Thread:

Another head gasket question

The early Felpro MLS gaskets had a sticky nitrile coating on them that made them much less sensitive to the deck finish, but now the Felpro has EXACTLY the same coating as the cometics.

But, Mr Gaskets MLS does still have the nitrile coating like the old Felpro. The deck finish is much less critical. So if you still wish the run a MLS, I would consider them.
Any MLS will work better with less than perfect finish if you coat them with some sealers. The GM gasket sealing compound was developed by GM for the Turbo V6 Buick problems and works great, as does Mopar's spray sealer. I wouldn't use it on a Mr.Gasket MLS for the first use, but I have used it for re-using a gasket.
You should be able to get either at any dealership.
Link GM sealer

LINK: Mopar sealer

well I just went through the crap.....It is not recomended to use a mls gaskets with o-rings. The reason is the process of thermal expansion..the block side layer of a mls gasket is locked by the o-rings and can not move, while the other layers move with thermal expansion. Mls marine gaskets are stainless...o-rings are stainless.....guess what happens..and mls gaskets are not recomended for boost levels above 16psi....its back to copper for me

Originally Posted by tkriley13

I run a dart block it isnt O ringed and the machining surface on the block/heads has groves not perfectly smooth and I`ve been told the MLS gasket will never work long with that type of machining process. so before I tear this thing down and have it O ringed I want to try the ICS by SCE cooper head gasket.

Thanks for the help, Tom

Who said anything about running a MLS and O-rings. I shorten the OP's post so that you 2 could hopefully hang in long enough to get what he was REALLY asking.

Surprised neither of you mentioned that you CANNOT use O-rings with the ICS gasket either.

Originally Posted by Michael Thomas

well I just went through the crap.....It is not recomended to use a mls gaskets with o-rings. The reason is the process of thermal expansion..the block side layer of a mls gasket is locked by the o-rings and can not move, while the other layers move with thermal expansion. Mls marine gaskets are stainless...o-rings are stainless.....guess what happens..and mls gaskets are not recomended for boost levels above 16psi....its back to copper for me

Is that 16 psi at 12 to 1, or 16 psi at 8 to 1.
I've seen MLS gaskets handle considerably more boost than 16 psi.
But like the OP stated, if the deck finish is not right, they are next to useless. Specially the Cometics and the later Felpros.

Bob, I see that you are up from your afternoon nap feeling frisky...sorry I can't give you cylinder pressure at those compression figures...I haven't quite figured how to adapt a Keen indicator to a gas engine to give you the bmep figures that you will be asking for.

I wasn't asking for specific cylinder pressures. I was just curious who and how that boost presssure was determined to be the MAX limit for a MLS gasket. I have run 15 psi with a Felpro composite performance gasket before. But then, it wasn't on 12 to 1 alky motor.

The MLS is more than capable of taking just about anybody here can throw at one. Its very seldom the gasket that failed, as much as the person that installed it that failed.

I see your point...I had spoke to a couple of techs at the manufacture, and the 16 psi number did not come with f/c...But as you posted read the directions that come with your head gaskets...mine had them, but I guess the machine shop could not read the warning in bold letters.

Originally Posted by tkriley13

Another disappointing weekend for us! what I thought was too much oil the last pass I made last month (cause I added 2 extra quarts since I dont run a dip stick and I had an oil leak) was the head gasket on the even side going away and blowing oil out the breather. My boat was running in the pits before I took it over to tech it and it wouldn`t start again. I run a dart block it isnt O ringed and the machining surface on the block/heads has groves not perfectly smooth and I`ve been told the MLS gasket will never work long with that type of machining process. so before I tear this thing down and have it O ringed I want to try the ICS by SCE cooper head gasket. do any of guys have pro`s and con`s about them or the installation process? Keep in mind I`m a union electrician not an engine pro like a lot of you guys but I do all my own stuff and maybe this is the learning curve but I enjoy doing my own stuff and with the hopes of one day setting the world on fire so I can be proud I did it myself and didnt pay a butt load of money to someone else but to be honest, I`m almost there with paying someone else since I`m throwing money away when I head to a race and it doesnt run or just more problems!!!

I brought a leak down tester a few weeks ago and I guess its time to start using it cause I`m sure it would`ve told me something was wrong before I went to the races. I tired to find some in town saturday morning but with the larger bore stuff Bako doesnt have those kinds of speed shops or I didnt find the right place but I thing I call ever where and tried places locals told me to try. Oh well thats racing right? hate that saying

Thanks for the help, Tom

Tom, man I feel for you bud!! Give me a call and lets see if we can come up with some ideas....

Originally Posted by gn7

The MLS is more than capable of taking just about anybody here can throw at one. Its very seldom the gasket that failed, as much as the person that installed it that failed.

This right here...

Originally Posted by Michael Thomas

I see your point...I had spoke to a couple of techs at the manufacture, and the 16 psi number did not come with f/c...But as you posted read the directions that come with your head gaskets...mine had them, but I guess the machine shop could not read the warning in bold letters.

I can remember back when running the old shim steel gaskets that having a surfacewith "tooth" was thee setup. Seems many machinists still do. Composite gaskets are a little forgiving for agressively pushed cutters and overly tilted cutter heads. Both will fail a MLS right now! Like I said, the old Felpro and the Mr Gasket will deal with it better than a Cometic, but not by alot.
In the end, any gasket has a much better chance of surviving harsh conditions like a blown deal with hi cylinder pressures if the surface is as dead nuts as you can get it.
I have seen copper and o-rings give guys fits, and others will not use anything but. Personally, if I can avoid them, I do.

I recently bought a set of SCEs with the ICS. I haven't run them yet, but I have heard they work very well in high boost turbo deals. I much perfer to have the O-ring built into the gasket if possible. It seems the guys that run insane boost do as well, or Cometic would have never developed the Phusion series. If you blow one of those, you need to check you studs to see if they stretch as well, or if you still have threads in the block.

I hear of guys running 30# with Cometics. It's more a bout the flatness of the decks and heads than the finish, but the smoother the better. A lot of head surfacers have the head tilted so the cutter doesn't back-drag, but unfortunately this creates a concave cut across the blocks, and puts the low spot in the absolute worst place...right down the center, between cyl's. Most guys throw a straight edge across the deck from end to end and will tell you it's flat, but never check from top to bottom. Best to check with your machinist and see just how his cutter is set up. A little back drag on the cut doesn't hurt a thing and ensures the cutter is cutting flat. With everything right, I wouldn't hesitate to run the Cometics. I understand that some guys just like O-rings, but that brings with it's own can of worms.
JMO