what head gasket should i use?

[Bojangles465]

I have a 1990 plymouth laser rs turbo, with an evo III big 16g turbo, and i am currently running right around 7-10 psi. My head gasket has blown in between the cylinders and is pushing coolant and overheating, so since i am going to have to lift the head anyways, i am thinking about just biting the bullet and getting ARP head studs, and a MLS HG. my question to you is, what head gasket, and stud combo should i use? i may possibly be getting a holset HX-40 turbo to put on it, so what would be good to use?

 

[gofer]

ARP headstuds and the OE composite head gasket.

I don't recommend running a MLS head gasket unless you resurface both the block and head. Even then, to get a MLS gasket to seal properly, you've got to get it resurfaced to a very low Ra finish. Most reputable engine builders do a 50Ra finish or lower on engines that will use a MLS head gasket.

 

[BogusSVO]

If you popped a HG at 7-10 psi on a 16g you have other issues. Either your tune is off or either the block surface is np good or the head surface is no good.

Just slamming a MLS HG on with some ARP will mask what is at fault, until another part fails.

 

[phr0st]

ARP headstuds and the OE composite head gasket.

I don't recommend running a MLS head gasket unless you resurface both the block and head. Even then, to get a MLS gasket to seal properly, you've got to get it resurfaced to a very low Ra finish. Most reputable engine builders do a 50Ra finish or lower on engines that will use a MLS head gasket.

This. Plus the oem composite gasket has been proven to still handle a decent amount of power when torqued properly. Also notice he said OE gasket, not a gasket that "meets or exceeds oem specs" if you get my drift.

 

[Bojangles465]

If you popped a HG at 7-10 psi on a 16g you have other issues. Either your tune is off or either the block surface is np good or the head surface is no good.

Just slamming a MLS HG on with some ARP will mask what is at fault, until another part fails.

im thinking that the previous owner just didnt torque the head properly and that caused the head gasket to fail, because every nut and bolt the guy touched seems loose, including the head bolts, and so far as a tune goes, i have no tune. I am pretty much all stock, with the exception of a 2g maf that i swapped on it, and my 16g and my ebay tubular exaust manifold, and act 2100 clutch. im still running the stock blue top injectors and everything.

ARP headstuds and the OE composite head gasket.

I don't recommend running a MLS head gasket unless you resurface both the block and head. Even then, to get a MLS gasket to seal properly, you've got to get it resurfaced to a very low Ra finish. Most reputable engine builders do a 50Ra finish or lower on engines that will use a MLS head gasket.

im having my head taken to the machine shop, so the head shouldnt be a problem, but with the block, is this really nessisary? i really dont want to take out the entire engine, how can i check the surface of the block to see if it is warped? also, so youre saying i have to have the gasket resurfaced?? why isnt it a perfect finish from the factory?

 

[BogusSVO]

No, the block surfaced is distorted, The HG will be just fine out of the package.

You are no where close to needing a MLS HG. Stay composite.

With a composite, you do not have to be as concerned with the head and block surface as you have to be with a MLS

Once you get over 500 hp or a turbo that is going 30+psi Then you can worry about a MLS HG.

http://www.dsmtuners.com/forums/cyl...-deck-4g63-cast-iron-block.html#post152790451

 

[Bojangles465]

No, the block surfaced is distorted, The HG will be just fine out of the package.

You are no where close to needing a MLS HG. Stay composite.

With a composite, you do not have to be as concerned with the head and block surface as you have to be with a MLS

Once you get over 500 hp or a turbo that is going 30+psi Then you can worry about a MLS HG.

http://www.dsmtuners.com/forums/cyl...-deck-4g63-cast-iron-block.html#post152790451

i actually just read that thread that you linked to a second ago, but the reason i am wanting to go mls is because i soon may be running around 30 psi on a holset hx-40, but now for another question...

this is the method I recomend IF the block has not been decked and your doing a HG swap in car.
I Recomend this way of cleaning the block for ANY head gasket!!
I do not like "Rol-Loc" for cleaning of head gasket surfaces, I have had to deck blocks beacuse of them, if not used properly, they will "wave" the block block surface.

your are NOT trying to sand the block shiney, but just clean the surface.
also proper cleaning of the cylinder bores of all grit is needed BEFORE applying the copper coat.

the above is a quote from your head surfacing thread. so from wha i gather from that quote, if i sand the block surface and clean it with brake cleaner, it should be good enough , given that the surface is straight? sorry if im not understanding, but that is after all why this is in the newbie section.

