hot torque? from what i know about torqueing a head and hot / cold you are
asking to break a retainer or crack a head retorquing when hot. it has
always been explained to me to retorque a head after 1 cycle of
cold-hot-cold or in some cases no retorquing (permatorque gaskets)and other
cases after a specific amount of mileage depending upon engine or gasket
manufacturers. if you retorqued a hot engine , upon cooling down the
contraction of the fastners (let alone elasticity of fastners when at
operating temperature) could result in the fastner at more that the
allowable stretch for that fastner wich could lead to a fastner failure. in
adition it could be very possible for a casting to develop a crack in that
same area by exceeding the casting's ability tosupport the torqued fastner .
the cold retorque would result in a more "even" job as in top engine area's
there are also hot spots . combustion chamber and exhaust port areas are
much hotter than lets say intake ports. and depending on design front of a
head vs. rear of a head will show a bit of difrence in temperatures due to
coolant circulation patterns in the block / head. so hot retorque can lead
to some very irregular end torque values vs. cold retorque values being all
normalised to ambient temperature. now if a manufacturer sez to retorque
when hot then by all means follow their instructions! but to date i do not
know of any that reccomend that . i could be wrong! but like i said i'm
not aware of any at this time of writing. and this does not even address
the posibilities of distortion of mating surfaces or tearing out threads in
the block.
chuck.
----- Original Message -----
From "Brent Wolf" <wolfbj at prodigy.net>
To: "Spridgets" <spridgets@autox.team.net>
Sent: Friday, January 25, 2002 6:49 AM
Subject: 1500 head torque
> Listers,
>
> What is the experience, feeling, etc. on hot torqueing the head on the
1500?
>
> I know the Haynes manual does not say to and I have known plenty of other
> manuals for engines that don't say to hot torque, but those heads always
> developed leaks. I have also known several manuals that specifically said
> DO NOT HOT TORQUE for fear of cracking the head.
>
> TAI
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