MLS Head Gasket not sealing - Options?

[Enraged78]

Hey all,

Previously, I've had some random misfires and cold start problems that I thought were ignition problems. After going through three ignitors, two DSMLink chips, eight plugs, and two coil packs, I finally looked at weather or not my Mitsu MLS head gasket was sealing properly. I used a gas analyzer at the filler neck, and found that I have exhaust gas leaking into my cooling system. Not good. The leak is not very large, and it's not a blowout, so it was fairly elusive for a while. Sometimes on rare occasions, the engine will dump some coolant out of the overflow bottle. I thought that this was due to an air bubble or leaky clamp in the cooling system. Wrong on this one as well.

Anyway, now I have to fix it, so I'm examining some of my options. My mods are in my profile, but here's the skinny: 7-bolt block, Ross 8.5 to 1 pistons, Eagle rods, no balance shafts, rotating assembly balanced to .02 grams. Head was freshly rebuilt and ported, only 3,000 Miles on the entire setup. Block was cleaned and decked, RU numbers were in check. Head was also decked, RU numbers also in check.

I'm starting to think that either a foreign particle trapped in one of the head gasket layers (it was sitting in a box at a shop for quite a while, it could happen), or the fact that I did NOT use copper spray on the gasket might have had something to do with this. The car did overheat once, and got up to 235 Degrees because of an air pocket. This should not caused anything to warp, but I will check the block and head when I have it apart anyway.

So, with this book written, anyone have any other ideas or things I should look for? Should I have really used a copper spray? Is the Mitsu MLS known for this problem? I'm going with a bigger turbo next year, so I don't want to have to go back to a stock gasket. But, if there is a gasket as strong as the Mitsu MLS with better sealing properties, or if anyone knows a good way to get a head gasket to seal better, I'm all ears.

Thanks,
Matt.

 

[hostile]

I would say try to re torque the head studs, if that doesn't fix anything try installing an OEM composite gasket, or get your head and block resurfaced smoother.

 

[99gst_racer]

Well, you could always try a different MLS gasket; something like a Cometic HP. However, there shouldn't be much difference between the Mitsu and the Cometic MLS gaskets. I've seen some guys o-ring the block and use a MLS gasket. They retained a positive seal even with 30+ PSI. Just a thought.....

 

[NOSLO2PT0]

or the fact that I did NOT use copper spray on the gasket might have had something to do with this.

You are getting warmer

Should I have really used a copper spray?

Yup

 

[project_tsi]

I've seen some guys o-ring the block and use a MLS gasket. They retained a positive seal even with 30+ PSI. Just a thought.....

Paul, you haven't seen shit. Please enlighten me on where you saw this.

 

[Coup D E'Tat]

Gasket sealer or not, I'm surprised it isn't sealing with a decked head/block. Mine sealed with a cleaning and copper spray, and my buddies sealed with just a cleaning. No decking, no spray.

But, I suppose something could've got stuck in the layers somewhere, or the head studs weren't torqued properly

Wish I had more to tell ya, but I've never had a problem with it.

 

[Enraged78]

I would say try to re torque the head studs, if that doesn't fix anything try installing an OEM composite gasket, or get your head and block resurfaced smoother.

Thanks for the reply. I already checked the torque on the ARP's. No stretching at all, every one was perfectly within spec. Getting the head resurfaced wouldn't be a big deal, but getting the block resurfaced would involve pulling the motor, something I really don't want to do again. The composite gasket is decent, but I plan on putting down about 400WHP when all is said and done, and I don't think the composite can handle that for very long.

Thanks,
Matt.

 

[Enraged78]

You are getting warmer




Yup

Thanks for the advice. When I rip this apart again, I will check the gasket for foreign material, check the RU of the head and block, check for warpage, and install a new MLS gasket with a copper spray. Oh well, you live, you learn.

Matt.

 

[Enraged78]

Gasket sealer or not, I'm surprised it isn't sealing with a decked head/block. Mine sealed with a cleaning and copper spray, and my buddies sealed with just a cleaning. No decking, no spray.

I'm just as surprised as your are. I've seen many others seal just the way mine was.

But, I suppose something could've got stuck in the layers somewhere, or the head studs weren't torqued properly

Wish I had more to tell ya, but I've never had a problem with it.

