On Feb 19, 7:50am, Kendall Robinson wrote:
} Subject: Seized motor (Rebuilding?)
}
} The pistons are frozen, but good.
} My question is, does anyone have experience getting pistons out of a seized
} motor. I've tried penetrating oil, sharp rap on the top of the pistons....
} to no avail. The reason it's seized is because someone took the head off it
} and left it like that (it was still in the car, and the hood was
} covering it).
Yea, the International T6 I used to level for my shop had been sitting in
a filed for 7 years, with water running into the manifold, and filling
up a couple cylinders. I freed them still connected to the crank.
first- let them soak- kero, WD-40 are good candidates. If you have the
crank off, then all you have to worry about is one cylinder at a time.
Get a fat hunk of wood, and tap down on the piston. (hit the wood with a
decent weight mallet.) Work around the edge of the piston. Get on it
from below as well. It should work loose. If not, the worst cases are that
you'll damage the piston, (break it out if you have to!) and possibly
scratch the cylinder walls some. (You can then have the cylinders rebored,
which they may need anyhow.) No matter what, you'll have to at least
hone the cylinder walls to get rid of the surface rust. (Don't overhone-
you don't want to enlarge the cylinder)
On the T6, I had a 6'+ breaker bar hanging off the crank bolt-
*jumping* on it! (Leverage + dynamic weight force was pretty huge)
after a couple HOURS, the FRONT piston began to wiggle slightly.
More pounding on the pistons with a 2x4, and working back and forth
on the breaker finally started to loosen the pistons. (I had to
hone one peticularly rusty cylinder before even starting this!)
Finally, I was able to turn it over- many times to completly free
up. Then the head and lifters, which were also rusted in place, were
cleaned up. I never pulled the pan. (We're talking a 6 ton machine
here- not too easy to much around with) It all went together, and
now runs fine. The cylinders were honed some, but I never removed
the pistons.
} I'd hate to give up on the motor, all the bearing surfaces are in really
} fine shape. It doesn't look abused except for this slight problem of
} being seized. Ideas?
No problem. Worst case is the overbore and new pistons, which you
might need anyhow. And, you may get lucky, and get away with a light
honing and new rings. (Don't re-use the old rings, not if you've got
the engine apart anyhow.)
________
/___ _ \ Roger Garnett (garnett@BATCOMPUTER.TN.CORNELL.EDU)
/| || \ \ Agricultural Economics |
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