Im doing an MLS Cometic right now. How should I prep the mating surfaces? I cant bring it to the machine shop. So I need an alternative method. Fine sandpaper? Scouring pad? thanks again.
Preparing block/head for MLS Gasket.
tw1nturb0
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why cant you bring it to a machine shop? either way if you must then fine emery cloth, and a big block of wood... either way its not going to be as good as machine shop and has a good chance of blowing out.
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1,470 Posts
its nt necessary to have it milled, unless you severlyoverheated the engine. I have done a few headgaskets without any machine work. Just clean up the surfaces without removing any metal, just clean then really good, then drop teh gasket on there and bolt everythign down in the proper torquing sequence. Some people use this spray copper sh*t, i havnt used it once, and i havnt had a singl eissue with any of my engine ive built.
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899 Posts
Use scotch bright pad,and break cleaner.
the before laying the gasket on use the copper headgasket spray and lightly dust the entire gasket.
dont forget to lightly silicone all the oil ports and the front cover part.
the before laying the gasket on use the copper headgasket spray and lightly dust the entire gasket.
dont forget to lightly silicone all the oil ports and the front cover part.
Doluck.. i personally think the cometic is just fine if mated to a perfectly straight and machined surface. I have used and built three engines with Cometic and not once have had a problem. JGYcustoms also states on their site that they use them on 90% of their builds.
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172 Posts
They do work ok.... I may even say good for the money on cars lower than the mid to high 400s.. After that .. wouldnt trush them. They dont fit, nore do the make a bore smaller than 88mm..... They sell you the same FWD gasket with 17 diffrent parts #s, yet they are all the same gasket.. Already been proven.. so dont yell at me. If you call them they just defend themselves and say the FWD and RWD gasket are the same.. but they arnt..
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899 Posts
you have to use it on the front cover part or it will leak oil, and i would go ahead and also use a thin layer on all the oil ports too. i have used the copper spray on 5 cosmetic head gaskets, nun of them had any rubber coating you speak of
obviously no silicone near or around the pistons.
Liquid gasket on the front cover but on the headgasket is a no no. I too have used copper spray on my personal cometic but the new one i purchased, i scraped my nail on it and it definately has a black rubber residue kinda shit on it. Im going to try this one dry for shits and giggles. Copper spray is perfect on paper gaskets as it is used widely in the OEM industry.... EXCEPT Volvo advises against it on OEM gaskets.
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i owned 2 sr20's myself (one stock with cometic, and one fully build with HKS HG) and have assembled 4 others. all 4 with cometic.the one time i didnt use any liquid gasket on the front cover it leaked, (very slowly but it still leaked) luckly that motor was a friend of mine and he didn't care one bit.
(i only use a paper thin layer, very very thin)
on my motor now, i have used some on my front cover even though HKS has their gasket coated with "visable" rubber. i planed to put it on dry BUT somthing told me not to. but i wound up putting the thinest layer of liquid gasket on every oil port.
i have owned my first sr20 in 2003 when i joined. since then i have seen hundreds and builds gone very wrong and a plethora of head gasket problems. i would say 75% of the motors i have seen with no liquid gasket on the front cover leaked out.
Dry as a bone
My last personal SR didnt have any liquid gasket on the H/G but i did use copper spray... never leaked. I guess it all depends on your surface prep. Mine was machined as well as the two screws behind the front of the head assure the seal was as tight as it was going to be on the front cover and 30k miles later it was good till my wiseco pistons shattered due to detonation somehow.
I see you used red liquid gasket... why? I only use grey so it is as invisible as possible.
I see you used red liquid gasket... why? I only use grey so it is as invisible as possible.
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899 Posts
well it makes sense when machined the matting surface will be 100% perfect. so i see how how it works for you.
i always use ultra gray too, i just had 3 tube of the red stuff never used, thought id give it a shot didn't think it would show so much lol...
the gray seems much stronger then red, but the red was alot thinner.
i always use ultra gray too, i just had 3 tube of the red stuff never used, thought id give it a shot didn't think it would show so much lol...
the gray seems much stronger then red, but the red was alot thinner.
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