I've seen that before. I pulled down a motor in a Jaguar 420 that was
running and driving before the teardown. The crank came out in three parts.
It was actually cracked on every main journal and broken completely on two.
The breaks were deep enough in the main bearings to remain together until I
pulled the caps and lifted. I actually thought I had done something terribly
wrong (besides buying the piece of crap). On closer examination, I
discovered the bearing caps were installed mostly in reverse order.
Fortunately I never revved that motor above probably 3000 rpm, because the
car was so ratty and smoked so badly that I didn't dare. I've also take old
motorcycles apart and had the crank come out in two pieces, held together
only by the bearings and the rough surface of the break.
-----Original Message-----
From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net] On Behalf
Of Fubog1@aol.com
Sent: Thursday, August 26, 2004 12:08 PM
To: gasket.works@verizon.net; fot@autox.team.net
Subject: Re: Moldex again, plus rods & link to broken
Mordy another interesting point to note on that photo is the heavy
burnishing on part of the mating faces of the 2 broken areas. This happened
AFTER the shaft broke. The faces were at an angle to each other, creating a
wedging action & resulting in a heavy axial loads, pushing the 2
disconnected sections of the shaft apart. The burnished witness marks were
perfectly aligned with each other fore & aft with the shaft sections
positioned apart from each other, as would be when the engine was running &
power being transmitted. From this the conclusion could be made that this
engine did indeed run for some time with a 2 piece crank, albeit not too
long!
BTW ultimate failure occurred when big end started slamming into the block
hard, but was also progressive as evidenced by witness marks.
Glen
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