MLS Head Gasket Coatings/ Sealants

[SS4REAL]

I am going to put back together my SBC. It is 427 ci Motown block with
Dart pro1 alum. heads. Compression is 9.8:1 and I am using
a Vortech s/c with appox 8 lbs of boost ( I know, too much comp. but i"m
in a pinch to get ready for drag week)
To the issue: I've decided to use the MLS Cometic gaskets. I've
read on some forums to use a copper coat, Cometic says to install
dry if a good smooth surface and lightly coat with copper spray if a rough
surface...
What are your opinions / experiences with MLS gaskets and leaking/ sealing. ???

[SpiderGearsMan]

Re: MLS Head Gasket Coatings/ Sealants

O RING IT !! Copper head gaskets

[CDMBill]

Re: MLS Head Gasket Coatings/ Sealants

I had my block and heads surfaced according to the Cometic spec, almost a polished look and we had seepage issues on the dyno simply by putting the water in the engine, no pressure. With low pressure form the dyno feed system they seeped a bit more. We tried Copper Coat spray which didn't help. So we pulled the heads again and used the conventional Fel-pros with Copper Coat. No issues after two years. I did have to pull one head due to a very bent push rod and used a new Fel-pro same technique, no issues.

I have ben told that the Cometics will seep until heat cycled a few times. perhaps we were too paranoid but....

The OEM's use MLS gaskets now and Fel-pro and others also offer them so the technology is obviuosly sound. Just our experience two years ago.

[min301]

Re: MLS Head Gasket Coatings/ Sealants

Also, the use of Permatex brush on sealer is recommended, by me, and a
number of folks who use the MLS gaskets.
I believe Nelson uses that technique as well.

[min301]

Re: MLS Head Gasket Coatings/ Sealants

I have, but only on stock stuff.

[SS4REAL]

Re: MLS Head Gasket Coatings/ Sealants

Also, the use of Permatex brush on sealer is recommended, by me, and a
number of folks who use the MLS gaskets.
I believe Nelson uses that technique as well.

Which sealer do you use??? Do you have a part # or a specific description so
I can locate it at my parts store (they can order any of the permatex products)

[min301]

Re: MLS Head Gasket Coatings/ Sealants

I'll get it for you tomorrow, I have it at work.

[SS4REAL]

Re: MLS Head Gasket Coatings/ Sealants

Thank You
I'll check back here Monday

[min301]

Re: MLS Head Gasket Coatings/ Sealants

It's Permatex super 300 sealer.
Put it on the gasket(both sides), and both sealing surfaces.
Torque it, heat the heads(hairdriers work, blowing into the coolant passages)for a while,
then loosen, and retorque.
Good stuff!

[jaybnve]

Re: MLS Head Gasket Coatings/ Sealants

I'm surprised to read about the problems with Cometic head gaskets. I've been using their MLS gaskets on my FEs for four years or so, with no sealer and whatever block/head surface happens to be there, with absolutely zero issues. No leaks or blown gaskets on anything (engines ranged from 400 to 1200 HP), and I've re-used the gaskets on more than one occasion simply by cleaning them up with brake cleaner and re-installing them. Go figure ???

[min301]

Re: MLS Head Gasket Coatings/ Sealants

Surface texture could have alot to do with that.

We all have specific taste's in some respect,
to bore finish, and how it interacts with oil, and the ring pack.
this is the same kind of thinking.

We know that the surface is supposed to be treated accordingly,
but differences in machine shops can cause wildly differing results.

[Tommygun]

Re: MLS Head Gasket Coatings/ Sealants

8lbs and 9.8:1 is not something I would worry about.

Stock 4.6L mustangs have 10.1 and run 12lbs with no problems

I have had problems sealing MLS gaskets on SBFs and had to use copper coat spray

[miketblsr]

Re: MLS Head Gasket Coatings/ Sealants

You should try felpro's new permaseal mls gaskets. They come precoated. Dave and I put them on the camaro and they are awesome no leaks at all. We are about to reuse them again after an engine tear down and will be using copper spray when we go back together to help seal some of the spots whear the permaseal came off upon removal.

[min301]

Re: MLS Head Gasket Coatings/ Sealants

You should try felpro's new permaseal mls gaskets. They come precoated. Dave and I put them on the camaro and they are awesome no leaks at all. We are about to reuse them again after an engine tear down and will be using copper spray when we go back together to help seal some of the spots whear the permaseal came off upon removal.

I wouldn't re-use em, but thats just me.

[miketblsr]

Re: MLS Head Gasket Coatings/ Sealants

At 100.00 each I'll reuse em. They are reusable last time I check. I thought all Multi Layered Steel gasket were. Maybe Im wrong and the TIME BOMB will once again live up to its name. Maybe not!!!!!! Only time will tell, if Dave decides to put it back together again of course. :-\