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  #81 (permalink)  
Old 08-11-2010, 07:12 AM
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Your oil pressure connection is tied into the main oil galley. It does not matter if you are running 10wt at 3 psig or 80 wt at 50 psig, the flow rate will be identicle on a positive displacemetnt gear driven pump at a give rpm. Difference between standard volume 3 gpm and high volume is 3.25 gpm. so high volume is 10% more. The gauge tap is before the oil cooler, filter, lines not after. All factory set oil pump rv are set to releive at 60 psig, if you are below 60 psig your flow is identicle regardless of pressure. By the way your oil filter has a internal bypass set at 10-12 psig differential unless you have a high performance FL-1HP and then it is set 18-20 psig differential. If you have 90 psig you internal bypass is opening on your filter and you are bypassing you oil filter.




Quote:
Originally Posted by PLDRIVE View Post
Madmaxx i did not say anything about a standard pressure pump. You need to read again before u respond Also



Flow rate ( I am only concerned about solid roller engine in this example)
Engine 1
Lets say u have a standard volume standard pressure pump and you have not adjusted the relief pressure and you also have an oil cooler with 5 feet of hose. The engine idles at 10psi with 20w50 oil in it. How much oil do u think you will get to the valve train at idle Your relief valve is dumping the oil back in the pan due to resistance in the system, and the pump my not provide enough volume when the oil is hot.

Flow Rate
Engine 2
Engine 2 is exactly the same except it has a HPHV pump and 10w30 oil.
The oil pump and has been adjusted (Relief is set at 95psi cold oil). At operating temp the engines idles at 35psi. Which one has the higher flow rate.
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Old 08-11-2010, 09:34 AM
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Quote:
Originally Posted by madmaxx View Post
Your oil pressure connection is tied into the main oil galley. It does not matter if you are running 10wt at 3 psig or 80 wt at 50 psig, the flow rate will be identicle on a positive displacemetnt gear driven pump at a give rpm. Difference between standard volume 3 gpm and high volume is 3.25 gpm. so high volume is 10% more. The gauge tap is before the oil cooler, filter, lines not after. All factory set oil pump rv are set to releive at 60 psig, if you are below 60 psig your flow is identicle regardless of pressure. By the way your oil filter has a internal bypass set at 10-12 psig differential unless you have a high performance FL-1HP and then it is set 18-20 psig differential. If you have 90 psig you internal bypass is opening on your filter and you are bypassing you oil filter.
Will you please stop spouting facts based on physics. You're gonna get some guys upset. Everybody KNOWS you need 8 million pounds of oil pressure or your car will spontaniously combust..
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  #83 (permalink)  
Old 08-11-2010, 10:30 AM
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madmaxx Max you need to start getting better info than you are coming out with. M-57HV pump has a 25% LARGER GEAR AND VOLUME over the M-57HP. The spring inside the pump is what gives you the high pressure. Do you think that the oil pressure you read on your oil pressure gauge is the same at the oil filter housing as it is on the rocker arm shafts??? Not even close. Depending on motor and oil modifications about 15-30 psi differents. This is for side oils and Cammer motors. I little less for center oiler motors. This also means you are not, NOT getting the same oil pressure to rods #4, #8 on an FE motor you are getting to #1 & #5. As far as a bypass valve in oil filter, some do MOST DON'T. I run 135-138 psi warning up my motor at 1,200 rpms, when the motor is hot in the 180f coolant temp and oil temp is about 190f I idle at 35-40 psi and run 70-80 psi on the track. As far as filters it depends on the paper and how large the microns are in the paper, some are 5, others are 30 and up. Some filters are single stage others are dual stage. Dual stage are not the best IMO for any kind of motor. As far as Royal Purple, you keep drinking it. Barry is right about getting on a nerve with theories. Rick L.
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Old 08-11-2010, 11:57 AM
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Someone want to explain how you can have two different pressures, in a hydrualic system, fed by the same line? I think that is what you said Rick.

