Pic of 2nd Gen Cometic Headgasket
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Pic of 2nd Gen Cometic Headgasket
Here it is, it has 5 layers to it and looks like a very nice piece, so far the install is holding good, after my next re-torque ill lay into it and turn up my boost to 52 psi.
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Fast-Track Enterprise, Inc, very good guy to deal with, he a dealer for Cometic, yes its Dustys truck, I spoke with him about it and he said he is having no issues, ARP has 12mm studs that allow you to go to 150, however they cost a a bunch morel, I was told like $1350.
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Studs Are Between 450 And 500 Bucks, I'd Have To Look. The Gasket Is Like 249. Anyways I Had The Block Decked, I Did Not Cut The Head But Took A Piece Aluminum And 220 Grit Wet Sandpaper And Sanded The Head To Removed High Spots. I Torqued The Head All To 50, Then 5 Lb Increments To 135. Then, I Let The Truck Sit For Two Hrs, And Did 5lb Increments Up To 150.
It Is A P-pumped 24 Valve. I Have Seen 90 Lbs Of Boost, But Have Cranked It Down A Little To About 80-85. It Run 12.22 First Time But Is Over Fueled Or Undertimed. It Has More In It But Will Take Some Tuning. I Like The Gasket, Nice Piece, And So Far Has Gone Above What They Said It Would Do. Hts Is Now A Dealer For Them Too, Since My Truck Was A Gasket Tester. Great Alternative So Far To Fire-ring.
It Is A P-pumped 24 Valve. I Have Seen 90 Lbs Of Boost, But Have Cranked It Down A Little To About 80-85. It Run 12.22 First Time But Is Over Fueled Or Undertimed. It Has More In It But Will Take Some Tuning. I Like The Gasket, Nice Piece, And So Far Has Gone Above What They Said It Would Do. Hts Is Now A Dealer For Them Too, Since My Truck Was A Gasket Tester. Great Alternative So Far To Fire-ring.
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the purpose of the cometic gasket is to eliminate the need for o-rings.
the gasket alone as stated above by dusty is holding up to 90 psi, where as a cummins gasket needs o-rings to hold that much.
this is both of course with studs.
dusty, are you using the standard 12mm studs or did you go for the "super high tech special alloy new age alloy" 12mm studs???
the gasket alone as stated above by dusty is holding up to 90 psi, where as a cummins gasket needs o-rings to hold that much.
this is both of course with studs.
dusty, are you using the standard 12mm studs or did you go for the "super high tech special alloy new age alloy" 12mm studs???
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I suspect that those aren't the std ARPs, as I have heard of them breaking at the 150 lb-ft mark, depending on the lube you use.
I don't think the regular ARP2000 studs can hold 150lb-ft with ARP lube. Maybe with 30wt, but even that would be a stretch (pardon the pun).
jh
I don't think the regular ARP2000 studs can hold 150lb-ft with ARP lube. Maybe with 30wt, but even that would be a stretch (pardon the pun).
jh
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It's not the strength.
It's the ability to maintain seal as the head moves around the block. HGs typically blow because of this lateral shearing. The MLS lets the layers slide across each other and maintain seal.
O-rings and (worse yet) Fire Rings are not a good idea for a street truck IMO because of the stress riser they cause in a head that's known for cracking.
MLS gives more sealing for a given amount of clamping. So you can have 220ksi ARP studs that will hold more than they will with regular gaskets. Or you can go with stronger studs and gain even more sealing. With the 280ksi ARPs, I'd think 70+ psi is no problem unless you have silly high timing.
The other nice thing about Cometic is that they will make gaskets in different thicknesses. So if you want a .020 thicker or .040 thicker gasket or whatever, they can do it. Whether or not they WILL do it depends on how many you're willing to buy, from what I understand.
jh
It's the ability to maintain seal as the head moves around the block. HGs typically blow because of this lateral shearing. The MLS lets the layers slide across each other and maintain seal.
O-rings and (worse yet) Fire Rings are not a good idea for a street truck IMO because of the stress riser they cause in a head that's known for cracking.
MLS gives more sealing for a given amount of clamping. So you can have 220ksi ARP studs that will hold more than they will with regular gaskets. Or you can go with stronger studs and gain even more sealing. With the 280ksi ARPs, I'd think 70+ psi is no problem unless you have silly high timing.
The other nice thing about Cometic is that they will make gaskets in different thicknesses. So if you want a .020 thicker or .040 thicker gasket or whatever, they can do it. Whether or not they WILL do it depends on how many you're willing to buy, from what I understand.
jh
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http://www.cometic.com/domesticauto.aspx
Search under "Dodge" then select "Cummins 5.9"
Looks like they only have 24Vs for now, and it's .060 thick.
Justin
Search under "Dodge" then select "Cummins 5.9"
Looks like they only have 24Vs for now, and it's .060 thick.
Justin