great but was subjected to 25+ lbs of boost when a vacuum line to the Tial waste gate ruptured resulting in maximum boost coming out of turn #1 at Summit Point Raceway. I had only been running 13 Lbs of boost before the failure. I am running a bigger turbo and stand alone engine management so even at 13 lbs the engine is making pretty respectable horsepower. The result was a catastrophic head gasket failure in #1 and #4 cylinders. It happened so fast that there was no overheating, just a lot of white smoke and a dead motor.

I was under the impression that the factory studs were intended for a one time use and should be replaced when the head gasket was replaced. Because the car is primarily a DE car I looked at this as an opportunity to upgrade to raceware studs.

I actually got all 10 studs out today using heat and either double nutting or welding the nut to the stud. It was a bitch but it was successful without damage to the block. I would also say it was probably a good thing as 3 of the studs had significant corrosion on them from 20 years of exposure. I don't know how long they may have lasted but I do know that corrosion fatigue is just as much a problem as stress fatigue.

I would like to thank everyone for their replys, I found a lot of useful information that I will apply upon reassembly. I will install a widefire head gasket with the raceware studs. Hopefully this gasket will last a good long time, I may even turn the boost up a bit.

Geoff