512Stroker
We are all here because we are not all there.
Boyz. Boyz ,Boys lets just say you are both right and put this to bed.
After all it is a Holiday
HV oil pump vs Stock oil pan
- Thread starter 512Stroker
- Start date
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After all it is a Holiday
512Stroker
We are all here because we are not all there.
Partner looks like you have quite the experience with the large displacement industrial power plants.
I also cut my teeth rebuilding DDA engines for Inland Diesel back in the earlier 80's even did a pair of sweet sixteens.
Did a hitch as a Service Engineer for Waukesha Engine wrenching on 12 & 16 cylinder engines up to 10,000 cid, worked in their Engineering Lab as a Dyno Tech for 5 years.
Retired from a little company called Cummins Engine Company.
Dale Davies
Well-Known Member
I would call a flow volume problem caused by tbe roller rockers needing more oil flow.
Engine master did a 440 mopar two or three weeks ago ....Tested 3 oil pumps ....Used taahe 440 since the pump is external......Used a stock Melling....High Pressure Melling and a HV Melling.....
The Dyno HP only varied about 1 HP between all 3 pumps.....oil pressure at idle was the big difference with the HV pump ......
And the Host who are Mopar guys all said they would run the HV pump on the street....
The Dyno HP only varied about 1 HP between all 3 pumps.....oil pressure at idle was the big difference with the HV pump ......
And the Host who are Mopar guys all said they would run the HV pump on the street....
From D. Vizards SBC book:
Oil pumps must be sized to satisfy low, not high, RPM requirements. A misconception is that the engines need more oil as RPM increases [ the clearances do not change with rpm, my insert! ] ......Consequently all oil pumps have excess delivery at peak rpm. If bearing clearances are at the wide limit....., tightening up the pump clearances helps idle oil pressure to the tune of 2-3 psi. AT A 650 rpm IDLE, 10 PSI is FINE, BUT THE PRESSURE BETTER BE UP UP TO ABOUTY 35 PSI BY 1800 RPM [ OR SO ].
Oil pumps must be sized to satisfy low, not high, RPM requirements. A misconception is that the engines need more oil as RPM increases [ the clearances do not change with rpm, my insert! ] ......Consequently all oil pumps have excess delivery at peak rpm. If bearing clearances are at the wide limit....., tightening up the pump clearances helps idle oil pressure to the tune of 2-3 psi. AT A 650 rpm IDLE, 10 PSI is FINE, BUT THE PRESSURE BETTER BE UP UP TO ABOUTY 35 PSI BY 1800 RPM [ OR SO ].
as with any pump, volume increases with rpm.
The increase in pressure with a higher volume pump is because there is more oil entering the passage.
Oil mods should be done to take full advantage of a high volume pump
The increase in pressure with a higher volume pump is because there is more oil entering the passage.
Oil mods should be done to take full advantage of a high volume pump
higher volume through an unmodified orifice increases pressure not volume through the same size orifice.
spend a few bucks and watch the show....
the Host liked the higher oil pressure at idle....
Phreakish
Well-Known Member
Clearances don't, but the forces pulling on the oil within the rod journal will be far greater at RPM. The power needed to run any oil pump is negligible, so a HV oil pump just makes good sense. Unless one is tracking actual pressure at the point of interest (rod journal, cam bearing, rockers) then one must assume worst case and ensure the system has every chance for success.
Fishmen,
There is a limit to the amount of oil that can drawn through the pump up. When that limit is reached, it pulls air. Bearings do not like air...
Here is a quote from the old Mopar Perf book by Mopar man Larry Atherton on the s/b pump:
'Bob Tarozzi determined during his bench testing of various Chr oil pumps that the major restriction to their efficiency was the limited cross sectional area of the p/up tubes. Especially when the tall Hemi rotor has been installed, the pump is capable of pumping more oil than the p/up can draw out of the pan. Therefore, he recommends a larger diameter p/up tubes in all instances'. This is the SB pump.
BB pump:
'The B pump supplies more than twice the oil necessary for reliable engine operation.....Restrictions on the pressure side of the system will have minimal effect on engine reliability, however, any substantial restriction in the suction side can cause aeration & cavitation......This will spell sure disaster for a race engine at high rpm & can only be avoided by increasing oil delivery to the pump'. [ Italics in original.
