high volume oil pump vs stock

[Greasey Harley]

I am rebuilding an '87 5.7/350 for my 79 k10.
mild build:
flat top pistons 9.5:1, marine cam, TBI swirl port heads, HEI, Q-jet. This motor will probably never see 5K rpm's. It's a truck motor, built for low range torque.

I realize that a standard oil pump will deliver all the oil this motor ever needs.

Thing is though, ...the oil pressure drop that sbc's have at idle DRIVES ME NUTS!!!!
I know it shouldn't, but it does.

I like to look at the gauge and see good, steady oil pressure all the time, hot or cold, idle or WOT.

So, my question is:
(With the exception of the extra power it takes to turn a high volume pump), Is there REALLY any drawback to a using high volume pump on a stock build?

[geezer#99]

High volume pump won’t change your hot idle number. Higher pressure might.

[SunSoaked]

Higher idle,thicker oil... accurate guage.

[kwmech]

Just put a stock 396 pump on it, it'll bring up volume and pressure

[Captainfab]

IMO a HV oil pump should be accompanied by a larger capacity oil pan. Although if you are not turning much in the way of rpm's, engine oil capacity should not be an issue. While a HV oil pump may bump your psi a little, you can also achieve higher pressure with a standard oil pump by either changing the relief spring or adding a small washer or two between the pin and the spring. Also I believe you can purchase a standard volume pump with a high pressure spring already installed.

[Greasey Harley]

I have been doing some research. Forgive me if I am mistaken, the way I understand it is:

at lower RPM's pressure is a direct relationship between how much oil the pump is moving, and the resistance of the bearings, tolerances and oil passages. Basically, if you push more oil thru the same orifice, the pressure increases.

High volume pumps have bigger gears, and move more oil at all Rpm's

Once the pressure gets to a certain point, the bypass spring regulates the maximum pressure by opening the bypass, and keeping the pressure from going too high.

Standard pressure springs regulate Max pressure at 55-65psi, and high pressure springs regulate Max pressure around 75-80 psi.
Until the bypass opens, the oil pressure is decided by how much oil is being pushed through the motor.

----> High Volume pump = higher oil pressure lower Rpm's (until the bypass opens)

----> High Pressure pump = Higher Max oil pressure

----> HV-HP Pump makes pressure faster and has a higher Max pressure.

...at least that's the way I understand it after a whole bunch of reading, and talking to a couple of good engine builders.

[sweetk30]

10psi per 1k rpm i have always been told .

high volume can suck a pan dry .

guy i know who built motors for over 20 years said he hardly ever used a hv or hp pump on sbc or bbc builds .

[b454rat]

I've used high volume pumps in every motor that ive changed the pump on. Both small block and big block, stock, mild or hot. Talked with many engine builders, some that built my motors. If there was something that they didn't agree with, they didn't do it. I've also used stock pans, and never ran out of oil. if you have a motor that has some miles, it will ensure your getting oil where it needs to be.

[homemade87]

I also used high volume low pressure oil pumps in every first gen motor I had ever built . Any street engine is not a concern with sucking the pan dry . Only with high rpm long term runs like road racing .

Never a problem here . I drove mine stuff hard at times . Thats what I built it for .

[Chevyrestorerman]

Melling has what they call "Shark Tooth Pumps” for the Chevy engines. These type of oil pumps feature helical cut gears instead of the usual straight cut spur gears. Big difference when you pre-oil your engine prior to break in, in the terms of what it takes to turn the oil pump once its primed vs the other type of oil pumps

[Tom]

Originally Posted by Greasey Harley

Thing is though, ...the oil pressure drop that sbc's have at idle DRIVES ME NUTS!!!!
I know it shouldn't, but it does.

I like to look at the gauge and see good, steady oil pressure all the time, hot or cold, idle or WOT.

What you want makes no sense. Lower rpm means less pump revs, less flow and so less pressure. Then theres the whole less stress on engine requiring less oil pressure. You can't have 60psi at all times, nor should you want it.

[GASoline71]

HV and high pressure pumps also wear uot your distributor gear faster...

Gary

[crazy longhorn]

Originally Posted by Captainfab

IMO a HV oil pump should be accompanied by a larger capacity oil pan. Although if you are not turning much in the way of rpm's, engine oil capacity should not be an issue. While a HV oil pump may bump your psi a little, you can also achieve higher pressure with a standard oil pump by either changing the relief spring or adding a small washer or two between the pin and the spring. Also I believe you can purchase a standard volume pump with a high pressure spring already installed.

I totally agree with Captainfab....to bring up another poster,,,(10 psi per 1000 rpms0 is right on! I have never run the pan dry, but I usually run a 6 or 7 Q pan....Longhorn

[cla511]

I like to look at the gauge and see good, steady oil pressure all the time, hot or cold, idle or WOT.

Newer vehicles have buffered gauges. They read in the middle for a normal operating range of pressures. Many temp gauges do the same thing. It keeps people from complaining. So basically they have turned the idiot light into an idiot gauge.

So what you are asking for in our stuff will not happen.