Anyone with experience with rebuilding an older 6 cylinder 250 (GM lol)
engine. The unit had been torn down to rebuild but due to unfortunate
circumstances never reassembled. It was stored in an old school bus for a
few years and the crank is somewhat rusted. Underneath the rust the journals
seem in decent shape. Would a polishing make the shaft useable again or is a
regrind mandatory? I used a scouring pad and it brings back some shine but
there is still evidence of rust pits. The cylinder walls also have rust.
Taper us about .006. Pass with a new set of rings or rebore required??
The price for the gaskets, shells, rings tossed in makes this attractive at
$300. Worth a try? How much can a person expect to see out of this thing?
Well it depends on what you want to do.
I would grind the crank, bore it to the first oversize you can find.
Then go from there.
Not sure what Clifford Research still has on hand but they made some
NASTY straight six parts.
Really hard to say without seeing it. Could go either way, a few
(FEW!) minor pits on a bearing surface are not the end of the world,
nor are a few on a cylinder wall, all assuming they are minor. A lot
of huge pits are a very differnt story, however.
If you can polish off the crankshaft journals with crocus cloth to where it
pretty decent, I think you have a fair chance that this will hold.
A short run down the cylinder walls with a fine hone will also tell you how
it really it.
I had a similar experience some time back when I brought engine and pieces
from the machine shop, and it flash rusted in my van overnight. This was
not serious, but I wasnt very happy about it.
This rust is much deeper. This option for a replacement motor will probably
be discarded as of today. Today I've received the offer of two engines
removed from vehicles and still assembled. Neither have run for a few years
but the chances are far better with these. One is stored inside and the
other still on a partial frame covered with plastic. The one stored inside
is felt to be in better condition or the pesron wouldn't have bothered with
it. I'm hoping. And the price is almost free. Part of an estate cleanup. I
have to follow up on these. :)
It would be interesting to see just how far the rusty parts would go though.
If I could get it for next to nothing I'd sure be tempted as a challenge.
Those old vehicles are not too hard to work on and the time spent wouldn't
be that great.
Very slight pitting and damage to a cylinder wall? Yes, I have. Took a
while for the rings to (re)seat, but within about 500 miles it was
only using a quart of oil every 1,500 miles or so. Considering the age
of the engine, the quality of the oil (this was a long time ago), etc,
that was not so bad.
Personally, I'd say there is no yes/no answer. More a 'are you willing
to take the risk that it will not be satisfactory' answer. You may be
happy with the results, and again it may not be what you are looking
I've done some horrible things to engines in the past, and recovered
from them. (for example, one Olds engine so hot the plug wires
litterally burned off the plugs, replaced the head gaskets and that
engine ran flawlessly for several years until I sold it...) Then gain,
I've seen things that one might think were relatively insignificant
cause no end ot problems! YMMV!
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