There is a limit to the amount of oil that can drawn through the pump up. When that limit is reached, it pulls air. Bearings do not like air...
Here is a quote from the old Mopar Perf book by Mopar man Larry Atherton on the s/b pump:
'Bob Tarozzi determined during his bench testing of various Chr oil pumps that the major restriction to their efficiency was the limited cross sectional area of the p/up tubes. Especially when the tall Hemi rotor has been installed, the pump is capable of pumping more oil than the p/up can draw out of the pan. Therefore, he recommends a larger diameter p/up tubes in all instances'. This is the SB pump.
BB pump:
'The B pump supplies more than twice the oil necessary for reliable engine operation.....Restrictions on the pressure side of the system will have minimal effect on engine reliability, however, any substantial restriction in the suction side can cause aeration & cavitation......This will spell sure disaster for a race engine at high rpm & can only be avoided by increasing oil delivery to the pump'. [ Italics in original.
Rat Bastid
Dunamis Metron
It doesn’t matter what Vizard says. He is 99.9999999% chevy. And I can’t think of anything that should idle at 650 rpm. It’s hard on the lifters and cam.
Rat Bastid
Dunamis Metron
When was that book written? Oils today are nothing like they were then, plus most way back then we running a 20w50 or even a straight 50. Getting that glue like oil up the pickup tube was nearly impossible. I’m not saying don’t increase the pick up tube diameter, I’m saying it’s not as critical as it once was, and I’m saying that for 99.999% of the people building stuff on here it will never matter. As for misquoting you, that’s on you. Ever notice it’s you who says I misquote? You say crap and then get called on it.
Dale Davies
Well-Known Member
What was the standard volum
What was the standard volumn pump idle oil pressure? Also a factor is compression ratio. A high compression engine pushes down on the rod bearings a bit more than low compression, even at idle.
At idle the engine loads are low, so pressure is not a big issue on the crankshaft. Flow is required to provide an adequate oil film. The camshaft journal bearing load does not change appreciably between idle and red line. Now that said, to accelerate the valvetrain to open the valves puts some extra load on those bearings.
The Buick small V8 going back to the aluminium 215 and many ither engines oil the cam journals through the top of the bearing. This lets oil spill out the sides of the bearing without developing a good oil film. From the front of the engine, the oil hole in the cam bearing should be at about 4 o'clock. This gets the oil in between the bearing and cam journal while there is still clearance to spread out and develop a good film. This helps keep oil pressure up.
Rat, take note. This is important. With the oiling system properly set up, 10# oil pressure at idle is generally adequate. High compression should have a bit more. By 2000RPM you should have 35 to 40#. At 6500RPM 65 to 70 PSI.
Again I state that oil pressure is a balance between the pump output volumn at X RPM and "leaks" in the engine. These leaks are from bearing clearances, rod side clearance, cam bearing clearance, lifter bores, roller lifter bearings, rocker arm bearings. Rebuilt Ford FE engines can have low oil pressure if a galley plug is left out behind the distributor. This is installed behind the timing cover and through the the front of the block. This is an unwanted leak.
If an engine requires a HV oil pump or the owner thinks it will be a benefit, go for it. When you add components that require lubrication from the engine oil system, like maybe a blower or turbocharger, then a HV pump is required because another leak has been added.
Dale Davies
Well-Known Member
512Stroker, after all the yip yap and seeing what David Vizard has to say as posted by Bewy, run what you want for an oil pump. HV/HP might push oil up to the valve covers. A HV will build pressure quicker until the relief valve opens and dumps the excess into the pan.
For Rat, who will have an issue with David Vizard, he has built a huge number of engines over his years, covering numerous makes. The man has probably forgotten more than you have learned.
512, just enjoy your engine and the car. Happy Thanksgiving bud.
Dale Davies
Well-Known Member
Ford factory recommended idle for Flatties was 400RPM. You would not know they are running.
Phreakish
Well-Known Member
Higher volume through an orifice doesn't increase the volume through the orifice? Sounds like a contradiction. Higher volume through the same orifice causes a higher pressure as a result of passing more volume. There is indeed an increase in volume.
