Cometic Head Gaskets and CopperCoat

[JimNolan]

Guys,
    Question:   Do I use copper-coat (spray can) to coat the Cometic .027 head gaskets that I'm using on my Aluminum head/cast iron block 410.

The reason I'm asking is Cometic says they don't need it but I thought I'd ask the guys that put these engines through the wringer. I know on my 406 I used copper coat on the Ford Racing .020 shim gaskets and I've had that engine maxxed out in 2nd gear and it's never showed any problems. Thanks, Jim
   

[Joe-jdc]

I would follow their directions.  I have seen them used and re-used for up to 5 rebuilds without spray coating, and they sealed just fine.  If your block has been decked, it needs to be a fine finish, and the heads need a fine finish for best seal if you milled them.  Joe-JDC.

[JimNolan]

Joe,
   That's just it. The finish. I wouldn't know one finish from the other. The decks have been milled, looks nice. The heads are new Edelbrocks, the finish looks nice. I've read different forums and it all comes down to finish. Am I just stupid for not knowing if a finish is 50 RA or 100 RA.

PS.  I called my machinest and told him I was using the MLS gaskets and wanted to know if the deck surface of the block was OK with MLS gaskets. His answer " Lord, God, yes" . He runs sprint cars and he told me that's the gaskets he used. But, he said to take RTV and put it on your hands and rub the whole gasket with that first. He said it puts a thin layer on the gasket and he'd never had any trouble. He told me the Fel-Pro Racing distributor told him to start doing that with their MLS gaskets. He also told me to torque the gaskets in steps and once the torque had been set to go back and loosen each bolt (in sequence) 1/4 of a turn and then retorque to specs. He said the bolt would turn about an 1/8 rotation more from where it originally was.  What do you guys think. Have you ever heard of this.

[jayb]

I've never heard of that kind of a torque procedure, for Cometic or any other head gaskets.  If they are new, I always use them as is with no coating.  After they are disassembled once, some of the black coating on the gaskets comes off.  At this point I will give them a coat of Copper Coat before their next installation.  But even that may not be necessary,  based on Joe's comments.

The spec they give you for smoothness of the deck finish is not really useful since most of us have no way of measuring it.  Your Edelbrock heads are smooth enough.  If the block looks like that too, you should have no problems.

[JimNolan]

Thanks Jay and Joe,
     I'll do as you say. I figure you've been there on FE's. At least enough to write a book on FE's. Jim

[JimNolan]

It's getting there.

[BruceS]

Jim,
Mighty good looking mill there!  Should do very well in that '57. Those valve covers look like '65-'66 vintage, is that right?  Also, whose headers are those? 
Thanks,

[JimNolan]

BruceS,
    I had those valve covers given to me by a friend that knew I was building a motor. Original 66 GT without a smudge or scar on them. The headers are from Stan Martin, he owns FPA. He's a 57 Ford guy too. He built them for me to go in my 57 Fairlane W/Lakewood and Tremec using the clutch fork. He had a new bender he was trying out. Our "A" arms cause problems with headers. These headers suppose to fit perfectly. I hope so. I'm debating an aluminum water pump or a Napa replacement painted POR natural cast. I know the Napa water pump will be good. Thanks, Jim
   

[Barry_R]

A bit of silicone or copper coat can help the Cometics as far as fluid sealing goes.  At least the older ones were very good at combustion seal but not as good at liquids.  The Fel-Pro MLS (not available for the FE...) have a better factory coating that is almost sticky - the first generation was really sticky and packed in wax paper - and assemble dry.

A retorque is never a bad idea - but can be a PITA on many engines.  My old Fel-Pro buddies had a cold retorque process where they recommended torquing to spec - then walking away for an hour or two - come back, loosen all fasteners and retorque.  It allows the fasteners and gaskets to take a "set" - stretching and relaxing a bit.