(Re)coating MLS gaskets prior to reuse

I need to pull my heads to replace the short rocker shaft studs with longer ones. It was one of those things that I didn't manage to get done and stay on schedule for the dyno session.

The Mr. Gasket MLS gaskets I used come with some type of coating that's supposed to help them seal. Disregarding the fact that some of this coating was already coming off the gaskets when I removed them from their packages, I'm interested in reusing them. I'd appreciate recommendations on what I should apply to these low-use MLS gaskets before putting the heads back on.

Thanks - Brad

Copper coat spray.

Spray Hylomar. Basically the same coating the FelPro 1009 head gaskets have in spray can form.

You should be fine putting them back on dry but some people coat them. I always use them dry.

Never had any luck with the cheaper Mr. Gasket MLS - they would not re-seal even sprayed with copper tac. On the other hand the cometic gaskets - we just carefully wipe down with solvent and re-use - no issues!

Done Cometics 3x dry now. Never an issue.

OK, that strikes me as kind of odd... and disappointing. They certainly didn't COST any cheaper than Cometics, and were supposed to seal better.

FWIW, Mr. G says they are "nitrile-coated". But as I mentioned above, the coating had peeled/flaked off some parts of the gaskets when I pulled them out of their packages. Struck me as kind of a half-a$$ed coating if it didn't survive even that long.

Yep

I see now they are actually cost more than cometics - used to be they were about 2/3 the price of cometics - throw them away and get some cometics you will not regret that move

3rd time around on mine. 15-1 no issues. I used copper spray. Did it need it? Don't know. I do know they don't leak, 550 passes.
Doug

Cometic or Mr. Gasket?

Cometic

Spray some Copper on them and don't worry about it again.

Bump from a few months ago...

I pulled off the heads yesterday and, although I can't say exactly why, I'm not sure that those Mr. Gasket MLS head gaskets actually sealed properly. I can't put my finger on it, but I think it's because they both looked kind of wet (coolant seepage?), which didn't seem normal to me.

The purpose of using MLS head gaskets in the first place was because the re-hone as part of this build didn't use torque plates. The machinist said the existing .060" oversize bores distorted too much with the torque plate and did a quick touch-up hone w/o it, so I figured an MLS would reduce some of the distortion vs the typical composition gasket I'd use. The block & head surfaces certainly appeared smooth enough to use an MLS, especially w/ Mr. Gasket saying their nitrile coating was more forgiving of surface irregularities.

Haven't decided on the best option for when the heads go back on:
1. Coat the Mr. G MLS parts w/ "something" and re-use them (and does this require disassembling them and coating all the layers?)
2. Buy a set of Cometic MLS gaskets, since they seem to have a better reputation in this thread
3. Use some of my tried-and-true orange Detroit Gasket "Competition" composition head gaskets

Thoughts?

One engine I had built had Mr. Gasket MLS gaskets and I was told that they seeped until after the initial engine break-in/heat cycles even though the surfaces had the proper finish. It sealed ok for the short time I ran it, but after I got water in the engine from another problem, I switched to more conventional composition gaskets for peace of mind on my 360 (Fel-Pro 1008).

What REALLY caught my attention was your engine builder not honing with torque plates because he said that the +.060" walls were too thin and distorted too much with a plate. The whole purpose of torque plates is to simulate the heads during the honing process so when the heads are actually bolted on and stressing/distorting the block, the bores remain round! (Some also use the same type of gasket to help duplicate all of the influential factors.) I'm not sure how much the deck plate affects head gasket seal, perhaps a little, if any, but it certainly would affect the ring seal.

NOTE: Are you saying that the initial build didn't use torque plates? I would be curious how much, if any, a head gasket style affects the deck even though it can't hurt to use one during honing.)

OK, so I think I should provide some background so it's clearer to anyone who reads this.

1. EB (Engine Bulder) "A" provided a prepped & assembled 4.375"-bore 440 short block for me after I destroyed my previous one when I threw a rod at the 1000 ft mark one night. EB "A" was supposedly a "Mopar Guru". I wiped a cam in that build after about 1200 miles (another story in itself) and he re-honed it due to the cam debris having messed up things. I found out much later that he "doesn't believe in torque plates". No, I don't know why in this day and age anyone would have that opinion...

2. When that (re)build was torn down to be freshened up, etc., EB "B", who was MUCH closer to me than EB "A", said the bores were too loose and he recommended taking it out from 4.375" to 4.380". He ordered the pistons for me and charged me (I still have the receipt) to do the cylinder hone finish work WITH a torque plate. I did the assembly of that engine, although EB "B" did the short block machine work and Dwayne Porter did the Stage VI heads I switched to.

3. I ran the block that EB "B" prepped for me until I had an oil system eff-up that required me to tear down the engine again. EB "B" had since relocated (or closed, not sure at this point, and don't care), so I asked around for recommendations for someone else close to where I now live. That brings EB "C" into the story.

4. EB "C" had a good rep, so I took my stuff to him to have a touch-up hone done as part of this rebuild. He asked me for the history of the block, and I told him what I knew. He calls me later and says, as best as I can remember, "Well, EB 'B' may have put a torque plate on the block when he honed it, but he sure as He11 didn't bolt it down. The only way these bores are round is if the plate is left off, and they won't clean up properly with the plate on at this bore because of the distortion." It was at this point I went and verified that EB "B" DID charge me for honing that block w/ a torque plate, even though it certainly sounds like he didn't.

