David,
Having been in the business since 1976, I've seen the insides of a lot of
engines. It has been my experience that valve seat recession and burnt
valves are most often a problem from the use of unleaded gas in engines
which do not have hardened exhaust valve seats when the cars are driven at
constant rpm, as on long trips at steady road speed. Around-town use does
not seem to cause the problem to manifest itself so quickly, although it
will eventually happen.
As to how to treat a new engine that has sat for a long time, assuming that
it turns over freely (suggesting it was assembled with adequate assembly
lube), simply add the required amount of oil (cheap 30 weight is best for
the break-in period), spin it over with the starter motor while the spark
plugs out until pressure registers on the gauge, refit the plugs, start the
engine (making sure there are no fuel leaks), bring it up to temperature by
running it at a steady 1,800 rpm (which also makes sure the cam breaks in
properly), then shut it off, re-torque the head nuts in the proper sequence,
re-adjust the valves, then re-start it and adjust the carbs and timing. If
the engine is stiff to turn over with the plugs out, squirt some light oil
into each cylinder and see if that frees things up. If it is still slow to
turn over, then you have to assume there's a problem and a tear-down would
be advisable to find the problem.
Lawrie
British Sportscar center
----- Original Message -----
From: "David Macedonia" <david.macedonia@verizon.net>
To: "MG Mailing List" <mgs@autox.team.net>
Sent: Wednesday, January 07, 2004 6:54 PM
Subject: Hardened Valve Seats
> All,
>
> While we're on the topic of hardened valve seats, can someone tell me how
> necessary they really are? When I had the machine shop overhaul the block
> back in '97, the owner insisted that hardened seats weren't necessary if
the
> car wasn't going to be a daily driver? What you all think?
>
> On a different topic, it's been 6 years (yikes! time flies at my age),
since
> I completed the restoration of the engine. Unfortunately, it's still
> attached to an engine stand waiting for a car to go into! Hopefully, now
> that shell is back from the restoration shop (they did a wonderful job),
> I'll have it back in the car before the Summer. Are there any special
> precautions I should take prior to cranking the engine for the first time?
>
> Thanks,
>
> Dave
> 1966 MGB
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