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which oil pump for a 406? high volume or high pressure?

7K views 22 replies 16 participants last post by  67 Deuce 4 Me 
#1 ·
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?
 
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#4 ·
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.
 
#6 ·
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.
 
#7 ·
bracketeer said:
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.
 
#10 ·
406 sbc

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. :pimp:
 
#11 ·
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.
 
#12 ·
oil pump

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
 
#13 ·
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.
 
#14 ·
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?
 
#15 ·
406 ss monte said:
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?

High pressure is good for maintaining oil film in the bearings when there is very high cylinder pressures forcing the rods into the crank, pushing the crank into the main bearings, cam into cam bearings (strong valve springs), etc. It also makes for more oil pushing through and out of the bearings when not under high load conditions.

A high volume pump is generally a crutch for loose bearing clearances.
If the bearing clearances are such that the extra oil cannot be pushed through, the extra oil ups the pressure to the bypass spring limit and then will bypass.

Many people install HV pumps in SBC since the low rpm oil pressure is so low because of the excessive lifter bore clearance.

High volume pumps "sucking the pan dry" is a myth perpetuated by the poor drain back characteristics of the drain back system. It happens, but it is not the fault of the oil pump.

Generally speaking, a correctly built engine needs only a standard volume pump. Installing a high volume pump AND/or high pressure spring in there is OK since all it will do is bypass the excess anyway.

Also, contary to popular belief, high volume or high pressure pumps do NOT take significantly more horsepower to drive them. If they did we couldn't turn the oil pump 4000 engine rpm with cold oil using 3/8 hp electric drill, could we????

check out www.readershotrods.com drag cars/georges drag strip
 
#16 ·
what if i was planning on using a 250 shot of nitrous latter on? the extra oil pressure of the high pressure pump would be ok then wouldn't it?
i also have the oil filter bypass plugged so all the oil goes through the oil filter, will a high pressure pump blow out the oil filter? i've heard of this before, but have never seen it first hand.
 
#17 ·
406 ss monte said:
what if i was planning on using a 250 shot of nitrous latter on? the extra oil pressure of the high pressure pump would be ok then wouldn't it?
i also have the oil filter bypass plugged so all the oil goes through the oil filter, will a high pressure pump blow out the oil filter? i've heard of this before, but have never seen it first hand.
Heard of it. Never seen it.

Stock filter cans should stand 150 plus. Race filters more.

The high oil pressure bypass spring is usually 80 psi. Have a good gauge.

I am not crazy about the filter bypass being blocked.

Some people use dual remote oil filters. They pass the same volume of oil at half the pressure drop.
 
#19 ·
406 ss monte said:
what if i was planning on using a 250 shot of nitrous latter on? the extra oil pressure of the high pressure pump would be ok then wouldn't it?
i also have the oil filter bypass plugged so all the oil goes through the oil filter, will a high pressure pump blow out the oil filter? i've heard of this before, but have never seen it first hand.
On 99% percent of the street pefromance engines we build we have been uing the 10552 oil pump which has 10% more volume and we line hone all our blocks so we know what we have for main beaing clearance and we machine the big end of the rods for proper clearance as we shoot for .002 to .0025 and one area that is over looked buy many machine shops is cam bearing clearace as we check the housing bores for size and we do find many over the high limit so from there we blue print bore them to the correct spec and on the engine we have built we have never had any oil pressure issues so far.

On ALL the SBC we build we plugged the bypass and use a NAPA 1061 or WIX 51061 for 20 years or so and no problems so far and as far as oil pumps go the later M-55, M-55A, M-55HV are now made using a lighter casting or body and on performance engines we have had a lot of calls and emails concerning pump breakage and this is more common on chassis using solid motor mounts and there pumps have powdered metal gears here is good link to view http://forums.godragracing.com/viewtopic.php?t=36095

Here is a link to the new M-Select pumps http://www.melling.com/select/oil_pumps_gm_chevy_small_block.asp

Hope this will help some of you out.
 
#20 ·
the melling 10552 is the best choice i think. ive used the m55a pump which is a good pump around 78psi but the stock m55 run about 55psi to 70 psi. melling says high volume is needed where oil coolers are used. but the bluprinted 10552 and 10555 are the better choice mainly because of the bolt on pickup, thats my opinion :)
 
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