Ed, is this copper? Or MLS?

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

SCE makes copper gaskets.

Lou

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Home of Slant6-powered fun machines

SCE Copper Gaskets are normally .040, but you can get them in different thickness. I bought one .060 because I needed piston to head clearance.

Doesn't the Cometic MLS have some kind of a stainless steel o ring around the combustion chamber that doesn't require grooving? I thought that was why they sealed so good.

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If you didn't drive it there, it's not a street car.

They have a proprietary embossed Viton coating on both of the outer layers of the gasket that is why they seal better.

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There's no such thing as too much cam....only not enough engine!

Also, I believe the sealing surface that hits the head and the one that hits the block can float somewhat independently. This apparently lets the head/block walk around a little and not break the seal.

I am not sure about this, but someone explained this to me at some point. Maybe a Mopax person or a racer mechanic like Tilley. Makes sense to me.

Best,

Lou

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Home of Slant6-powered fun machines

Just a little update to this thread. I had mentioned earlier that our Engine builder was checking into the Cometic head gasket again for our Slants. As it turns out they will do them, but at $330-$350 per gasket, and a minimum of 20. That price is just too high for most of us. Ryan is working with another manufacturer and we will start a new thread with the details if that works out.

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Rick, after speaking to you a few weeks ago about this matter, it should also be pointed out that the MLS style gaskets have their own specific needs to function successfully. Just as a copper head gasket has certain requirements and procedures that must be followed to perform without issues, an MLS gasket does as well. So before anyone pulls the trigger on committing to use one, just realize they are a top shelf product that also requires a top shelf approach to using one, and make sure you are willing to step up to this level of preparation required or you wont have a success story to talk about.

1) A much smoother surface finish is required, 50 RA or finer is required on both the block and heads deck surfaces compared to a regular head gasket or even a copper gasket, anything rougher than a 50 RA will conflict with the design of the gasket and will not provide positive sealing and will leak compression or water or both. Not all engine machine shops can provide this smoother surface finish that is required with their current equipment, so check before you buy one. You don't want to end up driving 200 miles just to get your block and head resurfaced. And shops that can do this usually upcharge you to do this as well. And yes, it has to be done on both the block and the head from the beginning and every time they are machined.

2) An MLS gasket requires a much flatter surface to seal successfully compared to a regular head gasket or even a copper gasket. In the past, everyone has pulled out their service manuals and looked for the specs of how much out of level a head or block surface can be using a feeler gauge and a straight edge. Well, with an MLS gasket, it has to be less than .002" over the distance of 12". This is much more precise than what a composition gasket can get away with, so every time you pull the head, most will have to have a clean up resurface done just so it will retain enough flatness to seal properly.

Given the tendencies of most Slant guys being on a budget, these extra steps of machining usually aren't even done when building their race engines, much less every time the head comes off and resurfacing the block just adds that extra level of costs they may not expect.

This isn't one of those parts you just pop the head off in your garage and swap gaskets, it is much more involved than that and requires a fresh cut on the block and head to even use for the first time.

Just make sure you are willing to follow these required steps for the successful use of this style of gasket. As Rick said, at a $330-$350 cost per gasket, you don't want this to end up being a wall hanger.

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There's no such thing as too much cam....only not enough engine!

Just ordered a copper gasket .093 thickest they have from Clark gaskets. They seem like awesome people husband and wife type of company.

It was funny on the phone both of them seemed surprised I daily drive this car with a copper head gasket. They both were like oh really you drive that on the street? lol
They mentioned I should only be using a 7lb radiator cap? I've never heard this before when running a copper head gasket? Any of you guys know why they mention that or have any experience with that recommendation?

Kev

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Copper doesn't have any real sealing qualities within itself, so you have to rely on whatever sealer you use on the gasket to seal the water ports. So it's probably just a safety net they recommend as to not over pressurize the cooling system and cause potential water leaks. Having said that, anyone that has used copper gaskets and experienced water seepage or leaks, it was likely caused from too much cooling system pressure as Clark has now pointed out 7 psi is the cap for pressure.

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There's no such thing as too much cam....only not enough engine!

Ya I figured it was for less pressure just seemed like it wouldn't make a difference if the gaskets was sealing with sealant on it, but I shall switch to a cap like that when I find one just in case anyway.

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When in race mode, most engines don't even run a pressurized water system, so leaking and seeping isn't really an issue in those applications when using copper head gaskets.

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There's no such thing as too much cam....only not enough engine!