RE>Re: Oil pumps
Andrew Green writes:
I understand it is basically just two gears meshing together. The
two kinds of failure I've been told about are (1) the pickup screen getting
clogged, which is obviously a repairable problem if detected before the engine
goes, and (2) the gears getting so worn that there's a lot of slop and space
between them, allowing the oil to squish around instead of move forward.
**** When I rebuilt the Clankster's engine, I was unable to get a new oil pump,
so I
"clearanced" the old one. Apparently, the important wear on these pumps is in
the axial direction. That is, the gears wear away the case where they rotate
against it. In the case of the TR2-4 engine, there is a flat cover plate that
bolts up to the pump body. To clearance the pump, I pulled this plate off.
You could
see where the gears had worn deep grooves in the plate.
First, I flattened the plate by rubbing it on sandpaper over a sheet of
glass.
Then I measured the coverplate-to-gear clearance with plastigage. I sanded
down
the pump body until I saw .001 on the plastigage. Then I polished off the
cover
plate with fine grit sandpaper, winding up with crocus cloth.
The Clankster now enjoys excellent oil pressure, and it only cost me a
couple
of bucks for sandpaper, and about two hours of really boring work :-).
( plus a grand and a half for a complete engine rebuild, but we won't
talk
about that, will we? )
- Jerry
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