I understand how a volume difference can be achieved, but I cannot figure out you can have different pressure readings from any line that is tapped off another one, unless there is some type of pressure regulator installed.
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Old 08-11-2010, 01:27 PM
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Quote:
Originally Posted by vector1 View Post
pldrive

regarding flow rate, i have a crate engine 351/385 in one of the cars, and it uses -8 oil line, the pressure is read at the input on the front left side, it probably reads steady 40 lbs, less when hot. the oil is ran through the -8 lines, through an oil filter, through the oil cooler, and numerous 90 deg. bends. i don't know how this engine has survived, even hyd rollers, but it still runs fine. it is chipped to run to 6000rpm, and i haven't changed it for fear of tearing something up .
i guess i should have added, it could possibly take a lot less pressure to make an engine survive then believed. i could give a rats ass about the 90 deg bends or the filter restriciton, that was not the point, just part of the equation.
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Old 08-11-2010, 02:44 PM
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I give up, the oil pressure at your rocker arms is 0psig, dumb dumb. Oil is not compressible. Positive displacement pumps only generates the pressure required to deliver the flowrate. The oil pump spring does not make more pressure, it prevents the rv from relieving.

I have never read or seen anyone run oil pressures as high as you are using. I am surprised you are not experiencing bearing errosion.

As far as you main bearing the oil pressure is the same to all unless they are in series, but in reality the passages are all in parallel.

Good luck, you need it



Quote:
Originally Posted by RICK LAKE View Post
madmaxx Max you need to start getting better info than you are coming out with. M-57HV pump has a 25% LARGER GEAR AND VOLUME over the M-57HP. The spring inside the pump is what gives you the high pressure. Do you think that the oil pressure you read on your oil pressure gauge is the same at the oil filter housing as it is on the rocker arm shafts??? Not even close. Depending on motor and oil modifications about 15-30 psi differents. This is for side oils and Cammer motors. I little less for center oiler motors. This also means you are not, NOT getting the same oil pressure to rods #4, #8 on an FE motor you are getting to #1 & #5. As far as a bypass valve in oil filter, some do MOST DON'T. I run 135-138 psi warning up my motor at 1,200 rpms, when the motor is hot in the 180f coolant temp and oil temp is about 190f I idle at 35-40 psi and run 70-80 psi on the track. As far as filters it depends on the paper and how large the microns are in the paper, some are 5, others are 30 and up. Some filters are single stage others are dual stage. Dual stage are not the best IMO for any kind of motor. As far as Royal Purple, you keep drinking it. Barry is right about getting on a nerve with theories. Rick L.
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Old 08-11-2010, 02:47 PM
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Thanks Rick i do not like to argue over this stuff.

MadMaxx the info i provided did not come out of thin air. :You need to research before you answer.

Skuzzy this is simple example of what we are talking about (not to dumb it down to much).

a water hose exists a house at 5 psi (pessure regulator is on the spicket) makes a turn and goes vertical 10 feet. What do you think the pressure will be at the top of the hose, and what will the flow be??? 0 on both gravity is the resistant in this example.

If you have an engine with an oil cooler and several feet of hose and could take oil pressure readings from oil exiting the block , through the cooler, through the filter, back into the engine, up to the valve train, you will find that the pressure will continue to drop. FLOW RATE is affected. The oil pump has to push all that oil through the system which has RESISTANCE. To take it a step further heavy cold oil will have less flow and a greater pressure drop through the system at a SET pressure. What you have to remember is the pump has the relief valve on it (that is your pressure regulator). It pushes oil so when it hits a preset pressure it will not go any higher and will not overcome the resistance. Pressure is highest at the pump.
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Old 08-11-2010, 02:56 PM
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Quote:
Originally Posted by madmaxx View Post
I am surprised you are not experiencing bearing errosion.
All our "bearings" erode everyday.
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Old 08-11-2010, 03:07 PM
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Positive displacement pump = flowrate the same regardless of pressure. Centrifugal pump, like the water supply to your house, pressure stays the same but flowrate varies.
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Old 08-11-2010, 03:13 PM
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I give up
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Old 08-11-2010, 05:11 PM
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sounds like a win win!!




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Originally Posted by PLDRIVE View Post
I give up
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Old 08-11-2010, 05:19 PM
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If you have an engine with an oil cooler and several feet of hose and could take oil pressure readings from oil exiting the block , through the cooler, through the filter, back into the engine, up to the valve train, you will find that the pressure will continue to drop. FLOW RATE is affected.

Correct pressure will drop as you move down the circuit because the resistance in the system is dropping. Total flowrate from the oil pump will stay the same.





The oil pump has to push all that oil through the system which has RESISTANCE. To take it a step further heavy cold oil will have less flow and a greater pressure drop through the system at a SET pressure.

Cold oil will not flow any less than warm oil assuming your oil pump relief valve does not lift, you will have more oil pressure not more flowrate. There is less than 1% slippage in most positive displacment pumps.

