which head gasket

[90rslaser]

so heres my thing. i have a fully built head, completely stock bottom end with an original 90k miles on it. i already have arp studs, and all the supporting mods for my hx35 which is going to be running 35-40 lbs of boost. which head gasket can i use without having to pull the engine and resurface the block? ive already used a rolloc wheel to clean the block. can i use a oem mitsu metal h/g, or a oem mitsu felt? both are going to be coming from street tuned motorsports. thanks guys

 

[laser_92]

If you have your block exposed now, I'd check your block with a straightedge and feeler gauge to make sure it's true. If it's good then go with the MLS. They need a nice clean/perfect surface to adhere to properly. If your at all unsure about it, then I'd go with the OEM felt. I've seen 30psi anyway on a stock (new) bottom end with OEM felt and standard ARP's. Anything more and it started to push a little coolant. I've since gone with O-rings in the block, L19's, and an OEM felt. Problem solved

I'd say 30psi on an HX35, OEM felt, and your arp's and you'll be satisfied. Plus their so dang cheap to replace if need be at $35ea. vs $100+.

 

[welfle18]

I would personally say that if you plan on pushing the to 35-40 lbs then you best be ready to build your bottom end cause I doubt that it take that much abuse for long. I would get the MLS gasket also if you are going to running that much boost because you will be pushing coolant and oil after to long. I say 30psi and below are suitable for the composite gasket anything other than that you will be testing your luck, which you will already be doing with the stock bottom end.

 

[BogusSVO]

ive already used a rolloc wheel to clean the block. can i use a oem mitsu metal h/g, or a oem mitsu felt?

with you saying that... you now have to use a composite gasket.

the use of a rol loc will round the edges of the block and also "wave" the deck surface

 

[90rslaser]

thanks bogus svo, i actually came across one of your posts about using the hand held sander thingy(non powered) and was thinking about trying that. straight edge looked good on it(cant remember what the feeler gauge said but it wasnt very much at all). this is NOT a daily driver, weekend only car. so im not going to be boosting it all the time. i guess i will just try the felt gasket with copper spray and give it a shot. thanks guys. is composite and felt gasket the same thing, or what am i missing

 

[welfle18]

Yeah they are the same thing. I am going to run an OEM composite headgasket with my build.

 

[90rslaser]

you guys think copper spray on the head gasket will help it at all with sealing a little bit better?

 

[my98gsx]

I ALWAYS copper spray mine.

 

[2g 6 bolt swap]

If you already have the head off. You might as well go and spend a little more money on a head gasket if your planing on running that high of boost. MLS metal head gasket is a good way to go for the price. Better safe then sorry so you dont have to go back and do it again. Either way, yes copper spray is always a good idea.

 

[kahl23]

Cheapest and easiest: Use an OEM composite gasket, many people have gone very fast on them and they tend to be easier to seal than MLS gaskets. Downside is that they are more fragile and more prone to damage from knock, however this also can let them act like a sort of fuse on the engine, blowing the HG before you get into more trouble.

Midrange: Get the mitsu MLS gasket. Used these for a while, had some issues getting them to seal, but all in all a solid gasket. We never used copper spray as we were told not to, but ymmv. You need to get your head resurfaced, and though I am unfamiliar with a roloc it sounds like you may need to get the block checked out too. Surfaces should be 40RA or better.

More Expensive: Fel Pro Permatorque MLS Head Gasket-DSM : JNZ Tuning Best gasket Ive heard of, but you pay for it. Same rules for surfaces apply as above.

Good luck!

 

[codeofdastreets]

Original piston rings?? You should do a compression test to make sure compression still good.. nd I'm not sure if the mitsu felt will hold at boost that high.. You should just tale out the block nd get it resurfaced wit a mls gasket

 

[90rslaser]

yeah i think im going to just use the oem comp gasket. it should hold for a weekend warrior until my actual build is done. then i can tear into this sucker and do it all over again with a mild built bottom end and use it as a dd. btw, head is fresh out of the machine shop so i dont have to worry about that. if all and all fails, its not like i spent thousands of dollars on the car and motor. got the head done for 650. that includes machine work, porting/polishing, bowl mixing and assembly by a very good friend that owns a machine shop. of course i had to pay for all the valve train components though, but that wasnt too bad either. i will give the composite gasket with copper spray and post results when all is said and done. thank you for all the responses guys.

 

[2g 6 bolt swap]

Sounds good man. Either way your car will run like it should. Good luck.

 

[90rslaser]

thanks guys i appreciate the help. and good non shit talking help .

 

[BogusSVO]

How was the head surfaced?

 

[black_gst]

make sure to check the head and make sure its flat and do not run any type of metal HG unless you have had the block decked. i am puching coolant on my 2nd HG 1st a cometic pushed coolant and now a mitsu metal HG with copper spray, and this is afer the machine shop swore the block didnt to need to be decked even after i told them the surface requirments for my HG

ima run a Felpro

ha

 

[90rslaser]

it was cbn resurfaced. no belt sander used on my head! .

 

[BogusSVO]

it was cbn resurfaced. no belt sander used on my head! .

GREAT!! thats what I was checking for!

 

[90rslaser]

yep! and youre the reason(bogussvo) i made sure the machine shop did it that way. i read every freakin post of yours, and machine work shit finally makes sense. but either way, i swallowed my pride and took the engine out. gonna send it to the shop here in the next few days and have the block and everything resurfaced. but im still only going to use a felt gasket cause i would prefer the head gasket to blow before the engine . btw, do you think a set of wiseco pistons on stock 1g rods would be safe enough for around 550 awhp at about 35lbs of boost?

 

[talondave]

yep! and youre the reason(bogussvo) i made sure the machine shop did it that way. i read every freakin post of yours, and machine work shit finally makes sense. but either way, i swallowed my pride and took the engine out. gonna send it to the shop here in the next few days and have the block and everything resurfaced. but im still only going to use a felt gasket cause i would prefer the head gasket to blow before the engine . btw, do you think a set of wiseco pistons on stock 1g rods would be safe enough for around 550 awhp at about 35lbs of boost?

I would at least put arp's in the rods, the stock studs are the weakest point in the 1g rods.

 

[90rslaser]

yep planned on having the machine shop do that. and does anyone know of a reallygood bse kit, that comes with EVERYTHING?

 

[BogusSVO]

If your going to have ARP installed into the rods and have the rods resized, you may as well look into jst getting a set of Hbeam rods, you may not be that far off from a set (even the knockoff eagles) and have the whole deal balanced.



BTW, people like you are the reason I do the how to posts, so they can learn and understand better what they need to have done and why.

I am glad to help!

 

[90rslaser]

you may not be that far off from a set (even the knockoff eagles) and have the whole deal balanced.

what are these knock offs you speak of? . will they SAFELY, hold 500-600hp?

 

[BogusSVO]

check ebay.... compaire the specs to the eagle rods, both ate 4340 chrome moly with arp's

MITSUBISHI 4G63 GEN II ECLIPSE H BEAM ROD 5.905 & 5.787 : eBay Motors (item 400104123149 end time Mar-19-10 14:33:26 PDT)