The stuck in the layers part I agree with. The head was torqued by a master engine builder with about 40 years of experience, and he's worked on 4G63's before with no issues. I was there when he did it, and the sequence was correct. ARP assembly lube was used, and ARP's instructions were followed to the T. I'm pretty sure the something stuck in one of the head gasket layers is what I'm looking at.

Thanks.
Matt.

 

[99gst_racer]

Paul, you haven't seen shit. Please enlighten me on where you saw this.

Well, there's a few members on this site that are doing it.... Awdboost, Forces32psi
AMS has done it several times --------> click me

And there's some guys on NABR that are doing it too.....
Rich Glorioso is running 35 psi and a 75 shot using the Cometic HP and copper 0-rings. Wes Hess was having best luck with the MLS and copper o-ring combo too.
Kevin Kiggly also ran that combo for a long time, but I believe he is now running just the MLS gasket.

Sometimes on rare occasions, the engine will dump some coolant out of the overflow bottle.

What radiator cap are you using? Many people have this problem until they switch to a 16-19 psi cap.

Should I have really used a copper spray?

On a Mitsu, Yes. If you try a Cometic HP, then you dont have to use the copper spray. The HP's come with a black teflon coating, and Cometic recommends that shouldn't interfer with the contact between the gasket and head/block. Copper stray probably wouldnt hurt the HP, but it probably wouldn't help much either.....

Is the Mitsu MLS known for this problem?

No, the Mitsu MLS is known to be a great performer.

Here's a list of the the best combinations that I have found by searching and reading about other DSMers adventures: (note this list is not in order or anything)
* Felpro composite with a stainless steel o-ringed head
* Mitsu or Cometic MLS with a copper o-ringed block
* Mitsu with copper spray
* Cometic HP on a mirror finish head and block

Gasket sealer or not, I'm surprised it isn't sealing with a decked head/block. Mine sealed with a cleaning and copper spray, and my buddies sealed with just a cleaning. No decking, no spray.

Well, it depends on the quality of the machine job. It is imperative to have the finish on the head and block close to perfect when using a MLS gasket. It seems that with a smooth mirror finish, the MLS gaskets will hold even at 30+ PSI without pushing coolant.

 

[Enraged78]

Well, there's a few members on this site that are doing it....

...


What radiator cap are you using? Many people have this problem until they switch to a 16-19 psi cap.


...


Well, it depends on the quality of the machine job. It is imperative to have the finish on the head and block close to perfect when using a MLS gasket. It seems that with a smooth mirror finish, the MLS gaskets will hold even at 30+ PSI without pushing coolant.

Thanks for the post. When I put the motor together, I switched to the new cap. I'm 100% sure that it's pushing coolant because of the detection of gasses by the analyzer at the filler neck.

I'll use another MLS with copper spray this time around, and make sure there's no foreign particles in the layers. I don't see myself O-ringing the block or head, as everything is all assembled, and I don't plan on pushing 600+ WHP, just 400.

I'll also check on the head and block surfaces, and if there's an issue, I'll have to deal with it then.

Thanks,
Matt.

 

[99gst_racer]

I'll use another MLS with copper spray this time around, and make sure there's no foreign particles in the layers.

Yeah, the MLS HG's are nice, but not all perfect. Nobody has a 100% accurate and efficient product quality control team. Just make sure you inspect the gasket very closely; checking for burs or any other defects.

I don't see myself O-ringing the block or head, as everything is all assembled, and I don't plan on pushing 600+ WHP, just 400.

I agree; you dont need to o-ring with 400 HP goals....
(My above post was just to furthur explain myself to Project_Turd )

Good luck to you.

 

[pimpngear]

ARP assembly lube was used, and ARP's instructions were followed to the T.

Just a quick thought, but as far as I can remember, I don't think the requirements in the instructions were enough torque. I think they call for somewhere around 70 ft lbs. with oil. Not to flame or anything, but i typically slam those studs down to about 75-80 ft lbs. Never had anyone complain about that yet.
-Rob

 

[NOSLO2PT0]

. The head was torqued by a master engine builder with about 40 years of experience, and he's worked on 4G63's before with no issues.

He's a master engine builder, but doesn't know to use copper gasket spray with a metal HG? Sounds more like a master asshat to me!!

