Max boost on a composite gasket

[rr06rs]

I'm just curious what the max boost level is that people have safely seen? I'm replacing it and throwing in ARP's but the motor is staying in the car so the block won't be resurfaced. For the record, the gasket isn't blown, it's just a high mileage engine with some seapage and I'm just doing the basic maintenance on it while I put it back together so I already know it's not warped.

Also, if I were to have the head alone decked, would it be possible to use a MLS maybe with some copper spray on just the block side or would it be recommended to still use a composite? It's going to be a stock 6 bolt running about 35lb's max on a 6057.

 

[gofer]

It seems like your going into this a bit wrong, basing the amount of boost you run on your headgasket and headstuds isn't the way to do things. The amount of boost you run using that turbo depends on your fuel setup, tune, and engine internals. The ARP headstuds and composite hg will hold the head down on the block running 35psi but that doesn't mean you can run that much boost.

I don't recommend running a MLS hg if your just pulling the head, you'll be better off going with the composite hg, copper spray it doing the install too. I run 30psi on my stock 7-bolt bottom end with a Mitsu composite hg and ARP headstuds and the engines been just fine for nearly a year.

Update your profile modifications list.

 

[9!'clipseDOHC]

Like Gofer said, there is no magic amount of boost or horsepower that a composite head gasket will hold. It all depends on your tune. With what you are saying about your setup, there is no way I would use an MLS gasket. I would use an OEM with ARP studs (which is what I am personally using).

Copper spray is a whole different issue, some people swear by it, others curse it. I've never used it or needed to use it. I see it like putting hairspray on your intercooler couplers. If it's going to blow a t-bolt clamp off, I don't think the hairspray is going to help. Same with the copper spray, if your lifting your APR studs and blowing your gasket, I don't think the spray is going to help. That is just the way that I look at it.

 

[XiKeiyaZI]

ARPs and a Composite, as stated twice will handle pretty much whatever you can throw at it. However, I believe that if you properly tune that vehicle then by 24PSI you'll be dailing it back. By the fact that you've asked your original question by this, I don't think you completely understand what a difference a few PSI really is, nor that 20PSI via a single turbo is equal to 20PSI from a different turbo. Not to mention what a tune can do with 20PSI versus an Untuned 20PSI.

Do some research before you turn up the boost.

 

[ALBurgundy]

I run 30psi on my stock 7-bolt bottom end with a Mitsu composite hg and ARP headstuds and the engines been just fine for nearly a year.

Wow, I didnt know the composite gasket could handle that much.

 

[9!'clipseDOHC]

Wow, I didnt know the composite gasket could handle that much.

Seems to be a pretty common misconception.

 

[Tanro]

As it has been said. ARPs and a composite can be used to hold a lot of boost/hp.

ARPs and a Name Brand composite are gonna be a great option if your not pulling the drivetrain.

MLS Requires a head and block resurface and can still be a pita to install properly.

I know its been said, but just want to reassure you. I am running 18 psi on ARPs/Composite. Cometic/OEM/Fel Pro is the way to go. I think there is one other brand that is rated for like 450 whp.

 

[DSMReviver]

Yeah believe it or not but the OEM head gaskets are awesome. They have been proven in action with 500-600hp cars.

The only thing when it fail is not the gaskets fault. its the factory head studs. they began to stretch and cause blow coolents.. etc. Thats is why its so important to use it with ARP studs.

 

[Talipse96]

Aren't the OEM gaskets and FEL-PRO gaskets the same thing but with a different sticker on them? Sticker being the name brand that is on the gasket its self that helps it bond to the block and head.

 

[nek]

Fel pro gaskets used to be really crappy back in the day but the have come to make a really great product now and they have been proven. On a side note, is it possible to get away without machining your head on a composite gasket?

 

[Talipse96]

I am very unsure to what I can do with the composit gasket. My goal is 400awhp. I have ARP's. I also have a resurfaced head and block. I just don't know what Ra rating they used to resurface my parts, so I'm worried if I went MLS I'll push coolant.

 

[DSMReviver]

Fel pro gaskets used to be really crappy back in the day but the have come to make a really great product now and they have been proven. On a side note, is it possible to get away without machining your head on a composite gasket?

Long as its straight and flat and there is no high spots(head and the block). I know on metal multilayer gaskets it need 50RA or better. I think it will be ok on the fel pro gaskets.

I am very unsure to what I can do with the composit gasket. My goal is 400awhp. I have ARP's. I also have a resurfaced head and block. I just don't know what Ra rating they used to resurface my parts, so I'm worried if I went MLS I'll push coolant.

Yeah i had my head resurface without knowing a year ago of what the RA's are. But i did use copper spray and sprayed both sides. As of right now its holding fine but i haven't been running boost more that factory so i don't really know yet. if i were you, i would just go for it. i would run it like it is and see how far you can take it. I think it will be fine...

