Oil pump rebuilding

Mofosheee said:
Sorry for the delayed response. After disassembling & visually inspecting the 50 year old pump and prv I thought eff-it and ordered a new parts from Andover.
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Good luck & please let us know how your new pump works out. I have done same as you mention here and ended up with a NEW pump (not from AN but their competitor) that immediately wet sumped down to the oil tank screen in just a few days. A careful lapping of that new pump improved it significantly. However after reworking several Norton oil pumps down to very close tolerances (under .001" measured clearances) and monitoring them in action I believe Ashley from AN's observation is correct... i.e. Norton oil pump design is such that wet sumping is inevitable. The answer is a properly reworked close-tolerance oil pump (clearances LT .001") in combination with one of several available excellent crankcase sump reed valves (NYC Norton, JS engineering, etc.) addresses the situation.
 
Rockithound said:
Good luck & please let us know how your new pump works out. I have done same as you mention here and ended up with a NEW pump (not from AN but their competitor) that immediately wet sumped down to the oil tank screen in just a few days. A careful lapping of that new pump improved it significantly. However after reworking several Norton oil pumps down to very close tolerances (under .001" measured clearances) and monitoring them in action I believe Ashley from AN's observation is correct... i.e. Norton oil pump design is such that wet sumping is inevitable. The answer is a properly reworked close-tolerance oil pump (clearances LT .001") in combination with one of several available excellent crankcase sump reed valves (NYC Norton, JS engineering, etc.) addresses the situation.
Click to expand...
Not suprised a new pump wet sumped that quickly. I had to rebuild an ES2 for a client. That engine had a new oil pump fitted when it came to me. Done hardly any miles but the clearances in the pump were nowhere near what they should have been. I'm of the opinion that the new pumps are made with clearances wider than optimum so they are able to turn easily with the fingers, when actually a new or rebuilt pump should be stiff to turn.
 
Rockithound said:
Good luck & please let us know how your new pump works out. I have done same as you mention here and ended up with a NEW pump (not from AN but their competitor) that immediately wet sumped down to the oil tank screen in just a few days. A careful lapping of that new pump improved it significantly. However after reworking several Norton oil pumps down to very close tolerances (under .001" measured clearances) and monitoring them in action I believe Ashley from AN's observation is correct... i.e. Norton oil pump design is such that wet sumping is inevitable. The answer is a properly reworked close-tolerance oil pump (clearances LT .001") in combination with one of several available excellent crankcase sump reed valves (NYC Norton, JS engineering, etc.) addresses the situation.
Click to expand...
Installed a new pump and PRV................45psi cold @ start up. When up to operating temp, pressure drops and drifts around dependent on rpm.
No wet sumping noted (yet) I'll take it!
 

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