Stephan,
Wow, bad news! The engine isn't necessarily trashed. It just depends on
how much cash you have sitting around! I think you're on the right track
- get another runner or engine, as your '69 U20 will take a while to
repair. If you tear down the engine, don't throw away the piston as
it'll be something everyone else will want to see.
When you say vaporized, do you mean "melted" or do you mean fragmented?
If it's the front of the piston, that's where the intake valve is, so
it's possible that something got pulled in. Maybe one of your rings
broke and took the piston top out. That's the only way I could see the
hex screw head causing problems, if it got squished and the metal jammed
the rings. When I cleaned up my pistons, I found some metal jammed in
one of the ring landings, so I know it happens. You should drop the oil
pan, and pop out that piston so you can inspect the condition of the #3
cylinder. If you didn't get any metal fragments dropping below the
piston, and #3 cylinder isn't damaged, it may be possible to re-hone the
cylinder and put in a new piston without pulling the engine. But get
second opinions on this, as you will be better off going the whole
distance by a complete teardown. Let me know what you need as I have the
tools.
Fred
________________________ Reply Separator __________________________
>Subject: Blown engine
>Author: "Sochoux; Stephan" <SSochoux@dbc.com>
>Date: 10/12/99 7:51 AM
>
>A little update on my latest "breakdown":
>
>Pulled the head off last night, front 1/4 of piston #3 is vaporized !
>Head looks fine though. Any clues to look for to determine the cause ?
>I did notice that the head of the hex screw on the throttle shaft
>holding the butterfly (rear carb) was sheared off. Why that would
>happen is a mystery by itself, but would such a tiny head screw crumble
>a piston if sucked in ?
>Anyway, i'm looking to buy a U20 engine or possibly a low windshield
>2000 project car (running) while i pull the motor out. I think it's
>trashed.
>
>Thanks-
>
>Stephan.
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