What you have to remember is the pump has the relief valve on it (that is your pressure regulator). It pushes oil so when it hits a preset pressure it will not go any higher and will not overcome the resistance. Pressure is highest at the pump.

I agree, the relief valve lifts and recirculates to pump suction.
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Old 08-11-2010, 05:23 PM
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The lifter bouncing because of too much clearance is probably a good culprit.
I run a "rev Kit" which is some very light springs under the head.. between the head and the lifters, which keep the lifter in constant contact with cam...no bouncy bouncy!! This kit allows the use of very low valve spring pressures because the valve spring has only the valve to control. Imake sure that I blip the throttle constantly at idle to make sure the oil is getting to the lifter wheels...I idle at 600 rpm and redline at 8000rpm...
John
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Old 08-11-2010, 06:34 PM
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Make no doubt hydraulic lifters can bounce on the backside also with an agressive cam profile. Anything above 5.5K rpm you are risk. It is usually seen as valve float but if the hydraulic lifter is set near zero lash then you may not experience valve float. Some like Keith Craft make high rev lifters which add about 500 rpm over traditional hydraulic lifters.
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Old 08-12-2010, 06:13 AM
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Ok, hydraulics are not my comfort zone, electrical engineering is, but I can be taught.

I wish I could stick a picture in here. Take a pump feeding a one inch diameter line and off that line is four quarter inch diameter lines, spaced two inches apart.

At the end of each of the four quarter inch lines is a cover which does not allow the total volume of oil to pass, which the pump is capable of moving.

Now, in my pea brain, if I take a measurement of pressure at any point in that circuit, the pressure would be the same. Only the volume would differ.

I do understand if the pump is having to pump the liquid uphill, the pressure at the source, would be higher due to gravity and would taper off as you approached the high spot in the circuit. What happens if the lines are parallel to the ground, or run downhill, and gravity becomes moot or its effects are negated?
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Last edited by Skuzzy; 08-12-2010 at 06:15 AM..
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Old 08-12-2010, 07:37 AM
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I wish I could stick a picture in here. Take a pump feeding a one inch diameter line and off that line is four quarter inch diameter lines, spaced two inches apart.

At the end of each of the four quarter inch lines is a cover which does not allow the total volume of oil to pass, which the pump is capable of moving.

With a positive displacement pump the pump moves its entire capacity (volume) with every rotation, it does not have the ability to slip (cavitation) like a centrifugal pump. The clearances in a PDP are exponentially tighter than a centrifulgal. So if you block to much flow either your pump relief pops, your oil pump body cracks, or you dont have enough power to turn the pump.

Look at a garden hose dumping into a bucket driven by a centrifugal pump. You open the nozzle flow increases because you are reducing resistance in the circuit and the pump impeller does not recirculating as much since you get to it highest efficiency point.

You now use a positive displacement pump on your garden hose with the hose in a bucket, you open your nozzle and flowrate does not increase, you reduced pressure in the system but your flowrate stayed the same because the gears in the gear pump cannot pump anymore.
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Old 08-12-2010, 07:41 AM
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oh i forgot to tell everyone, buy gld today!!!!
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Old 08-12-2010, 08:19 AM
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Quote:
Originally Posted by madmaxx View Post
The oil pump has to push all that oil through the system which has RESISTANCE. To take it a step further heavy cold oil will have less flow and a greater pressure drop through the system at a SET pressure.

Cold oil will not flow any less than warm oil assuming your oil pump relief valve does not lift, you will have more oil pressure not more flowrate. There is less than 1% slippage in most positive displacment pumps.
is this a contradiction?
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Old 08-12-2010, 09:30 AM
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Assuming no PSV then flowrate will be the same cold, hot, low viscosity, high viscostiy. Pressure drop does not matter to a positive displacement pump until it reaches the material limits of what the pump is constructed from or driven by. I am not getting into volumetric vs mass flow and temperature correlations so all you fluid dynamic experts can go into the details.

I was quoting another post and the lower one was my reply. I suk at highlighting, I apologize for the confusion.
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Old 08-12-2010, 12:04 PM
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madmaxx, again, I wish I could drop a pic in here. Easier to visualize.

I was referencing a post that stated the pressures are not even between the mains. I still do not see how that is possible. I do not question the validity. I am just ignorant to how it can occur without some type of blockage in the oil feeds or some mains that are so open they all the volume of oil coming at them to bleed right on out without any back pressure at all.

I know I am not saying this well. A picture would be easier.
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