 

[Suparata]

Low 11’s running a FP3052 on 110 Octane using a Mitsu MLS with no spray. Around 20K pretty hard miles on the engine.And that is just an example because that particular application can take quite a bit more than that.
No copper spray is needed if the surfaces are flat, smooth and the clamping is correct.
However, 'enough' detonation will compromise any kind of sealing which is not necessarily a bad thing. If something has to let go, the head gasket is preferred over other components.

 

[MNGSX]

the stock composite is much better than the felpro

The stock gasket has made well over 400hp with just ARP's and good surfaces.

you can run copper o-rings with it too.... It has been done. The coolant and oil passages seal alot more consistently on the composite...

Another thing to look into... Kind of extreme but the LS1's have 4 head bolts per hole like a 4g63... some of those guys were lifting with ARP's so they drill and tap for bigger studs and on the twin turbo 6-7 sec tube frame cars they run a dead soft copper gasket with o-rings cut in both the block and deck around the cylinders AND all the passages for oil and coolant...

I agree for most people that the HG should be the fuse...

On the extreme end with a 2.0 crank... stronger than 2.4 due to a shorter lever on the same metalurgy.... and running rods like oliver, manley or pauter heavy weights and duh forged pistons that even the 0-ringed dead soft copper could still be the fuse... Because those rods and pistons probably are'nt going anywhere from just cylinder pressure on a properly tuned engine....

I think your average build up should just run a stock composite and ARP's... Save the difference for things like WB02 that can make a safer more accurate tune on any engine....

 

[Enraged78]

Just a quick thought, but as far as I can remember, I don't think the requirements in the instructions were enough torque. I think they call for somewhere around 70 ft lbs. with oil. Not to flame or anything, but i typically slam those studs down to about 75-80 ft lbs. Never had anyone complain about that yet.
-Rob

No flame retardant suit necessary. Most people don't even know even think about torque requirements. Luckily, we did. We used ARP studs with ARP assembly lubricant. They were toruqed in steps in sequence using ARP's method. With ARP assembly lube, I believe that the torque steps were something like 45, 65, 85. Whatever the instructions listed is what we used.

Thanks for the post.

Matt.

 

[Enraged78]

He's a master engine builder, but doesn't know to use copper gasket spray with a metal HG? Sounds more like a master asshat to me!!

No name calling here, please. If you don't have something to contribute, please do not post.

After speaking to a number of 4G63 engine builders, I am actually finding that many builders are on the fence about using copper spray on the MLS head gasket. The reasoning behind it is because it is a multi-layer gasket, sometimes the copper can get caught between some of the layers and create high spots. This in turn can create sealing issues. I have spoken to three builders besides the one who helped me build my motor that actually refuse to use copper spray on a Mitsu MLS because of this reason.

Matt

 

[Enraged78]

the stock composite is much better than the felpro

I've heard a lot to back this up as well. I'm not running a Felpro now, and don't plan to reguardless of what I do.

The stock gasket has made well over 400hp with just ARP's and good surfaces.

you can run copper o-rings with it too.... It has been done. The coolant and oil passages seal alot more consistently on the composite...
I agree for most people that the HG should be the fuse...

...

On the extreme end with a 2.0 crank... stronger than 2.4 due to a shorter lever on the same metalurgy.... and running rods like oliver, manley or pauter heavy weights and duh forged pistons that even the 0-ringed dead soft copper could still be the fuse... Because those rods and pistons probably are'nt going anywhere from just cylinder pressure on a properly tuned engine....

I think your average build up should just run a stock composite and ARP's... Save the difference for things like WB02 that can make a safer more accurate tune on any engine....

I agree with the O-ringing, but would still have to rip everything apart to do that properly, so I don't really see myself going down that street. However, the stock composite brings up an interesting question. I built this motor with a nice, strong Ross/Eagle combo. In theory, this block should support up to 700 HP. Using the 80% rule, I find that the max HP I should attempt to run is 560. I'm shooting for 500 at the crank, or about 400AWHP. Therefore, I don't thing that the stock composite would be the best fit here. Have you seen otherwise? Asking a stock gasket to do semi-daily 500HP is quite a bit.

Also, one builder mentioned using a straight copper gasket. What are the advantages/disadvantages of this?

Thanks,
Matt.

 

[99gst_racer]

Also, one builder mentioned using a straight copper gasket. What are the advantages/disadvantages of this?

