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Seized Engine.. an additional note..

Ben commented on my comment of checking piston to deck height:

>> 3. Worstest case (and not as likely) - you also bent the crankshaft. The
>> only way to really determine this is to remove the head and measure the
>> deck height of each piston (how far below the head they come up). ALL should
>> be the same, +/- a very small tolerance. If this is the case - I would look
>> for a new engine, it just isn't worth doing a rebuild on an engine this
>> damaged, parts and labor will exceed the cost of a short block.
>
>Measuring the piston heights for a bent crank assumes that the connecting
>rods are not bent.  The easiest way to get an idea if something major is
>wrong is to first let the water out (pull the plugs and turn the motor over)
>and then do a compression test.  Slightly bent rods will still allow the
>motor to turn, but compression will be down on the affected cylinders.
>
>Ben

If you think about it a bit - the bent rod will result in a piston that does
not come up as far as the others (the distance from the top of the piston
to the top surface of the block - called deck height). THIS is what would
cause the compression to be down on the affected cylinder(s). Since the bending
is not likely to be massive - I doubt if you could reliably tell anything
about bent rods with a compression test. A perfectly healthy engine can
have differences of +/- 10lb/sq/in.. and to really do a compression test
would require the starter to to turn the engine over, risky at best
given the history of the engine until it is torn down.

As far as how the water got in - I would guess that it could also come
in through the intake, but I have also seen cars where it backed up
the exhaust after the engine stalled. Either way - it's bad and
expensive news.

Best..

=======================================
Don Eilenberger (dje@domain.elided)
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  '79 R65 FrankenCycle - der Beemer
  '87 535i BOHICA      - der Bimmer
  '75 25' Hunter       - das Boot
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DOD#1177, BMW-CCA#104316, BMW-MOA#64000
President - New Jersey Shore BMW Riders
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        "A glutten for clubs.."
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