tomboyea123

I was going up the moutain toward the Eisenhower tunnel after watching the last pca race ever at 2nd creek raceway and I noticed that my temp gadge was about 7/8 toward the red zone so I pull over to let her cool down. As I slowed, I noticed steam cooming from the cap so I wraped a towel over the cap and released the presure. Everything seemed ok so after letting the shark cool off I get home and my oil light comes on and the car is leaking oil. I jack up the car and I find I have a 1 inch crack in the passenger side cylinder head starting about 1/2 of an inch below the valve cover.No coolent is mixing with the oil and I have good compression( I think).At this point I have several Question for some experienced shark lovers.Some might be a little stupid!Are there any really good 928 mechanics in the Denver area?Can these heads be welded or are there alloys that would prohibit this?Has anyone ever welded a head on the block before. It is accessable.(told you some questions were stupid!) Does anyone know of a 32 v head that is fresh? Are gt heads different than s4 heads other than the cams? What would a repair job like this cost from a-z?How big a job is it to do the job myself ( I have built several domestic v8 from the long block up but im a little intimadated by this one)Would it be better to look for a s4 engine and put my cams in it(might be cheaper in the long run) What would my good to excellent 45000 mile supercharged gt be worth with a cracked head? Also my renters burned down my rental house and I dont know if my finances or marrage can handle this kind of pressure right now as my better half doesnt really understand my weekness for toys. Thanks in advance!

tomboyea123

I might be interested in interesting porsche trades if I deside not to tackle this project. Thanks

Ron_H

Try this guy: (408)747-0728 Ted Robinson @ German Precision in Sunnyvale, CA. I would not want to weld a head on the engine.

SharkSkin

I agree with Ron. Anyone who would be willing to weld the head in place should not be allowed near the car.

John Veninger

Any 87+ head will work, but the 89-95 heads had a thicker casting in the bolt area to avoid cracking.

Sab

Sorry to hear about your mishap, shouldn't be too bad getting a used replacement head from the big three.
I think the head can be changed wiyhout the engine having to come out.

What kind of supercharger and how much boost where you running?

Ketchmi

We have a single head or a pair if you need, ported or stock, 89' and newer...not too far away. Give us a call tomorrow and we'll see what we can do to keep you in your shark.

hacker-pschorr

A friend of mine might be interested in the cracked head - he has welded up a block before so a head should not be an issue. Drop me a PM if your interested in selling after you find a replacement head.

tomboyea123

Thanks for the help to all. I have put ported heads on a ls1 engine and it used head bolts that could not be used again.I think the bolts stretched when used.Are the porsche headbolts reusable? My supercharger system is based on a FAST system and I run about 8lbs of boost.The head failure was not related to the boost but from the higher temp created by my small heat exchanger that I mounted in front of the radiator to cool my liquid intercooler(modified typhon unit).the car is a rocket with 517 rwhp but I have now learned that they should never ever be alowed to get past the 3/4 point on the temp gadge. Live and learn!

Ketchmi

We also have custom head studs that are the ticket for a supercharged GT...

toofast928

If the engine (head & block) got hot enough to crack. Entire engine inspection/rebuild is necessary. Especially if your boosted.

Cracked head = replaced head. All valves and valve seats need to be refaced. NOT LAPPED.
Replace all hardware, head studs/bolts.
Use a flat edge and check block deck and other head for flatness. May need machining.
Measure the cylinders, are they round or now oval.

Is expensive but when you do the same job over it's twice as expensive.

cfc928gt

Very sorry to hear about your misfortune. I'm not sure the temp gauge getting 7/8 to the red is the issue. I have an '89 GT and I used to occasionally get into the red, even got the first temp warning on a couple of occasions. Solution btw was to replace the oil thermostat. At any rate, I wonder if taking the cap off is what led to the cracking. If you were over hot and released pressure I would also think you would have lost a lot of coolant and then had air in the system.

As far as 928 wrenches in Denver, there are a couple. We have a 928 club in the Denver area called the Rocky Mountain Sharks and one of the members has a shop. There are also a couple shops used by some of the others who don't do their own work, all with good results although I don't know of any major repairs performed such as what you're going to need. We do have a member who just got his '87 back on the road after a timing belt failure who did all the work himself. Send me a PM and I can get you in touch with everyone. We'd also love to have you be a part of our club.

Bill Ball

Tomboy, you say you removed the coolant cap and let the motor cool down. You did not say if you left the engine running during the cool down. I trust you did, but at least for others who may face an overheated motor...

I agree with cfc928gt that generally speaking you should not pull the coolant cap. More importantly, do not turn the engine off unless you have lost your coolant from a big leak or the fans don't work. Doing either will trap heat in the engine.

If you turn off an overheated motor and pull the cap, you will usually have a geyser in short order as the trapped heat superheats the non-circulating coolant (BTDT). So, unless you have lost all coolant or your fans are not working, keep the motor running and let the circulating coolant cool the idling motor down.

WallyP

WARNING! HERESY WARNING!

If it were my car, and:
- I was certain that there is no coolant in the oil or oil in the coolant;
- Compression is normal in all cylinders;
- The crack is accessible;
- The car was a daily driver and not a show car;
then I would disconnect the ECUs, the dash, the stereo, and any other electronic gear, and I would weld the crack (with great care to avoid damage to surrounding areas and parts) and drive the car.

What do you have to lose?

HERESY WARNING OFF.

tomboyea123

Like you said, what do I have to lose! Not like i would hate to ruin a cracked head.Still not really Stuttgart textbook though.