Bite the bullet Trevor.
You got some bad rings there possibly coupled with worn bores. That's
not to say the valves aren't knackered either.
The 20 psi compression on #3 is a dead giveaway. Heck, with a decent set
of rings, the engine is probably capable of that much compression with
one valve totally out!
Best plan I could think of would be to plan on a total engine rebuild.
There isn't a band-aid solution to this one, I'm afraid.
Rick Morrison
72 MGBGT
74 Midget
On Tue, 29 Sep 1998 01:34:40 -0400 Trevor Boicey <tboicey@brit.ca>
writes:
> (Related to my last post about seeking an engine swap
>for my dead-today MGB engine...)
>
> Before I go writing this engine off, I might as well
>bounce the situation off the list.
>
> 1970 MGB, 18V673Z engine (later than 1970).
>
> When running, car goes through phases of HEAVY oil
>smoke. For a couple of miles, I might get no smoke that
>I can see in the rearview. Then for the next couple of
>miles, any time I push the throttle down I get HEAVY
>oil smoke, as in embarrassing big clouds that linger
>for a few minutes and make pedestrians take alternate
>routes.
>
> Compression is: 125, 60, 20, 105 without oil, then goes
>to 140, 80, 40, 150 with oil. Obviously #3 is in a world
>of hurt and generally the whole engine seems knackered.
>
> Head gasket was just installed by me last december when
>I opened the engine for an inspection. I am not a trained
>eye at these things, but everything looked good at that
>time. Engine ran fine since then although used only for a few
>hundred miles because of body restoration.
>
> Normal wisdom seems to say that if oil doesn't improve
>compression, then it's a valve problem. However, from
>the amount of oil smoke I am putting out, could it be
>valves? I am thinking I might have a SEVERE ring problem,
>something that oil just isn't really going to hide for
>even a few strokes on a compression tester.
>
> I intend to pull the head off and investigate, but would
>like to have a plan first. I don't want to make the car
>immobile if the engine is done for, although I guess I could
>reassemble with the old gasket and it should run enough so
>I can move the car around my driveway.
>
> Any chance this could be salvageable with a used head
>or even less? I am prepared for the eventuality of total
>replacement, no big deal, but if there is a chance I might
>get away with a cheaper and faster repair, I should explore. I
>am not above throwing new rings in as a DPO repair if
>it gets the car running again. ;>
>
>--
>Trevor Boicey, P. Eng.
>Ottawa, Canada, tboicey@brit.ca
>ICQ #17432933 http://www.brit.ca/~tboicey/
>
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