Re: Subject: Faulty 1750 oil pump

["Jay Mackro" <jmackro@domain.elided>]

Edward Solstad <esolstad@domain.elided> had asked
>
>We just had an aftermarket 1750 oil pump seize on a rebuilt engine. The
>engine had been started with all vital signs showing OK. Upon a subsequent
>start up, the pump seized. When the replacement pump arrived, it was
>determined to not spin freely - obvously from the same source and not
>suitable for installation.  Has anyone had recent experience with 1750 
>oil pumps and can you recommend a reliable supplier? 

Ed:

When you say that the second pump did not spin freely, do you mean
the pump by itself, or after it was bolted to the front cover?  There is
a procedure for mounting oil pumps to the front cover.  If this procedure
isn't followed, they will often bind, usually resulting in the shaft 
shearing shortly after installation. Pages 36-37 of the book by Jim
Kartalamakis "How to Power Tune Alfa Romeo Twin Cam Engines",
give a sketchy description of how to mount the pump.  The key is
that the pump shaft isn't normal to the mounting surface, and there
seems to be some "tolerance" in the angle of the pump's mounting 
flange.  So, if you just bolt it on, the shaft will probably be misaligned
in the bore of the front cover.  Instead, you need to just snug up the
bolts, making sure that the shaft can rotate freely.

On the other hand, if your pumps aren't turning "out of the box",
then yea, it's time to find a new supplier.

Jay Mackro who had a great time at Ed's Great River Rally in '98

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