Hi volume oil pump vs standard volume pump

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Marcohotrod said:
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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I raced a 66 chevell 427 4speed with my 72 duster, 12.5, 340 4speed with 3.91 gears. We topped out side by side right at 150. I was turning 7500 an never lost oil pressure.
Needless to say it hurt his big blocks feelings.
I had a mechanical linkage 6 pac on my 340at the time.
 
My street combo hits 66mph at 7000 in first-over. And I used to buzz her up there many times every time I took her out. And she has endured that since 1999..... with Milodon HV pump, pick-up,roadrace-pan and tray. Not bragging, just offering. Also, she used to spend a lot of time above 5500, cuz that's just my style, and cuz she lived, but mostly cuz she just sounds so good up there. Again, just offering data.
Well, she doesn't just hit 7000 at 66. I leave the line and nail it. She revs to 7000 and I keep her there for IDK 5 or 6 seconds until 65 and then shut down,usually. One time I went to the track, I kept her singing between 7000 and 7200 to 93 mph@7.92 seconds.Nothing broke and I drove it home. Yahoo.
Just how much oil can one of these pumps,pump, in 7.92 seconds at 7000, the whole way?
 
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AJ/FormS said:
My street combo hits 66mph at 7000 in first-over. And I used to buzz her up there many times every time I took her out. And she has endured that since 1999..... with Milodon HV pump, pick-up,roadrace-pan and tray. Not bragging, just offering. Also, she used to spend a lot of time above 5500, cuz that's just my style, and cuz she lived, but mostly cuz she just sounds so good up there. Again, just offering data.
Well, she doesn't just hit 7000 at 66. I leave the line and nail it. She revs to 7000 and I keep her there for IDK 5 or 6 seconds until 65 and then shut down,usually. One time I went to the track, I kept her singing between 7000 and 7200 to 93 mph@7.92 seconds.Nothing broke and I drove it home. Yahoo.
Just how much oil can one of these pumps,pump, in 7.92 seconds at 7000, the whole way?
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Tnx for the data point AJ.

The pertinent answer is 'waaay more than a decently clearanced engine can accept'. The real question is not how much the pumps will pump at those RPM's but how much the engine will accept at the resulting pressure into the engine? Both of these pumps will put out more than enough flow at those RPM's to force the pressure to rise to trip either the 55 or 72 psi relief valves (assuming both pump and engine are in decent shape). At that point, whatever the engine will accept at those output pressures is the flow into the engine. If that intake flow rate is less than the return flow rate, then the pan ought to continue to have adequate oil in it.

Of course, that is ignoring any tilt or slosh of the oil in the pan away from the pickup; keeping the pickup awash in oil is a factor that tends to be unknown in anecdotal reports.
 
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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Yes, my 318 has all the bolt ons that you are suggesting. My oil pressure is between 60 and 70 PSI on start up and 25 PSI at warm idle.

This is on an engine that the bottom end hasn't been touched (to my knowledge). 84,000 on the clock.
 
C130 Chief said:
The pressure is controlled by the bypass valve spring regardless of pump volume. Pump output is linear with RPM so as the pump spins faster, it pumps more oil. As the pump tries to stuff more oil through the engine, the pressure will rise as the engine can only consume so much oil. Once the pressure rises to the point the bypass opens, any additional oil is just returned to the pan. A bigger pump will just cause the bypass valve to open at a lower RPM and then just pump more oil back to the pan. If the bearing clearances are within factory specs, a standard volume pump will open the bypass well before 3000 RPM. The larger pump offers no real advantage. If you use a stronger spring in the bypass valve, the oil pressure will be higher before it begins to dump back into the pan. Higher pressure does not mean more oil is going anywhere, sometimes the opposite. Higher pressure WILL increase the load on the intermediate shaft, cam and timing chain as well as requiring more power to operate.

The short answer is the stock oil pump is just fine for most applications with normal bearing clearances.

The old warning about a high volume pump sucking the pan dry at high RPM is not typically the case. Too much oil to the valvetrain is what causes that.
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Tell me how the oil is bypassed to the pan. Where does that happen on the pump. I see this statement all the time and as far as I know that is not correct.
 
