*eurospeed951*

Here are the links to my head gasket pics. I just removed the head and gasket a few moments ago. The reason for removal, was because I was haveing an overheating problem. Every time I got on boost I would get air in my coolent system. I thought that this might be from a bad head gasket. This is on my freshly built 106mm bore 2.8. When I removed the gasket I could not see any major signs of a leak. There are a few spots that look a little weird, but I'm not sure. The pics are big so you can see the detail.
Head Gasket pics

Jeff Lamb

I viewed the pictures of your head gasket and I am not sure if I know why your engine is pressurizing your cooling system, however, I did notice a few things that I wanted to ask you about:

1. Is the inside diameter (ID) of the fire ring of the head gasket smaller than the ID of the 106mm bores? From your pictures it looks as if this is the case. If so, the fire ring sticking out into the combustion chamber will make it prone to failure.
2. Your cylinder head combustion chamber area has not been enlarged to mate up to the 106mm bores. This causes a sharp edge during the transition from the bore to the head. This sharp edge can cause a hot spot and related detonation.
3. Piston tops #2 and #3 look like they have potentially been "steam cleaned" a little bit. If you had a slight leak in the head gasket, this could allow some coolant in and also allow compression gases out (to pressurize your cooling system).
4. Pistons #2 and #3 (and to a slight extent #1) appear to have some "gunk" in their dish areas. What is this?

Jeff

Mike S

I had a similar problem on mine, except that I also had some occasional white smoke in the exhaust. My head gasket looked just like your with no signs of detonation. However, when I pulled the head the middle nuts were not torqued very tight and I thought that the head may have been lifting a bit. Check the height of your studs to make sure that they are all the same. If not a couple may have stretched.

Also, after my rebuild I had things running again and I started getting the same overheating problem...this time without the white smoke. Four weeks of tracking it down and one replacement temp sensor later...I found the problem. I had a bad ground. The instrument panel ground wasn't working well and neither was the ground for the motor. We added a ground strap from the bell housing to the chassis(near the front a-arm) and that solved the problem. I finally figured this out when I noticed that the overheating problem was occuring when the front fans went on. When the fans were off I had no problems at all.

Hope that helps.

m42racer

Yes you did lose your H/G. Take alook at the gasket cyl 1. It blew right into the water gallery. You can see in the chamber where it was blowing.

Can I ask why you still have the plugs in? The very firat thing you should have done was a leakdown.

From your engine spec's I expect you are not running stock boost. I see you have Raceware studs. It has been stated on this forum before about the design of Raceware and the stock studs. With studs of this design, you must always check the torque. As they are not a proper stretch bolt, all of the torque goes into the threads. I expect you have had the typical head lifting problem.

Get a MLS gasket form Guru, resurface the head etc, and you should be ok. If you do continue to use those Head studs, use some anti friction grease/oil on the head nuts, under the washers etc, and retorque them. The proper way is to measure the head thickness and make up spacers the same thickness as the head, then torque a stud. You can then measure the stretch of the stud. Just make sure the spacers don't crush.
You will find the threaded end in the block will do all the stretching/pulling, so be careful. The amount of torque is based upon the stretch. With plenty of grease, torque to the manufacturers specs. Measure, then redo but this time torque to about 20ft/Lbs. Then turn nut 45 degrees. Re measure the stretch and the torque. Keep turning the nut to now a total of 90 degrees if more is required. This way will remove any friction from giving an error in torque. What you want to see is even stretch on all studs and a final torque approx what the stud manufacturer recommends. Often you can go another 90 degrees without any problems. Be careful.

Chris Prack

I would agree that the head is lifting. Did you retorque the head after one no load heat cycle. This is very important. My other post to you was......

" I would not waste my time installing the head studs if you don't plan to retorque the head. You WILL blow the head gasket if you do not.

You need to make sure that the engine is stone cold (like overnight) before you retorque the studs. You also need to install all of the studs at the same height, this in important so you get good thread contact on both ends of the stud. I want to say about 75mm above the deck if I remember correctly. I can check my note book and say for sure.

A cam housing gasket is only about $10 and your time but there is no other way to do it properly. "

Get a new head gasket, clean up the head and try it again. I think that will solve your problem.

BC

Does someone here want to interject on what other head studs people like using? I called ARP and they simply want me to see if the length and thread is something they already make.

Rod bolts is the same issue.

Who do we have to choose from?

(My rod bolts are the same as yours)

Chris Prack

Raceware makes head studs, rod bolts and main stud sets specifically for our cars.

Chris Prack

Go here http://www.raceware-fasteners.com/products.htm

BC

Well, I appreciate that link, but he doesn't do the longer "studs" that I would need for my 89 heads (Its a 928, but you guys are a bit more "active" with the custom ideas in here).

fast951

Great advise from everyone. I would check the block as well, make sure the sleeves did not move, something they are known for.

As for the head studs, I always use the factory studs and follow the recommended torque sequence and values. I use the widefire ring gasket, Oringed head. I ran as high as 25psi on the dyno for many many runs (torture test) and I tracked my car with boost in the 20+ psi. Never a blown head gasket...
[I do not recommend you run this kind of boost! Just stating my experience]

TurboTim

I wasnt able to look at the pics?

TurboTim

We have used Raceware and ARP headstuds with great success.Regardless of what is reccomended, we do not re-torque the headstuds after the initial torque.We do use a different final torque spec then Raceware reccomends. Never had a problem and we have installed about 20-25 sets of these over the years.Now we are also using a metal head gasket that we sell and it is awesome.The only downside is that your motor will go before the headgasket lets go!

Danno

Of those two, I would recommend the ARP studs over the Raceware any day!

Chris Prack

Why is that? Just curious.

m42racer

Amen to that Danno.

Raceware, a very clever marketing program. Coat very standard material with coating and sell as high end fasteners.