|
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:
|
Quote:
|
Go back to school maxx
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???:confused: 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.:eek:**):JEKYLHYDE%/:o Barry is right about getting on a nerve with theories. Rick L.
|
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. |
Quote:
|
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:
|
Thanks Rick i do not like to argue over this stuff. :D
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. |
Quote:
|
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.
|
I give up**)
|
sounds like a win win!!
:LOL: Quote:
|
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. |
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 |
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.
|
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? |
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. |
oh i forgot to tell everyone, buy gld today!!!!
|
Quote:
|
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. |
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. |
| All times are GMT -7. The time now is 09:36 AM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: