[406 ss monte]

i've always heard a high volume oil pumps make the same pressure as stock pumps, but all the stock pumps i've used have made around 45 psi & all the high volume pumps i've used had about 65-70 psi. how much more pressure will a high pressure pump make?
i'm running a 7 quart pan so sucking it dry isn't an issue, which i've ran high volume pumps with stock pans & never had a problem sucking it dry.
what would a high volume pump be used best for? what about a high pressure?
heres my combo to show what i'm running.

406 sbc
3.75" 4340 crank
5.7" h beam 4340 rods
srp forged flat tops
10.68 to 1 compression
ultradyne solid lift cam ( 250-260 @ .050" .530"-.550" lift 108 l/s)
dart pro-1 215cc heads
victor jr intake
750 holley double pumper
mallory ignition
3,500 stall
350 turbo
3.89 gears
255-60-15 tires
85 ss monte carlo 3,500 lbs.

i'll be turning it probably no more than 6,500 rpm & maybe not even that high. which oil pump do i need? high volume, high pressure, or a high volume & high pressure pump?

[poncho62]

Go with the high volume...............Too much emphasis is put on oil pressure, especially in SB Chevys. The 7 qt pan is a great idea.

[302 Z28]

I agree, go with the high volume.

Vince

[MI2600]

I think that if I had to do it over again, I would have gone with a standard pump in my 406. I used the high volume and it's a real joy if you have to set the valves with the engine running. Oil everywhere.

[bracketeer]

High volume pump is a great idea if your putting that motor in your 4X4.

[matt_ramsey]

it's a real joy if you have to set the valves with the engine running. Oil everywhere.

or, if you're lucky like me, it hits your headers and you just get smoked out of your garage in about 5 seconds. If you can afford it most people recommend the Melling pump that is 10% higher volume than stock (their regular high-vol pump is like 25% higher volume). It's not THAT expensive for the 10%, but it's hard to pass up the deal on the 25% model for twenty some bucks, expecially when you've got the pan to handle it.

[406 ss monte]

Originally Posted by bracketeer

High volume pump is a great idea if your putting that motor in your 4X4.

what would be the difference in a 4x4 & a car? it's going in a 85 ss monte carlo.
i use solid lift cams, so i don't set the lash with the engine running. i didn't when i run hydraulic cams. if you set one lobe at a time while it's on the stand or in the car, you can avoid getting oil all over everything.

[Jmark]

Personally, neither one, providing all your clearances are within spec. I used the M55 in my latest 350 and my sons killer 406. Both of us have 60+ cold and run at 50 on the highway hot. Just my opinion.

Mark

[NAIRB]

I would use a blue printed stock pump.

[85Sierra]

i use a standard volume melling in my 406 and it will sit at 80psi cold and wont dip lower than 20 when hot (210 degrees +)

[MARK TINNELLY]

I have a 406 in my 87 monte aerocoupe with roller cam, lifters
and rockers, we went with the melling pump and the oil pressure never drops below the mid 20's when hot,. that it a great idea to go with the bigger pan, wish i had thought of that, which one did you use?
Just be careful that you have your fan shroud in place and fit a heavy duty clutch fan to make sure she doesnt run hot.

[xntrik]

I am with NAIRB in # 9.

Maximum oil pressure is regulated by the pressure bypass spring. Minimum oil pressure is controlled by the oil viscosity and the clearances in the engine. A large disparity between cool and hot oil pressures indicates poor clearances/ oil delivery problems.

The bypass spring settings has nothing to do with pump capacity.

A HV pump might make more pressure below the spring setting if the engine clearances are excessive.

A high volume pump will not suck a pan dry just because it is a HV pump. There is an excessive top end oil delivery problem or an insufficient oil return problem. Using a big pan to prevent starvation is a crutch that still allows excessive oil build up in the top end.

We discovered years ago that a race engine with top end and valley screens would flood the top end or suck the pan. Removing the drain back screens cured the problem.

Old tales die with great difficulty.

Now let's tackle the one about the excessive horsepower drain of a HV oil pump.... lol.

[k-star]

Well i think there are some things that we need to look at first....

If it's more then a 3.750 ( 3.875 and up) stroke crank i will use a hv pump. If it's a 3.750 that is cross drilled i will use a hv pump. On the smaller stroke engines with good bearing clearances i will run a stock pump.... If it's a non-cross drilled 3.750 stroke and your bearing clearances are .0025 mains and .002 on the rods i would run a stock oil pump....

If you decide on the hv pump make sure you set the pick up the correct distance off the bottom of the pan and then weld some typ of stand off on-to the pick up so the pan cannot get sucked up against the pick up.....


Keith

[Blazin72]

Gear height is what determines volume in an oil pump. The taller the gears inside the pump are the more oil the pump is going to move in each revolution versus one with shorter gears. As far as the pressure is concerned, like Xntrik said, there is a relief spring in the pump that can be changed out. Any of the pumps Ive used came with a second spring in the box so you have the choice to run either high or low pressure.

[406 ss monte]

the rods & main bearing clearance was set by the machine shop.

i guess what i should have asked was in what type of motor should you use a high volume oil pump, & in what type should you use a high pressure pump?
most people say a high volume is great in a 4x4, WHY? why not a high pressure?