About 99% of my customers that use full copper gaskets (like SCE) can't get them to seal unless they o-ring the block. They are much more difficult to seal as apposed to a MLS. Typically, a copper head gasket and o-ringed block is not really recommended for street use. I would recommend the MLS over the copper gasket anyday.

 

[NOSLO2PT0]

No name calling here, please. If you don't have something to contribute, please do not post.

After speaking to a number of 4G63 engine builders, I am actually finding that many builders are on the fence about using copper spray on the MLS head gasket. The reasoning behind it is because it is a multi-layer gasket, sometimes the copper can get caught between some of the layers and create high spots. This in turn can create sealing issues. I have spoken to three builders besides the one who helped me build my motor that actually refuse to use copper spray on a Mitsu MLS because of this reason.

Matt

Who are these engine builders? Why don't you listen to the people that are putting heads on blocks, then actually putting them into cars and running them down the track? Or would that make too much sense?

Use copper spray with the MLS gasket, and make sure you prep the head/block surface properly before installation.

 

[MNGSX]

I've heard a lot to back this up as well. I'm not running a Felpro now, and don't plan to reguardless of what I do.



I agree with the O-ringing, but would still have to rip everything apart to do that properly, so I don't really see myself going down that street. However, the stock composite brings up an interesting question. I built this motor with a nice, strong Ross/Eagle combo. In theory, this block should support up to 700 HP. Using the 80% rule, I find that the max HP I should attempt to run is 560. I'm shooting for 500 at the crank, or about 400AWHP. Therefore, I don't thing that the stock composite would be the best fit here. Have you seen otherwise? Asking a stock gasket to do semi-daily 500HP is quite a bit.

Also, one builder mentioned using a straight copper gasket. What are the advantages/disadvantages of this?

Thanks,
Matt.

Ask the old guys like BR what gasket they were running in 500+ hp race motors before we had so many gaskets to choose from....

yes others are better but dont under estimate a stock mitsu gasket..

O-ring and copper revisited here..

http://www.dsmtuners.com/forums/showthread.php?p=1048693#post1048693


As for the best gaskets anywhere... SCE > all

http://www.scegaskets.com/products/ics.html

Has an oring in the middle of the gasket at the fire ring.. look at the diagram...

Is a solid copper gasket..

Has the bonded fluid seals around the fluid passageways.

This is what the kind of gasket tech that keeps compound sequential diesels from poping HG's at 90psi boost... Its also what I think you should run..

The ICS titan comes with a 87.3mm bore so its good for 2.4's too... ICS means integrated combustion seal... Therefore its the only SCE that does'nt need a ringed head or deck because its integrated into the gasket...

 

[94Jettameowpsst]

Says no machining or sealants.....im new to this whole aspect of "cars" fill me in here. I know with the mls or a cometic a certain degree of "smoothness" has to be aquired to maintain or reach a proper seal. What exactly is the difference between the machine work between that sce titan and the other 2 gaskets mentioned?

 

[MNGSX]

The straightness and surface finish requirements are identical.. Its just that in the past with the non ICS SCE copper gasket you needed to 0-ring.. The ICS system means that no ringing of the head or deck is needed..

So ICS Titan and any MLS WITH the coolant & oil sealing traces on it like the cometic HP have identical machining and installation prep. Smooth straight surfaces no spray...

The SCE titan needs an o-ring job.. but no spray..

The pro copper needs o-rings and spray.... Its the oldest copper tech...

More FAQ on copper
http://www.headgasket.com/faq.html#q10

IMHO copper does a better job of bridging the gap between heat expansion differences between the aluminum head and the iron block than does the MLS... It also can do it as one solid slab not a sandwich.

PS

Any gasket MLS or Copper that has in laymans terms "the built in rubber lines around passages" should be installed without sealant. Any gasket MLS or copper without them needs sealant.. That is why it is done different ways. Different gaskets have different installation requirements...

 

[94Jettameowpsst]

Its obvious that copper would be more effective in sealing....isnt it more ductle than most metals? I have a LOT to learn about this stuff, id definitely consider myself as a newbie.
Edit: Im leaving this statement here to prove the fact that i dont know what im talking about, i spoke before i read the article, was a help thx
Edit squared: Do any of you happen to have a pic of what an o-ring'd block looks like, im still kinda confused about that?