70aarcuda said:
you are saying that all 5 qts of oil are on top of the heads?......nothing is draining back....BS.....327 chevy..>>LOL....does not have the open camshaft valley like a small block dodge...probably the pickup fell out of the oil pump like most 327 do...
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Lol lol good answer.
 
BigBlockMopar said:
Yes, the installed pump is/was new.
The oilpressure when cold starts out nicely at some 55-60 psi in neutral and 30+ in Drive.
But drops worryingly low when the oil starts to warm up to sub 20 and 15psi when 'warmed up'. But the engine temp never exceeds 160°F.
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What kind of hydraulic lifters, roller?
 
66fs said:
That does not look like there is enough open area to me. Looks like a suction loss.
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The thing to look at in that picture is the diameter difference between the threaded end and the tube. The tube diameter is much larger than stock. Has to work better imho.
 
Duane said:
What kind of hydraulic lifters, roller?
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Flat tappet hydraulic.
But I converted them to solids because a few of them were collapsing during the camshaft break-in.
This could possibly be related to the pressure loss but I didn't notice any low oilpressure on the engine stand. (But couldn't have the engine idle in drive ofcourse).

I just ordered a set of new solid, plain body lifters to replace the converted hydraulics soon.
 
Duane said:
The thing to look at in that picture is the diameter difference between the threaded end and the tube. The tube diameter is much larger than stock. Has to work better imho.
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I am looking at the number and size of holes in the "screen". Milodon looks different to me. The smallest restriction is the determining factor. See post #22. You would have to calculate the open area of the "screen" and the smallest diameter of the tube for me to feel better, especially with a Chinese knockoff.
 
66fs said:
I am looking at the number and size of holes in the "screen". Milodon looks different to me. The smallest restriction is the determining factor. See post #22. You would have to calculate the open area of the "screen" and the smallest diameter of the tube for me to feel better, especially with a Chinese knockoff.
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That is a perforated metal type screen.
I think they are better because less likely to clog. Agreed that a screen is more open, but the area here is way bigger than the pipe diameter. Flow is not the issue on the suction side with any pump. It's ability to generate suction is the primary concern. That's why suction side is always bigger than the output side. That pickup with the exception of the threaded area is bigger than stock everywhere including the screen.
The open area on the screen, even with the perforated metal type at 50% open is like 6x bigger every than the pipe. Not understanding your concerns.
 
Sorry, just thinking out loud. We would calculate everything and wanted at least 1 1/2 times the area of the smallest area of the tube. Perforated sheet sometimes has a very small open area. Not afraid of Milodon, they do their homework. Suction side is the limiting factor on even a stock pump. Chrysler used 1/2 pipe on the suction side of Hemi's. Milodon had single and dual pickups straight to the pan for Hemi's and Big blocks. Kit car small blocks had an available pump cover that allowed dual inlets. That pickup might be OK, I'm just a doubter.

McMaster-Carr
 
66fs said:
Sorry, just thinking out loud. We would calculate everything and wanted at least 1 1/2 times the area of the smallest area of the tube. Perforated sheet sometimes has a very small open area. Not afraid of Milodon, they do their homework. Suction side is the limiting factor on even a stock pump. Chrysler used 1/2 pipe on the suction side of Hemi's. Milodon had single and dual pickups straight to the pan for Hemi's and Big blocks. Kit car small blocks had an available pump cover that allowed dual inlets. That pickup might be OK, I'm just a doubter.

McMaster-Carr
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My current engine build has a milodon swinging pickup in it.
Just from memory it has a smaller screen inlet than the one on eBay.
But you are correct we could calculate it by math.
I have opened the threaded inlet on a hv pump to 1/2 pipe without issue.
 
66fs said:
Sorry, just thinking out loud. We would calculate everything and wanted at least 1 1/2 times the area of the smallest area of the tube. Perforated sheet sometimes has a very small open area. Not afraid of Milodon, they do their homework. Suction side is the limiting factor on even a stock pump. Chrysler used 1/2 pipe on the suction side of Hemi's. Milodon had single and dual pickups straight to the pan for Hemi's and Big blocks. Kit car small blocks had an available pump cover that allowed dual inlets. That pickup might be OK, I'm just a doubter.

McMaster-Carr
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I gotta say that the open area in the 'Zinc' brand pickup looks smaller than a Milodon. The 'typical' open %'s in perf screen are in the 25-40% range (that one sure does not look like 50%), and I'd expect that the effective flow are is gonna be reduced due to edge effects on the holes. At a SWAG of 25% flow area, the Zinc brand looks to be maybe 2x the outlet flow area....

Milodon 18314: Oil Pump Pickup Tube Small Block Chevy Street/Strip | JEGS
 
nm9stheham said:
I gotta say that the open area in the 'Zinc' brand pickup looks smaller than a Milodon. The 'typical' open %'s in perf screen are in the 25-40% range (that one sure does not look like 50%), and I'd expect that the effective flow are is gonna be reduced due to edge effects on the holes. At a SWAG of 25% flow area, the Zinc brand looks to be maybe 2x the outlet flow area....

Milodon 18314: Oil Pump Pickup Tube Small Block Chevy Street/Strip | JEGS
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Sorry I still do not get the problem you guys have with the eBay pickup. You are focusing on the screen and the size of the holes and not on the diameter of the tubing.
Look at the rectangular size of the inlet and tell me that all those holes regardless of size does not at least equal the area of the pickup tube diameter. Every hole in that screen can suck oil at any location.
In my previous post I mentioned my milodon swinging pickup.
Regardless of the size of the holes in the screen, it has a smaller size square opening than the eBay one. By square opening I mean the size of the frame that the screen fits into.
To my eyes the total area of the rectangular opening easily offsets the size of the holes in the screen. I also have an older milodon swinging pickup that has a bigger rectangular opening than my newer one, but with a mesh screen. How much flow threw that when it gets partially plugged up. The perforated metal type will probably never plug up. I think the eBay pickup recommendation was offered as an alternative to a larger diameter tube without much hassle, not as a direct comparison to the milodon which would be pan specific.
IMHO.
 
A screen's resistance to flow increases with the velocity of the flow. So it can't be judged on open area alone. At very low velocity the open area comparison is close enough. I'm not saying that particular perf has or doesn't have enough for the flow and viscosity, just saying its legit question.
 
Mattax said:
A screen's resistance to flow increases with the velocity of the flow. So it can't be judged on open area alone. At very low velocity the open area comparison is close enough. I'm not saying that particular perf has or doesn't have enough for the flow and viscosity, just saying its legit question.
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Agreed. Not sayin it's not a legitimate issue. Just sayin that Jadaharabi was trying to offer the op an improved pickup with a larger diameter for a "stock" oil pan which I believe for a stock pan is probably hard to find, and it is being written off for the wrong reasons. The main criteria to improve pump output is mainly the increased diameter of the tube. I have never heard the screen to be a significant issue. I am sure there are differences, but never heard that it matters.
 
There's not a SOUL on here arguing that has any empirical or scientific data, yall are just guessing and throwing out bad information. Nobody here has done any testing on what oil pickup works best with what pump or how much this pickup flows compared to that one. If so, post up some numbers of what a standard pickup can flow VS a high volume one and shut up the bench racin.
 
Three more post needed to get to 100 on New Year Eve....going...going

actually 2 now...lol
 
RustyRatRod said:
There's not a SOUL on here arguing that has any empirical or scientific data, yall are just guessing and throwing out bad information. Nobody here has done any testing on what oil pickup works best with what pump or how much this pickup flows compared to that one. If so, post up some numbers of what a standard pickup can flow VS a high volume one and shut up the bench racin.
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I have a Chrysler small block performance book written by Larry Atherton way back in the day, a Chrysler engine book from back in the day, and a current stroker small block book by Jim szilagy.
All 3 books claim that the number one improvement to improve pump output is to increase the diameter of the pickup tube.
Two of those book are written by Chrysler performance engineers.
None of those books claim any problems with the screen on the pick up. That's the best I can do as I was never that good at math lol.
 
Duane said:
I have a Chrysler small block performance book written by Larry Atherton way back in the day, a Chrysler engine book from back in the day, and a current stroker small block book by Jim szilagy.
All 3 books claim that the number one improvement to improve pump output is to increase the diameter of the pickup tube.
Two of those book are written by Chrysler performance engineers.
None of those books claim any problems with the screen on the pick up. That's the best I can do as I was never that good at math lol.
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Yes, I have the MP book by Larry Shepard that says the same thing. But it also says to use an HV pump, as do all the books you reference, I bet.
 
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