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Re: Another Intake Manifold Mounting Question

To: buick-rover-v8@autox.team.net, SteveMines@verdugohillshospital.org
Subject: Re: Another Intake Manifold Mounting Question
From: Lar Kaufman <lark@world.std.com>
Date: Tue, 24 Jul 2001 12:59:10 -0400 (EDT)
There may be something better, but you can generally find Champion 
spark plug thread lubricant at auto parts stores. This "lubricant" 
is considered suitable where torque values are important (e.g. aviation
engines). The actual lubrication is provided by mica particles in 
suspension. Even if all lubricating oils are baked out, there is 
sufficient mica trapped in the threads to allow the (sparkplug, nut, 
stud...) to be removed, because the mica particles shear and release
some of the frictional binding. N.B. you don't want graphite, which 
at exhaust temperatures will tend to cook into iron, causing some 
embrittlement of exhaust fasteners. In other words, lubricant specs 
for exhaust manifold threads is more critical than intake manifolds
and you really need to use the recommended antiseize compound based
not only on expected temperatures but the alloys, fastener size and
torque, etc. that presumably the engineers have carefully considered
for the application. (On the otherhand, I have been known to use 
high-temperature RTV as a "thread lubricant" to secure catalytic
converters because the temperatures reached caused erosion and 
molecular binding of nuts to the studs. The high-temp RTV seems to
prevent that, and even keeps exposed threads that protrude beyond 
the nut from degrading; the threads "clean" themselves on removal 
of the nut.)

 -lar
"We, too, who look upon the loom are deafened; and only when we escape it 
shall we hear the thousand voices that speak through it....  Ah, mortal! 
then, be heedful; for so, in all this din of the great world's loom, thy 
subtlest thinkings may be overheard afar."  - Herman Melville, _Moby Dick_

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