Re: [Amc-list] Torque vs Re-Torque

[Frank Swygert <farna@xxxxxxx>]

Bruce, you are 100% correct in the first part -- the old head gaskets needed to be torqued after a relatively short period to bed them in. Modern ones don't need this, even with the 196. There's something about the design of the engine, however, that REQUIRES retorquing the bolts every other year or every 12-15K miles. The TSM says every 8K, but I believe the better head gasket materials are what allows at least a 50% longer interval. I know from actual practice that if you don't retorque the head bolts occasionally it WILL blow the gasket, run hot, and 80% of the time warp the head (I would say 50%, but these things are OLD now and less forgiving -- and most, if not all, have been run hot a time or two before). How long can you go? I have NO IDEA. I'm also not willing to find out, or put someone else up to finding out. Retorque it every other year or 15K, whichever comes first. That's the SAFE thing to do! Occasional drivers on short trips with perfect cooling systems MIGHT 
 get by with much more. It's not that hard to retorque the head every other year though, and only takes about an hour. Doesn't your Rambler deserve it? 

------------------
Date: Wed, 19 Dec 2007 20:01:28 -0500
From: "Bruce Hevner" <scramblr@xxxxxxxxxxx>

If you are using an old shop manual they are probably referring to the old
asbestos sandwich type head gaskets. These DID need to be re-torqued at
least a few times until they bedded in.
 If you are using a modern non-re-torque head gasket you should not need
to re-torque it. If it's possible to do I usually re-torque my heads at
the 1000 mile mark and then about 15k.  OR if the engine has been run hot
but not yet blown a gasket.
This ONLY holds true for the non-torque to yield type bolts. Most modern
engines are now using torque to yield type head bolts. When originally
tightened these bolts are put in a state of stretch and should NOT be
re-torqued OR reused!!
I always back off my bolts about 1/2 turn before re tightening them. This
releases the "stiction" of the bolt. Head bolts tend to become stuck in
the threads preventing them from being tightened any more if you don't
loosen them first.
 This is ONLY MY OPINION of what to do. I would ALWAYS call the gasket mfg
and get their recommendation since it's their product.
But HEY,,, that's just ME!
Bruce Hevner

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)


_______________________________________________
Amc-list mailing list
Amc-list@xxxxxxxxxxxx
http://www.amc-list.com/mailman/listinfo/amc-list