Mitsubishi Metal Head gasket

[Groomz]

If I plan on running JE 9:1 pistons and have the Mitsubishi metal head gasket installed, how much would it reduce my compression ratio by? I would have the block decked so I may not be able to tell exactly. Does anyone have any experience w/ that head gasket and how much boost is safe to run ( ARP bolts would be used )?

 

[snake679]

The amount of boost you can safely run is relative to how well your car is tuned. I have seen cars run 25 psi on sompletely stock setups, but at the same time i have seen metal head gaskets blow at 17 psi.....it is all in the tuning

 

[Groomz]

Yeah, thats sounds about right. Its kind of a vague question, just wanted to see if anyone had any thoughts. Tuning is where its at. Thanx for the post.

 

[1gE.T.]

Ok so Im getting a valve job and need to replace my gasket. What thickness do I need to get. Not taking anything off the head or block just valves.

 

[ecr1055]

the mitsu 4 layer is just as good as comic or hks and is only 60$ from connicelli. You will loose some compression but if you deck the block, it will probably equal out. make sure you use arp studs when doing the gasket. the stock bolts will stretch.

 

[LILGSX96]

Originally posted by ecr1055
the mitsu 4 layer is just as good as comic or hks and is only 60$ from connicelli. You will loose some compression but if you deck the block, it will probably equal out. make sure you use arp studs when doing the gasket. the stock bolts will stretch.

Sorry but the Cometic Head gasket is way better. The Metal Mits. one is good for about 450 hp. Once you are over that then it is time for a Cometic one. The Mits one will begin to push water. I know this for a fact. We went to the dyno @19 psi made 399.8 @ the wheels. We started to push water right after that. Air fuel was at 10.9:1 and timing at 13 degrees EGT at 750 degrees C. So it did not detonate. We ended up with 485whp @ 26-27 psi. And pushing water.
Dont get me wrong the Mits one is a good one just it will push water once you get around te 450 hp mark. As for the compression part if you have decked the head and block and put a mits metal on the car it should take it back to its original compression.

 

[GrocMax]

Originally posted by LILGSX96

Sorry but the Cometic Head gasket is way better. The Metal Mits. one is good for about 450 hp. Once you are over that then it is time for a Cometic one. The Mits one will begin to push water. I know this for a fact. We went to the dyno @19 psi made 399.8 @ the wheels. We started to push water right after that. Air fuel was at 10.9:1 and timing at 13 degrees EGT at 750 degrees C. So it did not detonate. We ended up with 485whp @ 26-27 psi. And pushing water.
Dont get me wrong the Mits one is a good one just it will push water once you get around te 450 hp mark. As for the compression part if you have decked the head and block and put a mits metal on the car it should take it back to its original compression.

Just for a point of referance I know of one car that was assembled almost 2 years ago, lots of miles, lots of passes, and did 600+ HP on the dyno with juice, and has never had any issues at all with the Mitsu MLS. Valve cover has never been off since assembly.

But, that engine was very meticulously assembled.

 

[GRNDSM]

LILGSX96 - did you have your block decked?

I am finding out that all metal gaskets (Mitsu or Cometic) require VERY smooth surface. Many machine shops leave too rough of a surface finish to work well with metal gaskets.

Leon
RR

 

[TimHAwdTsi]

One thing that will help with the leaking due to too rough of a surface when reassembling is the use of a copper spray on the gasket prior to reinstalling it.

 

[nowayout]

for my block I made sure I con't even get .002 through the straight Edge before i asemble my block.

 

[Turboniam]

I have had no trouble with using the Mitsu Metal Head Gasket

 

[TurboTerror]

Like some other person said. The most machine shops will leave too rough of a surface for a metal gasket to adhere properly. The softer composite gaskets will press into the imperfections easier creating a better seal than the metal ones. However if you use a nice coat or two of copper adhesion promoting spray on the gasket and let it all dry before you install them, you will ususally eliminate those problems assuming the surfaces are unusally coarse.

 

[dunkyfried]

ok guys... I am about to have to change my HG , starting to smell antifreeze on startup, and have never done it before.... so If I do go with the Mitsu Mtl gasket, do I have to have the head or deck milled at all... I dont plan on keeping this car for ever. The winter is coming up fast, Wisconsin, and want to have this done in the next w/e or so.

thanks guys and gals

 

[gritsak]

Originally posted by dunkyfried
ok guys... I am about to have to change my HG , starting to smell antifreeze on startup, and have never done it before.... so If I do go with the Mitsu Mtl gasket, do I have to have the head or deck milled at all... I dont plan on keeping this car for ever. The winter is coming up fast, Wisconsin, and want to have this done in the next w/e or so.

thanks guys and gals

you definitely want to have the head resurfaced at least...and check the block...if the car is mostly stock and your not planning on alot of power mods just buy another factory composite HG and you should have better luck getting a good seal

 

[Keaka26]

like the Wiseman said, a metal gasket takes a very nice surface to be able to seal properly. O-ringing heals this a lot.

IMO I would just use stock HG. People have run down into the 10s on STOCK headgasket with ARP headstuds. Good enough for me.