head gaskets for Big Power Big Boost

[greenjunk]

SO the SCE Copper with stainless rings are the same price as the the Cometic MLS, which are better for 20lbs of boost. What are the trade-offs between one or the other. This motor will not be O-ringed, but from what I've read up on, this is ok.

[FIREBALLMONZA]

Re: head gaskets for Big Power Big Boost

What motor is it??

[dieselgeek]

Re: head gaskets for Big Power Big Boost

SCE coppers, two different FORD 351-based engines I've worked on, had problems sealing up but the Hubers use them on their 4-banger; parish used MLS on his truck and it made your kind of power.

The coppers on the fords would both leak water before they were heat cycled. It was strange, same problem on two separate cars...


anyways that's all I know. Not enough, really.

[Dynoroom]

Re: head gaskets for Big Power Big Boost

I don't use either............. But I've run both......... they do work.......... but so do Fel-Pro.......... at least for me. ;)

Are you running a iron block & alloy heads? If running all aluminum a mls has some pluses. Cometic also offer a gas sealed ring that will work without machining but $$$. The basic SCE Titan does not have the o-ring but does seal water well. Their wire embedded o-ring gasket has had a tendency to "lift" the head and allow coolant to seep/leak depending on if you are running a electric or belt driven water pump.

20lbs. is not a lot of boost.

[squirrel]

Re: head gaskets for Big Power Big Boost

20lbs. is not a lot of boost.

YOU can say that

[revolutionary]

Re: head gaskets for Big Power Big Boost

On small block stuff running 15-18 psi boost the SCE Titans were ok but as soon as we started bumping over 20 psi they were junk. We run Cometic and Felpro MLS on about everything now with no problems as long as the block and head are flat and the head hasn't annealed. That is on small block 427/434's with 22-25 psi boost making ~1500 at the wheels. With 20 psi and 1200rwhp it is not even close to an issue.

[min301]

Re: head gaskets for Big Power Big Boost

Fel-Pro or Cometic MLS would be my choice.

[dieselgeek]

Re: head gaskets for Big Power Big Boost

20lbs. is not a lot of boost.

YOU can say that

nobody can say that, because "boost" is not very relevant.

He wants to run his 20psi with a relatively large turbo (efficient), and something above 10:1 compression. He's talking about more serious cylinder pressure than the typical "20 psi" crowd.


But a good point that Mike makes, that I agree with: if the tune is on, Fel Pros will probably do just fine. On the Mitsu 4G63 engines (I do a lot of those, 40+psi from a GT35R usually) it was long rumored on the internet forums that you MUST get rid of the stock headgasket for anything more than "18psi" (whatever that means), but we found that if you stay away from knock, the stockers will hold 900+ hp reliably.

[CTX-SLPR]

Re: head gaskets for Big Power Big Boost

20lbs. is not a lot of boost.

YOU can say that

nobody can say that, because "boost" is not very relevant.

He wants to run his 20psi with a relatively large turbo (efficient), and something above 10:1 compression. He's talking about more serious cylinder pressure than the typical "20 psi" crowd.


But a good point that Mike makes, that I agree with: if the tune is on, Fel Pros will probably do just fine. On the Mitsu 4G63 engines (I do a lot of those, 40+psi from a GT35R usually) it was long rumored on the internet forums that you MUST get rid of the stock headgasket for anything more than "18psi" (whatever that means), but we found that if you stay away from knock, the stockers will hold 900+ hp reliably.

I have cheap Fel-Pro gaskets on my Turbo6 for this very reason. If the tune gets off, it'll blow the gasket instead of wrecking one of my expensive custom pistons.

[A/Fuel]

Re: head gaskets for Big Power Big Boost

I would think you would stand a chance of wrecking the head if the gasket fails.
What about using better studs and more torque?

[IRONHEAD]

Re: head gaskets for Big Power Big Boost

I would think you would stand a chance of wrecking the head if the gasket fails.
What about using better studs and more torque?

not only that hyd a piston/rod

[min301]

Re: head gaskets for Big Power Big Boost

I would think you would stand a chance of wrecking the head if the gasket fails.
What about using better studs and more torque?

not only that hyd a piston/rod

What the hell does that mean, Mark???

[CTX-SLPR]

Re: head gaskets for Big Power Big Boost

It's got ARP studs and the recomended torque. Heads are iron on an iron block.

Anyway, the Cometics on Buick V6's are known to seep between layers, don't know if it's a problem universally. No one I know with a Turbo6 uses a copper gasket, most use the Fel-Pro's with fire rings or Cometics. Stock Buick heads have 4bolts per cylinder, Stage blocks have 6.

[Dynoroom]

Re: head gaskets for Big Power Big Boost

20lbs. is not a lot of boost.

YOU can say that

nobody can say that, because "boost" is not very relevant.
He wants to run his 20psi with a relatively large turbo (efficient), and something above 10:1 compression. He's talking about more serious cylinder pressure than the typical "20 psi" crowd.


But a good point that Mike makes, that I agree with: if the tune is on, Fel Pros will probably do just fine. On the Mitsu 4G63 engines (I do a lot of those, 40+psi from a GT35R usually) it was long rumored on the internet forums that you MUST get rid of the stock headgasket for anything more than "18psi" (whatever that means), but we found that if you stay away from knock, the stockers will hold 900+ hp reliably.

Scott, your statement about boost pressure is correct but let's get real. in the application we're talking about here it relative to the question he asked. 20 psi with a t-3 type turbo is the same 20 psi with a tv-91 type. The air flow at that pressure ratio will be very different so the amount of power able to be produced is not the same for this example of turbos.

Now, as far as head gaskets go, I've used Fel-Pro #1003 on 4.00" bore stuff making well over 1200 hp crank. I've used their same construction gaskets on 4.125" bore stuff making over 1400 hp & on big blocks making ~2000 hp. All of these turbo engines run ~10.0:1 (a couple almost 11.0:1) on gasoline.
Yes you can use other gaskets, they will work. I'm just pointing out you can get these Fel-Pro's at any speed shop any day of the week any where in the country.....

And yes, I can say that! :D

[A/Fuel]

Re: head gaskets for Big Power Big Boost

A nitro engine puts a lot of stress on a head gasket too, even if it's not supercharged. The things we do to get it to seal might seem unorthodox to some of you, but sometimes you gotta do what you gotta do. Water leaking is not an issue, but other than that, alot of things might be the same. O-ringed heads and copper gaskest are a must, and usually the thicker the gasket the better they seal, up to a point. I'm talking about using a .050-.080 though, and then we get rods to match. In my experience ones less than a .040 will burn and when we get over a .090 we start running into problems with intakes and pushrods. Some of the best things I've seen are going to the HP1-11 9/16" tooled steel studs and bigger dowel pins. Then I snug them all up with an impact in rows, from the middle out, not in circles. Then the inside studs get torqued to 65lbs...all in a row. Then the top row to 175lbs, then the bottom row to 155lbs. (yes, it's a work out) Coat all the studs with "peanut butter" the stuff you can get from a Detroit Diesel shop. We use the big washers too. 90 percent of the failures we deal with go into the intake valley and nip at the pushrods (a tip i figured out: I'll pull a pushrod out and see if its burnt before I get a leak down tester out)
Usually the gasket won't fail unless the head comes up or starts bouncing.