5. So, EB "C" and I talked... He was also doing the full prep work on my spare 440 block, so we decided to just hone the first block w/o the plate (it had obviously been running that way for quite a while). At least that way I could put the 4.380" short block back together while I was still collecting the rest of the parts for the freshly machined 4.375" 440 block to replace it.

The somewhat amusing thing is that this same well-used (or "tired", as I recently called it) short block made as much HP and torque as it did, despite having .003" too-loose piston-to-cylinder wall clearances and "not round" bores. And, yet, I don't know that the next build with the properly-machined block, new pistons, etc., would actually make any more power when assembled with the same heads, cam, etc.

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Some tech magazine I read years ago had an article showing how different head gasket designs / compositions changed the way the bores distorted. An MLS construction resulted in noticeably less distortion than a composition gasket in their example. That was one of the first times that I heard how it's important to use the same type of gasket during the actual engine assembly as was used during the plate-hone operation.

I spray them with copper coat and use them. Yes you need to take them apart to clean them properly

I would use a new set of cometics and move on - not worth taking it apart again if they do not seal - you are experiencing exactly the same thing I did with the Mr. Gasket MLS head Gaskets

I cleaned mine thoroughly but never use copper coat. I think you will be happier with the Cometics.

I don't think I would try and separate the MLS gaskets. Also I prefer High Temp 1200 or 1500 Aluminum ceramic paint.

But in your case, with the stock coating flaking off, done/gone get rid of them.

You drill out a rivet, not like its complicated. I would NEVER reuse thme without cleaning them. Only way to clean them properly is to drill out the rivet and separate them to clean them. Maybe its the difference between compression ratios above 15-1 but I have NEVER had an issue taking them apart and cleaning them, then using copper coat on the outer layers. I've never used a Mr Gasket or anyone else's MLS gasket except Cometic. But they will tell you to either NOT reuse them or to wipe em off and never use anything.

Heck I had to drill out 3 rivots and cut part of the gasket on my Keith Black block and B1 head combo. No big deal. The rivets wouldn't let my head seat properly.

I just use new gaskets whenever I pull the heads off. Easier that way....

Same with me, so you're basically there already

Yeah the rivets on the Cometics get in the way of MOST Mopar heads. I have none on any B1 stuff or the Predators.

We just put a small counterbore in the head or the block to clear the rivets. Then we never have to drill out the rivets.

Additional evidence that the Mr G. MLS gaskets weren't sealing properly: Half of the cylinders have corrosion in the bores where the moisture collected above the ring lands on the outside walls while the pistons remained in the same position for weeks after the dyno session.

NOT impressed.

I tried the MR Gasket MLS gaskets once and then went back to Cometic. It also helps that I get a nice discount from Cometic. Mr Gasket is such a big company they don't care about little guys like me.

Mr. Gasket use to have their MLS gaskets made here in the U.S., not any more now that there made in China
I have reused the Cometic dry as well as coated with Copper Coat, they worked both ways with no issues that I saw

I've never re-used a head gasket before. The Mr. G's were new and they simply didn't seal properly.

I may consider some new Cometics, or save my money and use one of my remaining sets of the discontinued orange DG gaskets I mentioned previously. The only real issue I had w/ those is they're a big PITA to clean off the heads & block when disassembled... but they sure as He11 didn't leak.

Guess I must have purchased Chi-Com-etics.

I think it was around three or four years ago that one of the Mr. Gasket manufacturer reps. told me that they had quit making those MLS head gasket here in the U.S., this was after I called them about having to wait 2 to 3 weeks to get them from Summit

Did at any time leak down that engine??
I'm lazy,just bought new ones..........

""Only way to clean them properly is to drill out the rivet and separate them to clean them.""

When doing this, I am assuming that you have to reassemble them on the same head and in the same order? Is this correct?

Thanks!

I bought a set of Mr Gasket mls gaskets from Jegs once and they came in a Cometic package cardboard insert, with a Mr Gasket sticker on them, that must of been their once upon a time american supplier before they went with wang chung gasket company.

That's my understanding as well.

I bought some Mr Gasket MLS gaskets in the summer of 2014 and they looked just like some Cometic 340 gaskets I have. I just had one start to leak coolant (I never re-torqued them) I removed the bolts one at a time in order and lubed the threads and re-torqued them one by one and it stopped leaking.

With a quality fastener like ARP you can go 5 or 10 more # in tq to help stop any leaks so going from 70# to 80 would be ok.

FWIW, I have decided not to reuse the Mr. G MLS head gaskets. I have a few sets of the old DG composition "race" gaskets that never caused me any problems, other than being a PITA to clean up after disassembly.

I'm on the 3rd time around on mine. BB, 15-1,-1 heads. Split them up, clean, copper coat and go.
Doug

When people spray coat them is it only on the surfaces facing the block and heads? Or does each layer get coated?

I personally did them all.
Doug

Guys
Coppercoat was made way back in the day as yes--a sort of sealer with the copper added to promote heat transfer with Steel Shim head gaskets
It is not the right product for the way you all seem to use it
The spray can Hylomar is the best head gasket sauce in the world--I have re-sprayed Cometics three/ four times and kept on using them--it restores the ability to seal the water--that is all it does
The Mr gasket multi layers suck!! Use Cometics or else
And if you do use steel shim gaskets the Hylomar is ten times better than CopperCoat--why don't you just use some Indian gasket sealer while you are at it

I had to drill out one rivet on my small block x heads 360 block, the rivet got pinched between the head and block. Cometic gaskets. Caught it just as I was about to torque ut down!