oil system mods that help

Discussion in 'Oil and Lube Systems' started by grumpyvette, Sep 29, 2009.

  1. 87vette81big

    87vette81big Guest

    Without a Doubt in my mind the Bypass Valve is open 100% of the time in a Pontiac V8 with The stock oil pump, M54D & M54F 40-60-80psi oil pumps respective when on the gas WOT ABOVE 2600RPMS.

    opening and smoothing the recessed area and porting the oil passage entrance reduces the restriction to oil flow
    [​IMG] [​IMG]
    notice the open slot between the rear main cap supporting the oil pump and bearing shell support and the area supporting the rear main seal, this prevents PRESSURIZED oil from the bearings reaching the rear main seal.
    the as cast recess in the rear main cap where the oil pump mounts can be rather restrictive and shallow
    Ive seen this frequently, and almost always its a case where if you measure carefully, youll almost surely find,
    the oil pump drive shaft is bottoming out solidly between the oil pump and the distributor gear is binding,
    so the distributor is not firmly seated against the intake manifold surface.
    the oil pump drive shaft length MUST BE about .050 SHORTER than the distance it would take to firmly seat it inside the distributor drive gear, the cam has a gear that spins the distributor and the oil pump drive shaft is driven by that distributor gear in the lower distributor that extends down to the oil pump drive.


    this gear must not bind on the distributor too oil pump drive shaft when the distributor is seated firmly on the intake manifold and clamped into place there must be about .050 clearance minimum



    related threads you should really read








    Last edited by a moderator: Jan 12, 2018
  2. Strictly Attitude

    Strictly Attitude solid fixture here in the forum

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