 

[Talipse96]

I think the 16G I'm running righ now the FEL-PRO will be fine. It's when I get my buddies Holset that I think I might have issues. I think I need to contact the machine shop and ask a couple questions. I already know to check for flatness.

 

[MY1GDSM]

On a side note, is it possible to get away without machining your head on a composite gasket?

Not if it's out of Spec...

 

[DSMReviver]

I think the 16G I'm running righ now the FEL-PRO will be fine. It's when I get my buddies Holset that I think I might have issues. I think I need to contact the machine shop and ask a couple questions. I already know to check for flatness.

if the machine shop did their job right and know what they are doin, the head and block they machine will be ok. Yeah, i would definitely call them up and demand answers on what the heck they did haha.

 

[99gst_racer]

Aren't the OEM gaskets and FEL-PRO gaskets the same thing but with a different sticker on them? Sticker being the name brand that is on the gasket its self that helps it bond to the block and head.

They're similar, but not identical. The Mitsu composite HG has a wider firing ring and works much better with an 0-ring. They're both great gaskets and I've had nothing but success with each, but I do prefer the Mitsu composite.





<------- I made this power running 47 PSI on a Mitsu composite head gasket. It's a very capable gasket.

 

[ALBurgundy]

The Mitsu composite HG has a wider firing ring and works much better with an 0-ring.

oring? is this something seprate from the gasket itself?

 

[99gst_racer]

oring? is this something seprate from the gasket itself?

I was referring to a stainless steel or copper o-ring inserted into the block or head surface. Helps immensley with HG sealing with high boost/HP.

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[XiKeiyaZI]

That's the first I've seen of an O-ring like that. Is it machined into the block or what?

 

[ALBurgundy]

I was referring to a stainless steel or copper o-ring inserted into the block or head surface. Helps immensley with HG sealing with high boost/HP.

where can i get more info on this.
where to get them and how to properly install/measure for what size to use.

I can see how this paired with the composite HG would be the way to go.

 

[99gst_racer]

That's the first I've seen of an O-ring like that. Is it machined into the block or what?

where can i get more info on this.
where to get them and how to properly install/measure for what size to use.

I can see how this paired with the composite HG would be the way to go.

Basically, you cut a groove into the deck and insert a wire around each bore. The traditional wire diameter for stainless steel is .041". The depth of the cut depends on how far you want the wire to protrude from the deck surface. And the amount of protrusion depends on the gasket being used. Upon assembly, the wire will press into the firing ring of the HG and assist it in sealing under extreme cylinder pressures.

More info here: http://www.dsmtuners.com/forums/cyl...t-o-ringed-merged-2-7-o-ring-oring-block.html

I'm a big fan because it works very well, and allows me to use one of the cheapest head gaskets available. And the Mitsu composite gasket is great for the use of o-rings.

 

[turbo tim1]

I blew my stock head gasket on my car, at the time I was running a 60 trim turbo at 25 psi and I just installed 272 cams at the time of the failure. I blew my head gasket and white cloud followed me till I stopped. At the time I thought I blew the engine so I figured if its coming out any way I mind as well drive it home so I did. Upon taking it apart I found The gasket blew out by the timing gears, So I had the head resurfaced put a gasket on and compression checked the engine, the compression check was good. (I don't remember the numbers but they were good enough to be acceptable) I upgraded to arp head studs and drove it for a year and a half till my forged engine was ready for drop in. I didn't have an issue with the gasket after I upgraded the studs.

I would stay away from copper head gaskets, when I built my engine I had the head and block surfaced to RA 80 and I had problems with combustion pressure leaking into the cooling system when boost was above 25 psi. I replaced the gasket with another copper and the same thing happened so I Replaced it again with a cometic mls and had no issue's.

 

[XiKeiyaZI]

Basically, you cut a groove into the deck and insert a wire around each bore. The traditional wire diameter for stainless steel is .041". The depth of the cut depends on how far you want the wire to protrude from the deck surface. And the amount of protrusion depends on the gasket being used. Upon assembly, the wire will press into the firing ring of the HG and assist it in sealing under extreme cylinder pressures.

More info here: http://www.dsmtuners.com/forums/cyl...t-o-ringed-merged-2-7-o-ring-oring-block.html

I'm a big fan because it works very well, and allows me to use one of the cheapest head gaskets available. And the Mitsu composite gasket is great for the use of o-rings.

This, is genius use of simplicity at it's best.

 

[MY1GDSM]

Kinda getting OT But I'd have to agree on the copper gaskets, They seem to be really hit or miss I had similar problems with them... .Before running a Composite.

 

[ALBurgundy]

I learned alot of good info out of this.
Last question.

Can I bring the head to a machine shop with the composite gasket I plan to use and have them oring the head and not the block.
This would be easier since I plan on using the stock bottom end without tearing it down.