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Tom Timmins

Testing early oil pumps

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I have a 1911 Regal motor that was rebuilt some years ago but never used. It has an oil pump mounted on the backside of crankcase, but no way to verify that it is actually working. The car is done and ready to go but I am concerned about the oil. Any ideas?

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Depends what kind of oiling system it has. If it were a modern motor you could pressurize the system from a sealed container of oil under air pressure, feeding oil to all the bearings before you start it up. Some early motors had a low pressure drip feed system, that can be oiled up before it starts.

 

In some cases you can remove the spark plugs and turn the engine over by the starter or by towing, until you get oil pressure.

Edited by Rusty_OToole (see edit history)

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I'm currently dealing with this situation myself and I suspect that, while it should pump oil, there is very little measurable pressure, at the most 4 or 5 pounds. Many very early oil pressure gages only go up to about 10lbs. which suggests that internally the oil was just dripping on to the bearings. I'm not familiar with the Regal but in 1911 only a very few extremely high end cars had drilled cranks and internal oiling. Is there a sight glass on the dash? They were common, often a little spinner under glass the simply turns letting you know the oil is moving. A drip sight gage is also practical. In any case, I would install something visible because even if it is working now, with nothing to check you'll never know if it fails until a bearing melts.

 

It is almost certainly either a gear pump or a plunger pump. Both are very simple and the only thing that is likely to cause failure is wear... and by definition, since they are usually full of oil, they don't wear much, but its still worth the effort to dismantle them and check everything. For instance, if it is a plunger pump and you can wiggle the plunger, chances are its too loose. Clearance should be in the neighborhood of .001-.0015. You won't be able to feel that but you can probably feel .003. Gear pumps have similar clearance around the outside of the gears and if it has a bronze bushings the pins the gears turn on need to be checked as well as the clearance top and bottom. While very simple, both types rely on very close tolerances to work.

Edited by JV Puleo (see edit history)

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Is it a gear pump or a cam operated plunger pump (which scares me to death)?

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Is it a gear pump or a cam operated plunger pump (which scares me to death)?

It is a gear pump? I may try loosening a cap on top with the motor running to see what happens.

Thanks, Tom

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Is there no place to put a pressure gauge or tell tale? All cars should have some provision to check oiling, except possibly pure splash systems.

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Is the oil pump submerged in oil at all times?

Early Dodge pumps are above the oil level so require priming if the oil lines have been disconnected.

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Gear pumps usually wear into the flat backing plate.  Most can easily be restored by using a belt sander to flatten the plate. 

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You can remove the pump submerge the gears in oil and rotate the shaft with a drill motor and watch the discharge.

Regal pumps only have a point contact in back of the gear chamber a solution I have used is to make an insert to create a gear pocket.

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