CLANK VI: Quality Woes
Got my cylinder head back from the machine shop last night. Sprayed it glossy
black, and proceeded to install it on the block. New head gasket, of course,
and all new head studs, washers, and nuts. Antiseize on the stud threads where
they penetrated the block. Oil on the protruding threads. I was doing it
right.
While I was torqueing down the head, stud #3 didn't seem to be taking the
torque as well as the others. You know that funny sinking feeling, when you
turn, and turn, and the torque doesn't go up? Well, it wasn't quite that bad,
but it definitely felt "soft". It *did* get up to 105 foot-pounds, just like
the others, but the "feel" disturbed me enough, so that I torqued the head back
down again, and pulled the stud out to have a look. Nope, the lower and upper
stud threads looked fine, and it was fully screwed into the block. I put the
stud back in, and torqued up the head again. Getting stud #3 back up to 105
ft-lbs proved to be a problem. At about 100 foot-pounds, there was a *click*,
and the nut twirled freely.
"Oh, my god", I thought, "I've stripped the threads down in the block". But
the problem turned out to be in the nut ( WHEW! ). The threads in that
brand-new $1.00 Moss nut had stripped right out of the body. They were still
in one piece, and looked for all the world, like a helicoil. Has anybody else
seen a failure like this?
- Jerry
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