Board index Flathead Power-Technical Questions, Answers, and Suggestions Knuckles 41-47 oil pump governor-purpose and use or not use?

41-47 oil pump governor-purpose and use or not use?

Just putting my original oil pump on the knuck and am contemplating using the governor. The original manual says it controls low and intermediate speed oiling (reducing it???) but the Knuckle "Bible" says that it sends more oil directly to the pinion shaft at high rpm and just dumps surplus oil back in the gear cavity at low rpm so I am confused as to it's purpose and need?

I have been fighting too much oil in the engine (hence trying an original pump) and want to be sure this time around. Any thoughts out there?

Posts: 530
Location: Ogden, Utah, USA
My understanding of the oil pump "governer" was to reduce volume at low speeds and low temp. To help prevent over oiling the top end when oil and motor were cold. My regulator(same thing) lost the drive ears long ago. I took it out and fished out the litle bits of metal that used to be the drive ears. Put it back to gether and it has worked just fine for 10 years or so. My friend put a "Pan" pump cover on his and has had no trouble for about the same amount of time. IMHO there are other ways to prevent over oiling the top like reducing the outlet om the cam cover that feeds the oil to the rocker boxes. That would make the regulator un-needed. Other than the two extra tablespoons of oil in the cavity where the regulator used to reside I can't think of a major issue that removing it might cause. Some one with more knowledge about pumps than me might have a concern. If so I hope they would speak up and let us know. :) Steve
Steve H

Posts: 93
Location: Norway
As I understand it the regulation of the early knuck oiling system functions in similare way of the BTSV. Pressurised oil supplies pinon shaft and top end. At high speeds (or cold oil) the pressure relief valve opens slightly to regulate max pressure. The surplus flow over the relief valve is directed to lube the timing chest. Below this speed no surplus oil is present and the timing chest is instead lubed with oil comming from the governor.

The delivery rate of the pump is fixed and determined by pump gear size and speed. Delivery of oil is proptional with rpm. You can only alter where the flow is directed.

Having looked closely at the design of the system - as soon as the pump starts to build pressure, the check ball is moved off its seat which uncovers a drilled passageway to the rotor and to the pinion shaft oil passageway. Therefore at low rpm some of the pressurized oil goes to the rotor/governor (with the rest going to the pinion shaft and top end) which bypasses to another passageway linked through the pressure bypass system directing oil into the cam chest. This is how the oil volume/pressure is reduced slightly at low rpm. When the pump reaches a certain speed the rotor/governor closes by centrifugal force allowing the system to perform normally as if the bypass system was not present. In this situation the pressure regulator ball and spring assembly take over and bypass high pressure oil into the cam chest. Naturally, when the rotor/governor is "closed" the pinion shaft and top end receive full pressure. Thanks to all who responded and I hope this explanation is clear. The question is: how much does the system really reduce the volume/pressure at lower speeds? Indications from experts lead me to believe that the change is negligible and probably not worth the hassle/risk of the rotors drive tabs breaking off or other related issues.

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