head gaskets?

[placecrafttim]

I need to replace the head gaskets. 14.1 540! What/Who's to use? I've read a little bit on here and am understanding that the cometic head gaskets need a smoother surface??? Is this true? I also am wondering about the SCE titan head gaskets. Has anybody ran these yet? I'm not sure what I have now but they are orange.

[steelcomp]

I need to replace the head gaskets. 14.1 540! What/Who's to use? I've read a little bit on here and am understanding that the cometic head gaskets need a smoother surface??? Is this true? I also am wondering about the SCE titan head gaskets. Has anybody ran these yet? I'm not sure what I have now but they are orange.
I'm hearing that the FelPro MLS gasket is better than the Cometic, but I don't know personally. I don't know anything about the Titan, but it seems the MLS gaskets are showing superior. Yes, they need a very smooth and flat surface. Most head surfacers have the cutting head slightly tilted so the cuters don't back drag. This is fine with a standard composite gasket, but when you tip a round cutter it's not cutting flat. This can be a problem with the MLS gaskets.

[RCB19]

A new website for Foxy? Nice!

[fc-pilot]

We have had success with the SCE Titan head gaskets. They have worked very well for us thus far. Do you have o-rings in your block and heads? If you do that will limit you as to the head gaskets you can use. If not then you can use the cometics. I just built an engine with the fel-pro MLS gaskets but have yet to run it so I can't really give you any real info about them.
Paul

[steelcomp]

A new website for Foxy? Nice!:D :D

[Warp Speed]

I'm hearing that the FelPro MLS gasket is better than the Cometic, but I don't know personally. I don't know anything about the Titan, but it seems the MLS gaskets are showing superior. Yes, they need a very smooth and flat surface. Most head surfacers have the cutting head slightly tilted so the cuters don't back drag. This is fine with a standard composite gasket, but when you tip a round cutter it's not cutting flat. This can be a problem with the MLS gaskets.
The new Felpro MLS is a little more tollerant of surface finish than the Cometic.
One big thing to keep in mind, is that if you are just replacing the head gaskets, and don't plan on a re-hone, I would stay with something similar in design to what you have. The MLS type gaskets distort the bore allot different (less) than the standard type composite with a "sealing wire" such as the Fel-pro ect... up to a couple of thou depending on block type, stud location, ect.. :idea:
Warp Speed ;)

[IMPATIENT 1]

so on a fresh bored, fresh decked block how much nitrous and compression do you guys think the mls gaskets will handle?

[Warp Speed]

I imagine they will hold a bunch depending on tune-up, deck thickness of both head and block. Cyl head hardness and type and condition of fasteners plays into this also. But I know it will handle it right up to the point of needing o-rings and copper gaskets!
What is that level?? Not sure as I am just getting into the spray for the first time. Hopefully they will handle 950hp + a 300 shot! :idea:
I think tune-up is the key as detonation at high power levels can ruin just about anything in it's path!!!
Warp Speed ;)

[Liberator TJ1984]

so on a fresh bored, fresh decked block how much nitrous and compression do you guys think the mls gaskets will handle?
On .042 thick Cometics ....std.bore 454 on gas ...8:75-1 I've put 22# boost on 'em a few times :D

[Warp Speed]

On .042 thick Cometics ....std.bore 454 on gas ...8:75-1 I've put 22# boost on 'em a few times :D
:eek: :eek: :eek:
They should be fine then Impatient :D
Warp Speed ;)

[Liberator TJ1984]

Pushed the Fel-Pro's out @ 16# before the Cometic's
22# with timing way back and 116 octaine fuel

[IMPATIENT 1]

i'm at 13 to 1 and was gonna spray over 300+hp, studded, half hard blok filled block. i'll be runnin a msd 3stage retard, 1 for starter, 1 for 1st stage of nitrous, 1 for 2nd stage of nitrous:devil: and i'll run 112 when racing, about 105 with 34total when playin on the lake.

[WannabeRacing]

The MLS stuff will hold more than you would think. WAY MORE!
But like stated here, good detonation can kill the sealing on the best stuff with the best machining. Safe tune up means alot.
I know Kenny put 38 pounds of boost to the SCE Titan stuff for something like 35 dyno pulls with no failures. I really like the SCE titan. I run FelPro MLS where I don't run the titans.

