OEM Head gakset thickness

[15GaurdGT]

Anyone know what the thickness is on an OEM head gasket? Motor from JPC has .045 min gasket written on it. I have new stock gaskets but I can't find the thickness.

Thanks.

Sponsored

 

[Elp_jc]

I was under the understanding there are O-ring type gaskets now, but maybe just Gen3s? Or are they?

 

[15GaurdGT]

Its .039 if anyone ever needs to know.

 

[engineermike]

I know someone who measured them and reported .040 on a used set, not compressed. I’ve been trying to figure out the compressed thickness myself. When I run the numbers using actual deck height and piston dome and chamber volumes reported by Mahle, the only way I can get to ford’s advertised compression ratio is with .030.

 

[15GaurdGT]

Its very possible the number they gave me is uncompressed.

 

[GregO]

Advertised head gasket thickness is the compressed thickness.

 

[GregO]

When I run the numbers using actual deck height and piston dome and chamber volumes reported by Mahle, the only way I can get to ford’s advertised compression ratio is with .030.

Just thinking out loud;
It's possible Mahle's numbers are skewed a bit ?
Wrist pin height and crevice volume come to mind.

 

[engineermike]

Just thinking out loud;
It's possible Mahle's numbers are skewed a bit ?
Wrist pin height and crevice volume come to mind.

I don’t know, but what I’m going off of is this:
Bore: 3.66
Stroke 3.65
Gasket bore: 3.7
Compressed gasket: .040
Chamber: 59 (mahle catalog page 16)
Dome: 8.4 (mahle catalog page 16)
Deck height: 0.015 (measured)

CR= 11.45. Ford says 12/1. Substitute in .030 and it yields 11.76/1.

I’m as interested as you are and I’ve dug deep trying to figure this out.

 

[engineermike]

Even more irritating is that does sells a “thicker” head gasket but doesn’t list the thickness of it either.

 

[GregO]

Even more irritating is that does sells a “thicker” head gasket but doesn’t list the thickness of it either.

Cometic offers a .051"

http://blog.diamondracing.net/inside-diamonds-gen-i-iii-ford-coyote-pistons

 

[K4fxd]

I don’t know, but what I’m going off of is this:
Bore: 3.66
Stroke 3.65
Gasket bore: 3.7
Compressed gasket: .040
Chamber: 59 (mahle catalog page 16)
Dome: 8.4 (mahle catalog page 16)
Deck height: 0.015 (measured)

Is the deck height above or below the deck?

If above the deck -.015 the comp ratio is 11.92

 

[engineermike]

That’s interesting. The gen3 has a bigger dome and larger bore. You’d think they’d be heavier.

 

[engineermike]

Is the deck height above or below the deck?

If above the deck -.015 the comp ratio is 11.92

The pistons are definitely below deck, not protruding

 

[WildHorse]

Chamber: 59 (mahle catalog page 16)

Thought the gen3 chamber volume was 57 cc.

 

[engineermike]

Thought the gen3 chamber volume was 57 cc.

I don’t know but the mahle catalog definitely lists gen2 as 57 and gen3 as 59.

.040 and 57 cc would make it 11.8 though. .030 and 57 would be 12.1.

Sponsored