Scott writes:
>Nelson reminds us of his worn out 200k-mile MGB-GT:
> I had a valve job done on the head about 18 months ago, where all the
> guides and seal were replaced. The head now shows wear in the Intake
> valve guides. According to the machine shop it is due to an over rich
> mixture. He said it is quite common on cars with SU's. True or False?
>Hey, Danny, do HIF SU carbs ever get accused of running rich and spoiling
>valves? (Sigh...)
Sure do! Actually my engine was diagnosed as having either valve or
ring problems which caused it to burn oil. They said 4 or 5 hundred
bucks should fix it. In reality, the rich-running carb. was washing
the cylinders down and preventing the new rings from seating. The two
problems with the carbs were: wrong float in the front carb (yes, there
are 2 types of floats) and a bad seal which caused the choke mechanism
to be "on" all the time (richer mixture). The engine ran fine after
they were fixed.
BUT -- the problem is back! I changed my oil recently and since then
the engine has been consuming oil like a 2-stroke! Unfortunately I
didn't drive the car just before the oil change so I don't know if the
problem really started after the change or not. I was worried that I
overfilled the sump but I don't think that's the case because I'm not
dripping oil as if a seal was broken. I think I might just have to send
the carbs out for a professional rebuild (aaargh).
Any other potential causes? I should adjust the valves and retorque the
cylinder head at this point in the engine's life, any chance of that
helping?
-Dan "destined to never drive this car" Dasaro
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