Hi volume oil pump vs standard volume pump

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As a guess.. maybe 1 HP. Easy to figure out why:
  • The torque/HP needed to turn a positive displacement pump is in proportion to the size. The HV for the SBM has only 20% taller gears than the standard. (That is not a very big increase for an HV, whereas some other HV pumps are 40% taller (and maybe more) than their standard counterparts.)
  • So the pump power for the HV is gonna be 20% more pretty much all across all RPM's.
  • To see how this works, let's theorize that the difference was 5 HP at high RPM's between HV and standard. For that to be true, then the HV would be pulling 30 HP while the standard would pull 25 HP, so that the 20% difference would be consistent with the 5 HP difference.
  • You are not going to be putting 25-30 HP into this size of pump, even at high RPM's LOL.
6 vs 5 HP is plausible. Example computations shows a few HP being drawn by a pump of this size..... though it is hard (for me) to assess the effects of oil viscosity.
 
And I can't see any reason for extra windage at higher RPM's for an HV versus standard pump. There is no more oil flow into the engine. Either pump at high RPM's flows far more than the flow requirements of the engine; the flow into the engine will be limited by the pressure (which is set at high RPM's by the relief spring, not the pump impeller height) and the engines restrictions. You would get MORE flow into the engine at high RPM's, and more windage, by using as standard pump with the higher pressure relief spring than an HV pump with the low pressure relief spring.
 
Seriously, if that's how you think it works I'd suggest you need to do a lot more research into the subject.
 
Same 340, went from 72 hv to m72.....no pressure difference on the gauge what so ever.
I took the advice to ditch it, that it ate almost 10hp by 6000 rpm. I dont bother with hv pumps anymore.

I like the front main tighter than the rest, I like full groove mains, m72 pump, milodon pickup and deep pan, I like to use a windage tray 'even with the deep sump' they still help and if you use a thick milodon version... they act like a motor blanket as in they'll save your 350.00 oil pan from holes if you lose a piston or shut it off soon enough with a rod....just ask how I know.
 
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moper said:
Seriously, if that's how you think it works I'd suggest you need to do a lot more research into the subject.
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Goodness.... I'd be happy to hear why it does not do as described. (I think can take it.) People get confused at the name high volume; that describes only the pump. The system's flow volume behavior is not just the pump; it is the pump, the relief spring, and the system's outlets.

I'd suggest starting with an understanding of the behavior of positive displacement pumps; that has a specific meaning. They will try to push an amount of fluid directly proportional to speed regardless of the back pressure. If the amount being pumped exceeds the flow that the system downstream will accept, pressure increases until:
  • the rest of the system does accept that flow
  • the pressure goes to a level where something like a relief valve allows the flow to go elsewhere (back to the pump intake in this case)
  • the pump internal leakages get excessive
In the case of these 2 pumps, the oiling system accepts the flow dependent on the pressure at the output of the pump. If the pump has a lower pressure output due to a lower pressure relief spring, then less oil will flow into the system and less will be available to become windage; that was the point. Both of these pumps will put out enough flow to drive the pressure up to the relief spring pressure at higher RPM's, if they are in good shape and you don't have some excess clearance downstream. The HV will just get there at a lower RPM.

MOPAROFFICIAL said:
Same 340, went from 72 hv to m72.....no pressure difference on the gauge what so ever.
I took the advice to ditch it, that it ate almost 10hp by 6000 rpm. I dont bother with hv pumps anymore.
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Not sure you meant to say one thing or another on the matter, but the first sentence is what I am trying to explain .... both pumps will push out adequate volume to trip the pressure relief at sufficiently RPM's. The only place that an HV pump will show higher pressures is at lower operating RPM's where the output pressure is below the level of the relief spring.
 
Dang, i am sure getting an education on this. I think with a stock built 318 and some bolt ons like a cam, exhausts and intake the stock volume pump is probably sufficient.
 
For what it's worth,
I've been struggling to the get the (baffled) oilpan removed from my 360 engine in the car for almost a day (baffles, headers, steeringlinkage, K-member issues), removing the windagetray and oilpump, only to find out the pump was already an HV-pump!
I should've made better notes when I put this engine together.
So the cause of my low-pressure readings has now really shifted to elsewhere in the engine (first suspect: the lifter oilbands and lifterbore camfer).

I opened up the oilpump and found nothing but goodness inside. I will still install a new oilpump and fix the oilpan's baffles which got bent a bit by the removal of the pan.
 
moparmat2000 said:
Dang, i am sure getting an education on this. I think with a stock built 318 and some bolt ons like a cam, exhausts and intake the stock volume pump is probably sufficient.
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Honestly, I'd agree. I like the HV just because it will give a bit better pressures at lower RPM's; I don't run at extended high RPM's so any added (trivial) power loss is a non-issue for my uses. IMHO, a GOOD pump with well in-spec clearances is the most important thing; and, as noted the 'HV' aspect of the SBM HV pump is not nearly as much 'HV' as in some engine designs.
 
BigBlockMopar said:
For what it's worth,
I've been struggling to the get the (baffled) oilpan removed from my 360 engine in the car for almost a day (baffles, headers, steeringlinkage, K-member issues), removing the windagetray and oilpump, only to find out the pump was already an HV-pump!
I should've made better notes when I put this engine together.
So the cause of my low-pressure readings has now really shifted to elsewhere in the engine (first suspect: the lifter oilbands and lifterbore camfer).

I opened up the oilpump and found nothing but goodness inside. I will still install a new oilpump and fix the oilpan's baffles which got bent a bit by the removal of the pan.
Click to expand...
BTW, check out the relief spring area of the pump too. Any imperfection there could be causing problems.
 
RustyRatRod said:
Ok, so what's the high volume oil pump cost horse power wise? 10HP? 15HP? And at what RPM? 7500? I will never build another engine with a stock volume pump. Ever. Yall do what you want.
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Last time this subject popped up...as it does about every 2 weeks....I search with google and found a car craft dyno section where they used a sb chevy....only thing changed was oil pump....the HV pumped used 4 hp more then the standard pump.....they found more HP in changing viscosity of the oi......But i agree with what you said...Use what you want....I do....
 
moper said:
I can tell the difference on a cold engine pre-oiling with my cordless drill. Plus there were enough breakages or concerned over it that Mopar developed the heavier drive shaft for them. So yes, there will be power taken by the pump and to probably similar extent, the additional windage created by excessive oil draining back and flying off parts. Just my observations on the subject. I'm not going to worry about quantifying beyond that.
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The hardened oil pump drive isn't a Mopar only thing. The parts catalog lists a hardened oil pump drive for use with HV pumps in every older domestic make. That still doesn't mean you'd ever feel the difference in a warmed up engine a 5000 RPM and up. Its just not a place where "I" would look for "extra" power. I don't want to give up anything in the oiling department.

Opinions vary and that's a good thing. This is a good discussion.
 
nm9stheham said:
BTW, check out the relief spring area of the pump too. Any imperfection there could be causing problems.
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Yes, I will.
I think I've already noticed something when looking back at the few pics I took, but it could also just be a machining/casting difference between the 2 oilpumps I have.
 
nm9stheham said:
Honestly, I'd agree. I like the HV just because it will give a bit better pressures at lower RPM's; I don't run at extended high RPM's so any added (trivial) power loss is a non-issue for my uses. IMHO, a GOOD pump with well in-spec clearances is the most important thing; and, as noted the 'HV' aspect of the SBM HV pump is not nearly as much 'HV' as in some engine designs.
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This is one of the reasons I went with the HV pump and increased oiling to the top end; so I could parade the dang car with a minimum water temp of 207*F,at 4 mph, which with my 3.55gears is 550rpm. (Just try that trick with a manual trans, a750DP, and a 292/292/108 cam.) I wanted my expensive aluminum rocker arms to live.
The thing about a street car is; I'll guess 95% or more of a streeter's life is spent well below 4000rpm, yet we build them to go ~6000. Every system has to be re-evaluated for it's intended usage.
Ask me if I care about 4hp at 6000 rpm, when my tires are spinning? Ask me if I care about 20/30 hp at 5500 when the tires are still spinning. I still don't care. What I do care about is my rocker arms, and they currently have over 100,000 miles on them, so I think it's working. I traded away my 292/292/108 for a 270/276/110 and was very happy about the deal. And that 270 cam about halved my fuel usage. Double-win.
 
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AJ/FormS said:
This is one of the reasons I went with it and increased oiling to the top end, so I could parade the dang car with a minimum water temp of 207*F,at 4 mph, which with my gears is 550rpm. (Just try that trick with a manual trans, a750DP, and a 292/292/108 cam.) I wanted my expensive aluminum rocker arms to live.
The thing about a street car is; I'll guess 95% or more of a streeter's life is spent well below 4000rpm, yet we build them to go ~6000. Every system has to be re-evaluated for it's intended usage.
Ask me if I care about 4hp at 6000 rpm, when my tires are spinning? Ask me if I care about 20/30 hp at 5500; the tires are still spinning, and I still don't care.I care about my rocker arms and they currently have over 100,000 miles on them, so I think it's working. I traded away my 292/292/108 for a 270/276/110 and was very happy about the deal. And that 270 cam about halved my fuel usage. Double-win.
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What make is your 270/276/110 and what lift?
 