In an engine, the HV pump increases volume only prior to the bypass opening. Once the bypass opens, it's no different really. The pump is only moving more oil per rpm, not pushing it harder and will only increase volume of flow prior to the bypass opening.
But any engine that will see significant load between idle and when the bypass opens, like many hot street motors, would benefit from a HV pump. A standard pump may not hit relief pressure until 3k rpm, where the HV may do it as low as 1500.
Phreakish
Well-Known Member
Doesn't make sense - the oil will accelerate to satisfy the equilibrium conditions. Higher volume will mean the velocity of the oil in the pickup will increase. At the extreme, the concern would be that the drawing force of the pump would reduce pressure in the pickup until cavitation occurs. It would require the pulling pressure of the pump to exceed the vapor pressure of the base oil.
The math isn't hard to figure out. At 8gpm, or 1848 cubic inches per minute, and a 1/2" oil pickup diameter (~.2 sq inches), would create a flow velocity of 9240 in/m, or 770ft/m, or 12 ft/s (about 9mph). Hardly that fast. If a HV pump increases flow capacity by 25%, it's not going to suddenly strain an already unstrained system.
For reference, the pumps tested by engine masters on a 440 had a max volume flow rate (at max rpm) of 6gpm (4.9 for a stock pump). This would make velocities through the pickup about 9ft/s (7.3ft/s for stock). Notably, both the HV and the HP made the same max flow, and the same max pressure. Which means that both pumps had a 'high pressure' bypass spring, it's just that the HV model also has deeper rotors for reaching max pressure sooner - the HP and the STD idled at 32psi, while the HV idled at 49. Standard maxed out at 54psi, the HV and HP at 72-75. What was also notable, is that all pumps seemed to reach near their max pressure by 3k rpm (min rpm on their dyno). None of the power results suggested any measurable impact to HP. The total spread in measured HP was 5, with the HV making 1.1 hp more than stock and the HP making 3.1 more than stock. The Milodon super-high flow (6.6 gallons @ 80psi) made 538.1 hp - the only one to lose power vs stock.
As far as a pump 'emptying' a pan - at 6gpm, that's 24 quarts per minute, or 2.5 seconds per quart. How long does it take a quart to drain back to the pan? 2.5 seconds seems doable IMO, especially since the majority of oil flow is likely going through the crank and rod ends, and being flung right back into the sump area. With a nominal capacity of 5 quarts, having 1 quart return to the sump every 2.5 seconds seems fairly reasonable still.
Nothing in these numbers seems to make a HV pump a problem. None seem to indicate a stock pump is a good choice unless building a stock engine with stock expectations. A HP pump might work well with something that lives above 3k, but why give up the better idle/low-rev oil supply and faster pressure build-up at start-up?
Swinger 340
Well-Known Member
You all are giving me a headache with all your numbers on oil pressures, from a simple question of "can I use a H/V oil pump in a stock oil pan without problems". He seems to have a mostly stock motor and not a full blown one. In 87' I had built two 340's, also mostly stock (forged 30 over bores with DC cams, one auto and the other manual cams). Both had installed H/V oil pumps, one 5 Qt.(dart) and the other 6 Qt(van) pans. Still running them and never an issue with either one. I run both hard at times and never ran the pans dry as some believe will happen. I did a test demo at a car show years ago that called to drain the oil and water from a 225 six and see how long it would take to blow up. 40 min. at 2,000 rpm's the cam broke. My belief is if you hear a tick or knock, you have a mechanical issue that needs to be addressed. I have seen dirty heads that would not allow oil to return to the pan, but that is another thread.
It's physically impossible to flow more fluid through a sized orifice. the column of fluid is maintained by volume.
Dale Davies
Well-Known Member
An orfice will allow X volumn to pass at X pressure. If you change pressure to Y the flow will change some, but not substantially. And there is a point that increasing pressure more has no further affect on flow volumn.
Phreakish
Well-Known Member
Untrue. Mass flow rate is a function of cross section and velocity, velocity is the result of pressure differential.
The only point at which this changes is when the flow reaches Mach 1, at which point the flow is saturated.
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