 

[TSIfreek]

Do a composite HG with the ARP studs torqued to 90 FT lbs and you will be good to go. You dont want to mess around with a MLS right now as it wont seal.

For a MLS to seal it needs to be a perfect finish and you wont get that at home.

 

[Bojangles465]

im going to lift the head and see what i have to work with, because according to the PO, the engine had been rebuilt and has about 15000 miles on it, so maybe if the surface is good, i may be able to use a mls gasket. until i remove the head, i have no idea what the condition of the block is in. But no matter what i end up doing with the gasket, what brand is the best gasket for the price? felpro? hks? cometic?

 

[TSIfreek]

im going to lift the head and see what i have to work with, because according to the PO, the engine had been rebuilt and has about 15000 miles on it, so maybe if the surface is good, i may be able to use a mls gasket. until i remove the head, i have no idea what the condition of the block is in. But no matter what i end up doing with the gasket, what brand is the best gasket for the price? felpro? hks? cometic?

Any composite gasket will work fine felpro or OEM. Your motor wont see any power diffrence from the MLS or the composite.

 

[Bojangles465]

Any composite gasket will work fine felpro or OEM. Your motor wont see any power diffrence from the MLS or the composite.

i know that the head gasket wont make any power differences, but i am wanting a gasket that will last a good long time, and also be able to hold high boost. i guess since im eventually wanting to get forged internals, i might as well get a composite, and when i get the rods, crank, and pistons im going to use, lift the block out, and have it gone through and then go MLS. thanks for the help!

 

[evobullit2017]

that is what i would do for now make sure to use copper spray on the gasket

 

[Tiki2777]

Unless you plan on machining both the head and the block, do not use an MLS. (you've been warned...) IMO, stick with a composite, it's been proven to take the abuse with good head studs.

 

[Bojangles465]

Unless you plan on machining both the head and the block, do not use an MLS. (you've been warned...) IMO, stick with a composite, it's been proven to take the abuse with good head studs.

i went ahead and ordered some arps and a mls cometic for 200$ and im going to have my head and block surfaced. i like to do prevenative maintanance

 

[BogusSVO]

You do understand the engine will have to be fully disassembled. Crank, rods & Pistons need to be out.

The most accurate way to have the block decked is to set up off the main journals of the block.

So add rod and main bearings, gasket set and rings. So if you go this far you may as well have the block bored and get a set of over sized pistons.

So you may as well plan on a rebuild.

 

[harrison_gst]

felpro unless you get the head machined

 

[Bojangles465]

You do understand the engine will have to be fully disassembled. Crank, rods & Pistons need to be out.

The most accurate way to have the block decked is to set up off the main journals of the block.

So add rod and main bearings, gasket set and rings. So if you go this far you may as well have the block bored and get a set of over sized pistons.

So you may as well plan on a rebuild.

hmm im just going to take the head off to be machined and ill decide what to do with the gasket after i see the condition of the block. i read that the cometic black series has a coating on it that makes it less needed to have a mirror finish on the block, so ill figure something out, if i dont use it on this motor, the gasket will sure be used on something else down the road.

 

[TSIfreek]

You do understand the engine will have to be fully disassembled. Crank, rods & Pistons need to be out.

The most accurate way to have the block decked is to set up off the main journals of the block.

So add rod and main bearings, gasket set and rings. So if you go this far you may as well have the block bored and get a set of over sized pistons.

So you may as well plan on a rebuild.

Thank you dale

 

[TimF]

go and get a metal ruler and a feeler gauge, and check the clearances on your deck. I just went through the whole pull the block/ head apart and mill it all down, and i am still running a composite HG. I am also planning om running a holset. I thought about going MLS but figured what was the point of spending 200+ when my current HG is said to hold more HP than what I am going to make.

 

[TSIfreek]

go and get a metal ruler and a feeler gauge, and check the clearances on your deck. I just went through the whole pull the block/ head apart and mill it all down, and i am still running a composite HG. I am also planning om running a holset. I thought about going MLS but figured what was the point of spending 200+ when my current HG is said to hold more HP than what I am going to make.

This is getting more and more common

 

[supersilverspeed]

thats crazy, deffinetely take the head and block to machine shop and get specs. something is not right. hx-40s make good power. dont cheat yourself, get yourself a set of L-19s and a permatorque,

 

[Bojangles465]

ill check the deck clearances as soon as i get the head taken off