oil pump selection questions?

[wrench87]

i hear different opinions on high volume oil pumps, some people say they are used on race motors when they are using loose clearances, they use horse power and put stress on the drive and cam gear. now what about a high pressure oil pump do they rob horse power or put stress on the oil pump drives?. i am trying to decide on wich pump to use in my 390 stroker i will be using a baffled oil pan also. any thoughts on this subject?

[speed220mph]

Use a standard pump with standard clearances. You'll be glad you did. All an oil pump has to do is provide 10 psi per 1,000 rpm, which is easily obtainable with standard bearing clearances. More volume means lost power to the flywheel and extra load on the oil pump/distributor drive gear. So don't fall into the trap of using a high-volume pump.

[RICK LAKE]

wrench 87 I use a HVHP oil pump in my car with a harden oil pump shaft. It also has a 100 psi spring in the pump, not 80. Something to think about, how many motors have you seen blow up from high oil pressure??? We don't know what clearances are being used on this motor?? If blueprinted from old school, .003" mains and rods. You better have a HVHP for this kind of looseness. I run a shelby block with under .002" on rods, BBC ones and .0022 on mains. This motor expands about .001" when hot. I just replaced the crank rods and pistons with a stroker kit from Barry R. Kit works great, bearing clearances where on the money for what I run. FE bearing are small and narrow for the rods in FE motors. I want all the pressure and oil I can get to this area to float the rods and bearings off the crank surface. I have raced the motor for 7 years and the distrib gear is just fine. All you have to do is make sure that oil is getting to this location and lube the 2 gears. A peroiler would be another thing to add to your motor. This will stop dry starting and bearing wear. I have a 3 quart accusump for this. Works great. When cold I don't race the motor, I am getting about 125 psi when cold, even with the 100 psi spring. Let the oil warm up alittle before moving the car or changing engine speeds. Just a thought that I do. I am going to a drysump system on my next motor, 498 shelby and run the same pressures. I have limiters in the heads to keep most of the oil down stairs. Rick L.

[jwd]

Originally Posted by speed220mph

Use a standard pump with standard clearances. You'll be glad you did. All an oil pump has to do is provide 10 psi per 1,000 rpm, which is easily obtainable with standard bearing clearances. More volume means lost power to the flywheel and extra load on the oil pump/distributor drive gear. So don't fall into the trap of using a high-volume pump.

This is VERY good advice. Follow it and you won't have any problems.

[RedCSX1]

Contact Doug at Precision Oil Pumps in Clovis CA. 559-960-0460

[wrench87]

i noticed that all the precision oil pumps are high volume?

[scootter]

I had an HV pump in my motor before it was rebuilt. Both the engine builder and Ford Racing said to use it for a paper weight and go back to a standard oil pump.
Scott

[wrench87]

scooter do you have a small block or a big block?, i have a standard melling in my 342 engine wich works fine but this is for a 390 stroker.

[RedCSX1]

Originally Posted by wrench87

i noticed that all the precision oil pumps are high volume?

He will blue print the pump to what you want.

[J Persons]

I have the HV Precision Oil Pump in my small block. The pressure is adjustable by removing the oil pickup and turning the spring stop. Precision Oil Pumps sets them up to run approximately 85 to 90 psi hot @ 1000RPM, standard clearances and 10w30 Mobil 1 on my engine. If you don't want to run that much pressure, simply turn it down. One revolution of the spring stop CCW, is about a 8 or 9 PSI reduction. The Teflon inner coating on the gearotor and housing is a nice touch and makes the rotor feel like it runs in butter. IMO, well worth the money.

On a related note, I was using a Canton rear sump road race pan with all the trap doors, baffles, etc, designed for a Mustang. Under high speed braking, I was loosing oil pressure, to the point that I could hear the lifters tick. The only thing I can think of was the oil was moving to the front of the pan, and when the pump sucked the baffled area dry, it started pulling air, because the G force was keeping the oil in the front of the sump. I recently bought an Armando's front sump pan in an effort to cure this. Hope to have it installed soon and tested. This wasn't a problem until I installed the Wilwood 6/4 piston brakes.

[xlr8or]

Originally Posted by RedCSX1

Contact Doug at Precision Oil Pumps in Clovis CA. 559-960-0460

Ditto what Morgan said. Doug can set it up any way you want.

[sideoiler10]

Which would you rather do...loose a few ponies or loose a rod through the block?

[RICK LAKE]

Sideoiler 10 You will find that there some people that would rather have the rods windows than wearing out gears on the distributor. They make a composite gear that is promised to not wear out. I have one, but didn't put it on my distributor in the car because there was not wear to the teeth from the setup in the car yet. It's all bout getting oil to the places it needs to go. Rick L. Ps I have changed to a roller cam and will watch for a wear problem. Still running the MSD gear on the bottom.

[scootter]

I have a stroked big block 514.
Scott