[Supras] Question about head gasket (hopefully last)

[t72pwrd]

IIRC the 1/2J motors came with MHGs from the factory.  I think that was the 
biggest reason they don't blow as frequently as a 7M with a composite 
gasket.

Don't worry about adding fuel to a flame war, this list can certainly 
withstand it.  I actually miss the frequency of the flame wars from a few 
years back.  They were entertaining, fun to engage in, occasionally 
educational and always resolved peacefully :-)

BTW, if it was "cumulative end to end differential expansion" why doesn't #1 
blow too?  Put that in your pipe and smoke it you lousy &#@!#$$%^%!  LOL!


----- Original Message ----- 
From: <berniek at technicaldevelop.com>
To: "Craig Thommes" <cthommes at adelphia.net>
Cc: <Supras at supras.com>
Sent: Sunday, June 04, 2006 6:24 PM
Subject: [Supras] Question about head gasket (hopefully last)


> Inline 6 cylinder engines are probably the longest which use aluminum 
> heads and iron blocks.  Other engines have shorter heads, which minimizes 
> cumulative end to end differential expansion or head warping.  Most 7M 
> gasket problems happen at the sixth cylinder, apparently due to cumulative 
> differential expansion.  My JDM engine showed deep grooving in the head 
> and block around the stock gasket crimped rings, especially at the ends, 
> presumably from tendencies of the block and head to "walk" with respect to 
> each other due to thermal cycling.
>
> I do not want to add fuel to a flame war here.  I just want to know what 
> the consensus is regarding life to be obtained from a 7M with a Cometic 
> gasket (mine was special ordered as 2 mm thick).  I'll be running 14 PSI 
> boost and ARP head studs.  I'd like to be able to get 150K miles with 
> periodic retorquing if needed.  Got that from the stock head gasket with 
> 72 Lb-Ft. retorquing at 8 PSI.
>
> Just out of curiousity, what did Toyota do in the 1J and 2J engines to 
> eliminate the problem?
>
> Thanks.
>
>        BernieK
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