You probably should have switched off immediately, but the major damage
had already been done. Main or rod bearing failure would cause the
symptoms you mention -- an actual broken rod would have been even more
catastrophic (probably not continued running -- I must admit I've never
seen one). You want to switch off mainly to prevent metal fragments from
circulating through the oil passages, in case you decide to just replace
the bearings with the engine in the car (this may or may not be a good
idea). On teardown, my original engine had 3-inch corkscrew strips of the
#4 main bearing in the sump among other shrapnel, after a similar
experience (I had tried to nurse the poor thing a half-mile to a better
stopping place).
I chose not to attempt a DIY rebuild because the main cap was cracked
through, necessitating align boring. I think your spare engine is going
to come in handy. If you feel up to the task, it can keep your MG
motoring while you rebuild this one. Good luck.
Andrew B. Lundgren had this to say:
>I was shifting from first to second normally. (letting the clutch out at
>a non-speedy rate.) Accellerating normally and I had a bit of a jerk.
>Everything seemed normal enough so I continued and shifted into 3rd.
>(Spooked at this point so I shifted VERY gently.) It happened again, but
>everything seemed ok. I thought It might be a spline going so I was going
>to gently drive it home and then tear it appart.
>
>I continued, stopped at a light and began accellerating again. Then I
>experienced a massive power failure accompanied by loss of oil pressure
>and knocking.
>
>The oil pressure at idle went all the way down to zero. When reved up a
>bit it would build to 25 lbs.
>
>The engine is an 18Gd.
>
>Now, my question, What is broken? I have had a few guesses at maybe a
>spun bearing, or a broken piston rod. Ideas?
>
>(Good thing I didn't tell Larry I was ready to sell my spare engine! :)
>
>
>Thanks!
>
>Andrew Lundgren
>lundgren@iname.com
>
>
>
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the red one with the silver bootlid.
|