lowest oil pressure for engine to survive

[Jack Shaft]

As long as the bearing requirement is satisfied additional oil pressure is nothing but a load on your engine.Insert bearings require additional pressure than whats needed to satisfy the hydrodynamic principle,this few pounds of added flow and pressure help keep the bearing cool and clean.Only a slight amount of flow/pressure is needed to accomplish this,your increasing the flow through a .0015 gap in a 2" bearing..Anything more looks good on the gauge,but isn't necessary.
Ford satisfied the bearing requirement on the model a engine with gravity,oil is pooled about 3 inches above the main bearing and flows down a tube to feed the mains. The model b engine with pressurized mains ran about 5 psi pressure,enough to do the job.
Companies that make high volume/pressure oil pumps are in business to make money,if the customer is comforted by high pressure then they will fill the need.

[40 Deluxe]

Originally Posted by alanwoodieman

40 deluxe, what we are think about is the high volume pump which happens to be the 80# variety, actually what we are looking for is more oil flow not necessarily a lot more pressure

Well, the extra flow from a high volume pump has to have somewhere to go (through loose, worn bearings) or else it just gets churned through the bypass (relief valve) wasting power and heating the oil. Since there is no need for 80# of oil pressure, just replace the relief valve spring with one that opens at a lower pressure.

[alanwoodieman]

we are looking for more flow-flow-flow using an high volume oil pump with the helical gears should do that and leaving the 50 # relief under the manifold should control our oil pressure. going to do this just to waste time and energy and a pan gasket plus get every one on this post the chance to add their two cents worth. we will see what gives probably next week. stay tuned for more fun on old ford flatheads!!

[Ol' Ron]

the bennafet racing gives to these engines is: A prolong period of time to observe the modifications you've made to your engine. This comes in two areas. One performance.Two reliability. To build an engine that has the power to run 200 mPh at bville and stay together for several runs. or a stock car engine that runs at least 50 laps every saturday night for several weeks, and beyond. oil pressure and cooling are the two things that make this possible, and we learn by our mistakes.

[alanwoodieman]

well better late than never--Monday/Tuesday we will know what an high volume 80# pump does for our problem

[F-ONE]

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The oil filter can rob some of the pressure if the wrong fittings are used.

[Brian]

So, how does oil being dumped by the relief valve get heated anymore than the oil flowing through the bearings, removing heat from the bearing as it does so? If the oil going through the bearing is removing heat from the bearing, it is doing so by absorbing that heat. Oil returning to the oilpan through the relief valve is doing exactly that; returning to the pan. So how is it getting heated? Surely it is at the same temperature upon leaving the pump as the remainder of the oil that circulates throughout the rest of the engine?

[Ol' Ron]

Brian The relief valve has a spring, which must be overcome to open, allowing oil to escape. When building hydraulic power supplies for the machintool industry OSHA required us to reduce the noise of the supply. We inclosed the supply and installed a cooling system. We installed sensors on all the components in the unit and the relief valve was one of the hottest.

[JSeery]

Originally Posted by Brian

So, how does oil being dumped by the relief valve get heated anymore than the oil flowing through the bearings, removing heat from the bearing as it does so? If the oil going through the bearing is removing heat from the bearing, it is doing so by absorbing that heat. Oil returning to the oilpan through the relief valve is doing exactly that; returning to the pan. So how is it getting heated? Surely it is at the same temperature upon leaving the pump as the remainder of the oil that circulates throughout the rest of the engine?

It takes energy to move the oil. The higher the pressure and flow rate, the more energy required to move it. I think the biggest issue is the energy losses. The energy loss can be in the form of heat. But the main activity going on is more resistance in the pump to move more oil. And a lot of that energy is being dumped out the relief valve.

[Mart]

All I know is that when as a kid I used to put my finger over the end of the bicycle pump, when I pumped it got hot really quick.

[alanwoodieman]

installed 80# high volume oil pump, 20w50 oil, started up at 60# at idle, warmed up the engine, drove about 20 miles, goes down the road at 30/35# ( compared to 7/10# before) at 50 mph, idles at 7/10# hot (compared to 0# before) guess we will see how long this last. told owner to save his pennies for a rebuild

[Karl]

Isn't flow just as important as pressure ? I had a friend who rebuilt his Austin ( Bantam) 7 He narrowed the oil feed pipe to the dipper wells . On the dash he had great oil pressure at the dipper wells he had less oil and he ran a bearing -Karl

[GB SISSON]

Originally Posted by fortyonerag

The ol' 'Lucky Dip'.

We always called the 216s a babbit beater. Of course it was 54 when gm went to a full pressure 'real' system.

[Tinker]

...

[russ40standard]

Originally Posted by alanwoodieman

installed 80# high volume oil pump, 20w50 oil, started up at 60# at idle, warmed up the engine, drove about 20 miles, goes down the road at 30/35# ( compared to 7/10# before) at 50 mph, idles at 7/10# hot (compared to 0# before) guess we will see how long this last. told owner to save his pennies for a rebuild

80# high output oil pump replacement by alanwoodieman was successful (I'm the owner). Added 1/2 quart of Lucas per recommendation, and the oil pressure is now good on this million mile engine. I have no history on the engine. A side benefit of replacing the oil pump is that a new rear seal has reduced the oil leakage when parked in the garage by 90%. Down to "normal" leakage now.

[Zeke3]

Welcome aboard. Glad to hear the update is working out for you.

[Mart]

Glad you have reached a solution.

[Tinker]

So lucas oil is thicker... higher oil pressure? You can run straight 30w to do that. Friction cases heat, the thicker the oil the higher the temp... but higher gauge pressure..... High Oil pressure is hype.

[Tinker]

OP Be happy....

[russ40standard]

I was running 20W50 Kendall before the oil pump replacement, with as much as 1.5 qts of Lucas mixed with the oil....Pressure was way low, under 8 lbs at speed, zero at idle. Also, I tried straight 40 weight before the oil pump replacement....No difference. After the pump replacement, I was getting pretty good readings on 20W50 Kendall before adding the Lucas. Picked up maybe 3-5 lbs extra oil pressure with the 1/2 qt Lucas. The new high volume pump was the solution to this issue. Lucas was icing on the cake. Thick icing for an old engine with an unknown history.