oil pressure

[BeBop138]

On the new engine I put in a new oil pump from VPW it is a high pressure-high volume pump---it runs about 55-60lbs at idle and it goes to around 70 at high RPM. Shows this on a Stewart guage on the engine block and between 50-60 on the dash guage---is this to high or??

[martybose]

If it is safe to assume that these numbers are when the engine is cold, it's not a problem. The oil pressure will drop as the oil warms up. If you are concerned about it, you can always change to a lighter weight oil.

Marty

[BeBop138]

Marty, it runs at these pressures hot or cold, it does increase some as the rpm`s go up. It seems ok, no leaks, usually good pressure as this is wanted--just don`t want to damage anything.......Lee

[Don Coatney]

What is the factory recomendation?

[BeBop138]

What is the factory recomendation?

Best I can find in my manual is 40-60lbs above 30mph--another section said 40-50lbs at 40-50mph-----could not find specs for idle pressure----it appears I might be on the high side for idle. Again new pump is higher pressure and volume, this probably changed the stats----I will call VPW for specs on pump...............Lee

[Jim Saraceno]

Are we talking about a flathead six? If so, that sounds high to me. I think I'd check my relief valve.

[BeBop138]

Are we talking about a flathead six? If so, that sounds high to me. I think I'd check my relief valve.

Starting to think this way also---better safe than sorry--265 six......Lee

[BeBop138]

OK, I took out my relief valve and checked it out, looked good so I cleaned it up and it slides nice in the bore. Still 60lbs at idle. Called VPW on the pump and he said it depends on the bearings and said my machine shop did a good job on the clearances and that 60lbs was ok----I guess if it works don`t fix it

[martybose]

You've never said (at least in this thread) what weight oil you're running?

Marty

[BeBop138]

You've never said (at least in this thread) what weight oil you're running?

Marty

I think I used 10/40 Castrol

[aero3113]

BeBop, have you gone on any long drives yet to let the oil warm up? If so what is the oil pressure after the drive?

[BeBop138]

BeBop, have you gone on any long drives yet to let the oil warm up? If so what is the oil pressure after the drive?

It has not gone far --3-4 miles but I have let it get to operating temp and idle time has been 20 minutes when I was checking it out. Pressure stays the same. Would air in the lines be a problem? Edited June 15, 2010 by BeBop138
more info

[aero3113]

I guess air in the line could be a factor. You could maybe burp the line at the gauge.

[james curl]

I believe that the oil pressure gauge is a bourdon tube gauge and will measure any type of postive liquid or air pressure. The oil would pressureize the air trapped in the line and try to straighten the coiled bourdon tube out causing the needle to move. My original Plymouth servcice manual states under the oil pressure gauge the following "The tube should have air in it to cushion the pulsations of the oil pump and oil relief valve. The Dancing pointer may be the result of a leak in the oil gauge tube or improper installation. To correct this condition, disconnect the tubing at the gauge and the engine block and drain out the oil. Reconnect the tubing at the gauge first then at the block." From this one could conclude that the gauge measures air pressure and not the liquid oil pressure. I hope that this helps clarify the operation of the oil pressure gauge.

[jd52cranbrook]

If this engine is rebuilt, I would think the 10/40 is unnecessary, and would raise the pressure. 5/30 or 10/30 seems more appropriate.

Other than that,,,,,, drive it.

Edited June 15, 2010 by jd52cranbrook

[Don Coatney]

Best I can find in my manual is 40-60lbs above 30mph--another section said 40-50lbs at 40-50mph-----could not find specs for idle pressure----it appears I might be on the high side for idle. Again new pump is higher pressure and volume, this probably changed the stats----I will call VPW for specs on pump...............Lee

My question was where did you buy the pump but from this posting I assume VPW. My next question is why did you buy a souped up pump? Do you plan on winding this engine above 5000 RPM's? If so did you cross drill the crankshaft for increased oil volume?

It has not gone far --3-4 miles but I have let it get to operating temp and idle time has been 20 minutes when I was checking it out. Pressure stays the same. Would air in the lines be a problem?

As has been mentioned air in the line is required for a steady reading. Twenty minutes of running the engine at idle will not bring the engine up to full operating temperature. Twenty or more miles of driving (where the engine is actually doing some work) will bring the engine and oil up to operating temperature. Suggest you make sure your AAA card is current and hit the road for a real test. Report back after a 100+ mile trip.

[BeBop138]

Don, these were the only new pumps avaliable thru them at the time. Everybody said because of the close tolerances these pumps have to have, I just decided new was the route to go V.S. trying to rebuild one. I could change the oil if needed to see what happens----my only concern is that I am not damaging anything. I always thought higher pressure was a good thing.......Lee

[Don Coatney]

Don, these were the only new pumps avaliable thru them at the time. Everybody said because of the close tolerances these pumps have to have, I just decided new was the route to go V.S. trying to rebuild one. I could change the oil if needed to see what happens----my only concern is that I am not damaging anything. I always thought higher pressure was a good thing.......Lee

As I said drive 100+ miles and report back.