DanD

Ok, I'm not really getting where the problem is. I have the same headgasket. I see a rib separating the water jacket. Maybe someone can draw some 'circle and arrows' to help me understand.

Here is the area in question on my block. Notice I have a broken bolt in the water jacket hole. God was smiling on me as it came out with just some soaking and vice grips.



Thanks,
DanD

AlexE

There should be a barrier where the red is....

Coolant can migrate to that bolt hole....rust out the hole or the coolant migrates up the bolt and leaks out if its bad enough..... all the other bolts have barriers around them..... take a look at the metal pic I posted its really obvious on that one.

P.S and I just noticed.... same thing happened to yours that happened to mine.... The bolt is rusted out! and snapped off.

DanD

Thanks AlexE,
I see it now. I was fortunate, mine came out. I'll take care on reassembly.
Thanks again Tony for bringing this up.
DanD

Jon Schepps

Having recently installed the Cometic gasket, but only run car a few miles, is this potential leakage path worth pulling the head pro-actively to apply the sealant?

If not, will I be able to see if its leaking or starts to leak in the future?

Jon

TonyG

Jon Schepps

No.


Wait until the next time you pull the head.

What you might want to do though is to use a stainless bolt for that back bolt hole just in case water does get there (so it won't rust out and break in the future).

TonyG

Danno

"Having recently installed the Cometic gasket, but only run car a few miles, is this potential leakage path worth pulling the head pro-actively to apply the sealant? "

No worries, you can remove just that one bolt and coat it with some sealant and re-install. Also on the washer and you should be OK.

Here is some more information on sealing headgaskets and engine-cases:

http://www.blueglue.com/archives/vin.../msg00402.html
http://yarchive.net/car/turbo_head_gasket.html
http://brickboard.com/ARCHIVES/1998MAR/50000094.shtml
http://www.coperacing.com/agprev60.htm (scroll to question#55)

BTW - The Cometic gaskets made for GURU are not the same ones you can get from Cometic or PD. Neil himself told me to use Coppercoast spray on these, but not the Cometic ones...

Tony

Curious...
What is the difference between your cyl bores and gasket bores?

thanks

fortysixandtwo

The bolt won't rust. But the galvanic corrosion between aluminum and stainless steel, will corrode the block.


46&2

Danno

"What is the difference between your cyl bores and gasket bores?"

About 0.5mm all around. So the gasket bore is 1mm larger than the cylinder.

A good site for headgasket info: Gasket Works

AlexE

ugghhhhh .............. ok now I am getting confused..

could there be something different with the surface of your gasket???? ............cause I have yours Danno..... and my head is nicely torqued down without having used the copper spray....

...and the engine is scheduled to go back in the car at the end of the month.... so a little clarification would be highly appreciated.


Thanks!

TonyG

>>>The bolt won't rust. But the galvanic corrosion between aluminum and stainless steel, will corrode the block.<<<

Interesting. Ok... learn something new everyday. Although I have stainless fasteners though out my engine now. No signs of corrosion on the block yet....

Go figure...


TonyG

TonyG

>>>"What is the difference between your cyl bores and gasket bores?"<<<

A stock head gasket measures out at a tad over 102mm thus the answer is 2mm on a stock bore of 100mm.

TonyG

dand86951

Porsche kept the 2mm over bore size for the 2.7 litre engine as it is 106mm compared to the 104mm bore.

Jon Schepps

Tony, Danno,

Thanks. I think I'll go with sealant on a stainless-steel bolt, and keep an eye on it.

Jon.

DanD

I think I'll opt for the Stanless bolt. Mine certainly was damaged enough to break off with little effort. I took it out with a pair of plyers once the head was off. No thread damage.

Got the Coppercoast spray and the head goes on tonight!