Jadaharabi said:
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What make is your 270/276/110/53*overlap and what lift?
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It dropped lobes so it's been gone since 2004. It was a Hughes HE2430AL, now obsolete. Specs were IIRC, 223/230 @.050 and with my 1.6 arms .538/.549 lifts; yeah that's correct. She ran an Scr of 10.9 with aluminum heads and cylinder pressures of over 180 on my MAC gauge.
I replaced it with another (also now obsolete) Hughes HE3038AL; 276/286/110/61*overlap, and 230/[email protected] with lifts of .549/[email protected]. TTIs and full-length dual 3inchers.
The first cam was the Mopar 292/292/108 and that one I ran at 11.3Scr and .028Q.. The later ones are at .034Q.. The .028 gasket was not up for it, so I switched to the .039FellPros and brought the pistons up to .005above deck. So I lost a tad of Scr, but gained pressure.
 
Just another source of info on these pumps from Melling:
Technical - Melling

The first entry in their section on " Common Misconceptions on Oil Systems" (with the answer following the colon) is:

Oil pumps produce pressure: Oil pumps produce flow and the resistance to that flow produces pressure. The pressure relief valve limits the maximum pressure but does not do anything until the pressure has reached that point.

(Emphasis is mine...)

They did make one editorial mistake on that page.... see if you can spot it.
 
nm9stheham said:
Just another source of info on these pumps from Melling:
Technical - Melling

The first entry in their section on " Common Misconceptions on Oil Systems" (with the answer following the colon) is:

Oil pumps produce pressure: Oil pumps produce flow and the resistance to that flow produces pressure. The pressure relief valve limits the maximum pressure but does not do anything until the pressure has reached that point.

(Emphasis is mine...)

They did make one editorial mistake on that page.... see if you can spot it.
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I am guessing, the first sentence should read oil pumps produce flow ?
 
RustyRatRod said:
I will never build another engine with a stock volume pump. Ever. Yall do what you want.
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Same here. But think what a fool I was with the HV pump and the stock 4 qt pan on the 451. It only made 787 HP at 75psi with the hi volume pump. We might have set the world on fire with a 7 qt pan and a standard pump.
 
nm9stheham said:
Just another source of info on these pumps from Melling:
Technical - Melling

The first entry in their section on " Common Misconceptions on Oil Systems" (with the answer following the colon) is:

Oil pumps produce pressure: Oil pumps produce flow and the resistance to that flow produces pressure. The pressure relief valve limits the maximum pressure but does not do anything until the pressure has reached that point.

(Emphasis is mine...)

They did make one editorial mistake on that page.... see if you can spot it.
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I see several mistakes. A lot of words left out an incomplete sentences.
In this statement I think they use the word new in place of the word old.

The valve or slots are there to allow cold thick oil into the pump. If you use thick oil with [new] screens, you a good chance of starving the engine of oil and ruining it.

They say that there is a varnish on the old .screen that is restricting the passage of oil into the tube. A new tube would not have that restriction.
Notice they left the word "have" out of the sentence making it seem like some idiot wrote it "you a good chance"

Now I understand the reason for the hole in the middle of the stock pickup screen.
Some good info but poorly written.
 
I run a hi volume pump in my 340 with a moroso 8 qt. pan and their rectangular screen pickup. I would not run a hi volume pump in some other makes with a stock pan. my friends 327 with a big cam and a stock pan and a hi volume pump and 4.88 gears on a 1 mile blast down route 18 showed zero pressure on the gauge. we pulled over and everything looked good. the pickup did not fall out. we waited a moment and drove away. later he went 12.5 at epping
 
Marcohotrod said:
I run a hi volume pump in my 340 with a moroso 8 qt. pan and their rectangular screen pickup. I would not run a hi volume pump in some other makes with a stock pan. my friends 327 with a big cam and a stock pan and a hi volume pump and 4.88 gears on a 1 mile blast down route 18 showed zero pressure on the gauge. we pulled over and everything looked good. the pickup did not fall out. we waited a moment and drove away. later he went 12.5 at epping
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4.88 gears at the end of a mile. What was the mph? what was the rpm about 12000?
 
I did not say his foot was to the floor. about 6500 with 26" tires and 4.88 gears for a while = about 103 mph, more rpm cuz it was a high stall auto. 327 chevy, stock pan, high volume pump sucked pan dry. later he did 12.5 at 108 mph at 6900
 
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Sbc oils to 10,000 rpm, of course it sucked the pan dry.
I never sucked the pan dry when I ran the hv with the stock 340 pan and tray turning 7,000.

In some areas, sbc and sbm are apples to oranges...
 
There are things to consider like oil system/galley mods, but the end leakage is still the final say.

It wont hurt anything to run a hv, so rock out with your c*** out... but you are just heating the oil more and giving up a few at the top.
Maybe a big block that spins no.6 rod bearings a hair over 7000 could benefit, that I understand... but if this pertained to small blocks, that's irrelevant to this post.

Let me be clear,btw.. not talking about stock relief OEM 55 psi vs hv.

The m72 is all you need.imo
 
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