Author Topic: Cometic head gaskets  (Read 915 times)

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galaxiex

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Cometic head gaskets
« on: September 04, 2021, 09:33:50 AM »
So I'm looking at Cometic MLS head gaskets for my .040 over 428.
4.17 bore.


Cometic has gaskets with 4.165 bore, and then jumps to 4.250.


Should I use the 4.250?


TIA
Every 20 minute job is 1 broken bolt away from becoming a 3 day ordeal.

67xr7cat

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Re: Cometic head gaskets
« Reply #1 on: September 04, 2021, 11:20:10 AM »
You do not want the gasket overhanging into the chamber and the fire ring embossment needs to sit flush against the deck so I'd go with the 4.25" in your case.  Also you need a good finish on the heads and block decks for those gaskets. Know guys will use copper coat and all try seal them, but on new gaskets if the machined surfaces are correct you don't need to do that, just put them on dry.

blykins

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Re: Cometic head gaskets
« Reply #2 on: September 04, 2021, 12:36:35 PM »
You can also look at a Felpro 8554 or a Felpro 1020.  Either will work just fine as well.  Not saying that there is anything wrong with a Cometic, but they are $$$ and are not needed most of the time.
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galaxiex

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Re: Cometic head gaskets
« Reply #3 on: September 04, 2021, 12:51:37 PM »
Cool.  8)


I've used the 1020's in the past and they always worked well.


I'll use them again on this one.
Every 20 minute job is 1 broken bolt away from becoming a 3 day ordeal.