[placecrafttim]

Allright so I want to go with Fel Pro mls marine. I can only find a 4.580 bore size for my application. The gaskets I have now are 4.560. Is that going to be a problem? I wouldn't think so But I am no expert. I just want to be sure on this decision. I appreciate the response.

[BrendellaJet]

We have had success with the SCE Titan head gaskets. They have worked very well for us thus far. Do you have o-rings in your block and heads? If you do that will limit you as to the head gaskets you can use. If not then you can use the cometics. I just built an engine with the fel-pro MLS gaskets but have yet to run it so I can't really give you any real info about them.
Paul
Running cometics on mine with an o-ringed block and no probs.

[steelcomp]

On .042 thick Cometics ....std.bore 454 on gas ...8:75-1 I've put 22# boost on 'em a few times :DI've heard of some guys running blown alky with MLS and no o-rings.
The new Felpro MLS is a little more tollerant of surface finish than the Cometic.
One big thing to keep in mind, is that if you are just replacing the head gaskets, and don't plan on a re-hone, I would stay with something similar in design to what you have. The MLS type gaskets distort the bore allot different (less) than the standard type composite with a "sealing wire" such as the Fel-pro ect... up to a couple of thou depending on block type, stud location, ect.. Thanks for that Warp...that's good info and makes complete sense.

[steelcomp]

Allright so I want to go with Fel Pro mls marine. I can only find a 4.580 bore size for my application. The gaskets I have now are 4.560. Is that going to be a problem? I wouldn't think so But I am no expert. I just want to be sure on this decision. I appreciate the response.Should not be a problem. Lay them on the head and make sure everything clears the chambers.

[fc-pilot]

Running cometics on mine with an o-ringed block and no probs.
Thanks for the info. I may just have to give that a whirl one of these days.
Paul

[Liberator TJ1984]

With the Cometics , read the instructions !
They recommend puting a layer of Gasgacinch or Coppercoat between each layer of gasket material !
I used the spray Copper Coat , it was easier to get good coverage on the layers in between than trying to brush the sealant in there ;)
then before installing put a good coat on the outsides too letting it get real tacky -almost dry then bolt down the heads .

[placecrafttim]

So how do you find out what the R/A is on a head? Also if my comp ratio is 14.07 to 1 with a .039 gasket and bore diameter of 4.56 what would it be with a .053 or the .041 with a dia. of 4.580? Or could someone just tell me how to work the ratio formula?

[Outlaw]

http://users.erols.com/srweiss/calccr.htm
try this placecrafttim

[BrendellaJet]

Thanks for the info. I may just have to give that a whirl one of these days.
Paul
Not like I wanted it that way...but the block was already machined and engine builder said it wouldn't be a problem, had run them that way before with no ill effects.

[placecrafttim]

http://users.erols.com/srweiss/calccr.htm
try this placecrafttim
Wow! I didn't realize I could shave a half a point of comp from just a head gasket.
The comp I have now is 14.07 to 1 4.56 gasket bore and .039 compressed.
with fel pro's bore of 4.58 and thickness of .053 compressed 13.5 to one.
Their other gasket yields 13.97 w/ a thickness of .041.
Now I ask this ? How much HP do I lose if any?

[fc-pilot]

You would loose more power having a bigger squish than you will from the compression being lower. Do you need to lower your compression?
Paul

[placecrafttim]

Not really. But I'm having trouble understanding the squish.

[steelcomp]

Not really. But I'm having trouble understanding the squish.Thought someone else might explain this one. Squish is the space or distance between the flat part of the top of the piston at TDC and the surface of the head. It's an important part of combustion chamber effeciency and making good power. In simple terms, as the piston comes up on the compression stroke, those two surfaces come together and force, or "squish" the air fuel mixture out into the open part of the combustion chamber at a high rate of speed. This is important as it helps keep the air and fuel in suspension for a more complete combustion process, which results in more power. Without the proper amount of squish, not only do you lose compression, but you also lose the good mixture and combustion suffers, and in turn, so does power. I think typically, you want no more than about .035-.040" squish. You need to know where your pistons are at TDC in relation to the deck surface of the block. Then it's a simple matter of adding or subtracting that number from the head gasket thickness, and that'll give you your "squish".
Hope that helps.