Gm Head Gaskets

[uniquediesel]

The studs hold, they just allow coolant to enter the crankcase, so your lubricating system is unhappy.

One of the beefy bolt companies like ARP does make a set of non-tty bolts for the 6.5. Cometic sells these bolts (not studs) with their gaskets (or, I would assume, by themselves as well).

Honestly, if your making 300 Flywheel HP or less, use the TTY bolts, they're just fine and you don't have to worry about leaks. Every now and then there will be a "soft" bolt in the bunch, but it's really obvious during install when it happens (feels like the threads pulled down below).

 

[6.2 turbo]

My studs don't save the head gasket at all, I still wouldn't go back to bolts, but in mild applications it would seem unnecessary. Sounds like I will stick with silicone on the threads. As many head gasket problems these motors have its seems odd that everybody refuses to make a real one,my idea of a real gasket would be design and material like the 12 valve cummins gasket in a 6.5 gasket pattern.

 

[chevyCowboy]

My studs don't save the head gasket at all, I still wouldn't go back to bolts, but in mild applications it would seem unnecessary. Sounds like I will stick with silicone on the threads. As many head gasket problems these motors have its seems odd that everybody refuses to make a real one,my idea of a real gasket would be design and material like the 12 valve cummins gasket in a 6.5 gasket pattern.

do us all a favor and make one up!!!

 

[6.2 turbo]

I guess a gasket factory would have to do it. The only way I could do it my self would involve ,removing the cummins gasket fire rings and fitting them into the 6.5 gasket, but it wouldn't have a solid core.

 

[Anubis]

make the design and then get the gasket companies to make it

 

[6.2 turbo]

I would have to find a custom gasket place, the big guys would probably not be interested, next problem is money. Gasket Works USA can make me copper ones, but almost every one says copper gaskets leak water, also the price of copper gaskets and oringing would be a lot.

 

[chevyCowboy]

o come on for the betterment of the 6.5 community find a way and well help you convince the "big" companies to market them.

 

[NCadam]

a better head gasget would be sweet!!! so what would be the best gasget for about 18 pounds of boost???? (intercooled and head studs)

 

[6.2 turbo]

Victor Reinz 4021T the T is for.010 thicker, these should be able to hold more than 18 psi boost, when I had these they held untill I hit 60 psi, this was with stock head bolts. Though they were torqued till they wouldn't go any more, since then I have learned how to torque a head bolt or stud way past the yield point,not recommended but can be done, I had the arps at 150 ft lbs on the 6.2 and my cummins stock stretch bolts are at 135 ft lbs,they also use a 12 mm 12.9 grade bolt, the last time I torqued the 6.2 to 135 ft lbs I might go higher next time, ARP recommends 130 with 30 wt oil or I think 110 with moly I did the 150 with moly, you will probably pull these studs out of the block before you'll snap one. I don't recommend any one to go more than 130 with moly lube.

 

[NCadam]

where is the best place to get the vicot rinz gasget at?

 

[6.2 turbo]

Napa used to have them, now they are harder to find, Motor Parts Central has the 4021 and 4021T in their online catalog, my last ones came from ebay, these were 6.2 gaskets though.

 

[Goldsburg]

Victor Reinz 4021T the T is for.010 thicker, these should be able to hold more than 18 psi boost, when I had these they held untill I hit 60 psi, this was with stock head bolts. Though they were torqued till they wouldn't go any more, since then I have learned how to torque a head bolt or stud way past the yield point,not recommended but can be done, I had the arps at 150 ft lbs on the 6.2 and my cummins stock stretch bolts are at 135 ft lbs,they also use a 12 mm 12.9 grade bolt, the last time I torqued the 6.2 to 135 ft lbs I might go higher next time, ARP recommends 130 with 30 wt oil or I think 110 with moly I did the 150 with moly, you will probably pull these studs out of the block before you'll snap one. I don't recommend any one to go more than 130 with moly lube.

Bare in mind that you can distort the deck from over-torquing the head bolts and studs. Perhaps this is where part of the issue lies with blowing gaskets...

I think that you need to contact Lubbock gasket and have them make you a k1000 gasket that will accept a drop-in double-jacket steel fire ring for the 6.5. If that doesn't hold, you could then switch to a "C" ring for an insert. You will likely split the block in half before blowing one of these out.

But what the hell do I know? Not nearly as much as some of the "experts" on this board...

Regards,

Goldsburg

 

[SmithvilleD]

I was just discussing that thought w/ somebody regarding the GEP optimizer. Wasn't part of the GEP/Navistar cast block's redesign adding some material thickness in the deck & specifically around the head bolt holes?

Trying to eliminate the upper cylinder cracks that have happened sometimes on the rear cylinders?

 

[chevyinlinesix]

Bare in mind that you can distort the deck from over-torquing the head bolts and studs. Perhaps this is where part of the issue lies with blowing gaskets...

I think that you need to contact Lubbock gasket and have them make you a k1000 gasket that will accept a drop-in double-jacket steel fire ring for the 6.5. If that doesn't hold, you could then switch to a "C" ring for an insert. You will likely split the block in half before blowing one of these out.

But what the hell do I know? Not nearly as much as some of the "experts" on this board...

Regards,

Goldsburg

 

[6.2 turbo]

I will give Lubbock gasket a call. I'll check my block and heads with a straight edge, once I get the heads off.

 

[6.2 turbo]

I called Lubbock today, they are having a hard time getting asbestos, he thought I might need copper gaskets.

 

[buddy]

When you install the head studs and nuts, is it common to torque it down then pull it back up and do it again? I have found in a lot of things that retorqueing some things will result in it going down more threads and make the holding pressure it was intended to.

 

[6.2 turbo]

The Cometic guy had suggested that I loosen them and retorque,I didn't though. Molly lube will eliminate false torque readings from the nut binding on the threads and washer. I also noticed if your maxing a head bolt or stud and its just stretching,wait a few seconds and torque again, it seems they settle a bit ,this is most noticeable on tty bolts. It probably wouldn't hurt to retorque after the motor has been run for a little.

 

[buddy]

Cometic makes their gaskets custom, so you might get them to beef up an area on request, for a price of course. I mean they are already $140 each and they claim reinforced in places for high boost applications. When you used the Cometic you put it on dry right? Its not suppose to use any gasket sealant or it will mess with the sealant that comes on it.

 

[6.2 turbo]

They are supposed to go on dry,I used sealer. I think mine were closer to $90 each from Summit. The problem is once you have a compression leak it will take off the coating,and never seal again. I think it would be be better with no coating,and more thin layers,and the top and bottom layer to not have full coverage.