CR is right on here, never use anything but bronze guides in these
heads, or any head as far as I am concerned. Try to get some $$$ back
from this shop and find someone who can do this right.
Regarding MMO, is is just a thin oil, a solvent really, with a little
wintergreen oil in it. I don't know if that is for the fragrance or it
actually does something! It has obviously been around for years, and the
private aircraft pilots are big believers, since it keeps their engines
clean as clean as the proverbial whistle.
I've used it to free up sticky lifters. I have also added it to the oil
during new engine break in. No problems yet.
Charley & Peggy Robinson wrote:
>
> If the valves are sticking it's because the machine shop didn't allow
> enough clearance between the stems and guides. When the engine warms up
> what clearance there is disappears and the stems seize in the guides. I
> suppose the MMO makes things a bit more slippery.
>
> The valves are sure to be galled by now, so the head needs to come
> back off so the valve job can be redone. The spec on the clearance
> gives a range of values. It's possible to be on the low side of the
> spec and have the exhaust valves seize up, especially on the center
> cylinders, which run hotter than the end one. Been there, done that.
> BTW, if a machine shop doesn't install bronze guides it's usually
> because they don't have the special tools for the job.
>
> CR
--
Stuart MacMillan
Seattle
'84 Vanagon Westfalia
'65 MGB (Driven since 1969)
'74 MGB GT (Restoring)
Assisting on Restoration:
'72 MGB GT (Daughter's)
'64 MGB (Son's)
Parts cars:
'68 & '73 MGB, '67 MGB GT
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