Does a high volume and/or high pressure oil pump actually move more oil through?
08-11-2012, 12:07 AM
#21
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Crate motor LS1. Car is built around a 8.7:1 lb/hp class and it'll weigh about 2500lbs after the LS1 swap so it can't make much more than 320 rwhp. 2700 (with driver)/320 = 8.4. If we run 275 tires we get a 0.4 break on the power weight so we can actually be 8.3:1. Thus a bone stock LS1 is perfect for the intended use.
Then why do I see 70-80 on track when the car isn't up to temp? The later LS4 pump I have has a 42psi relief spring. My understanding from a post earlier in this thread is that the bypass can't shunt all of the oil when it's viscosity is high (thicker). This is why you see elevated pressure numbers until the oil is hot. No?
Also, the LS4 pump at 42psi relief is higher than the standard LS6 pump which is 32 I think. So in my case comparing LS4 to LS6 pumps the LS4 is higher volume and higher pressure, thus it pushes more oil right? Add to that the fact that Kurt says the high volume pumps don't have corresponding changes in bypass orifice size so the spring actually acts as a higher pressure relief with the higher volume pump.
Can you elaborate? To be honest I don't hear any clattering or issues. I run a stock cam with the '02-'04 springs and I have to run stock mufflers per my class so my car doesn't have a noisy valvetrain or loud exhaust.
I thought my pressures were in line with what the one gentleman described above. I.e. at colder temps the oil is thick an the bypass circuit can't shut all of the excess flow. Then when the oil gets 250+ and thins out the pressure comes back down to the point the bypass can control pressure and keep it in the mid 40s-50.
How does any of this indicate air/oil? I'm not trying to debate, just trying to get a full understanding of this stuff. I mean if I was aerating the oil I don't see how my 123k engine would have stood up to 2 seasons of abuse and still make 365 rwhp on 93 octane with a conservative tune.
Excellent analogy... I get it now. So the volume does increase with rpm until it levels off, but the rate of increase falls off to the point it plateaus and eventually declines.
Does this recommendation apply even with the use of a large oil cooler and a 3-quart Accusump? Any need to look into the windage tray and crank scraper from I-J Racing or is this overkill?
Are there any LSX applications where a high volume pump is an asset? Other than the DOD motors that they're actually designed for. Does this only apply to loose race motors?
What about situations with sudden loading of the motor. I read something that mentioned the benefit of a high volume pump maintaining pressure and building it faster when the oil was hot/thin in a racecar. Hot/thin oil flows out of bearings more easily reducing pressure. I.e I'm toward the end of a race, oil is pushing 270 (Raced with NARRA at VIR a few weeks back and it was 108 ambient!) and I'm get held up by a slower driver in a bad spot... rpms fall I can't make a downshift and I have to get my foot back in it. Does anything like that make a difference?
Anyone know which pressure differential the OEM filter bypass opens? Would running a high volume pump create a scenario where the filter would be in bypass more often?
Also, the LS4 pump at 42psi relief is higher than the standard LS6 pump which is 32 I think. So in my case comparing LS4 to LS6 pumps the LS4 is higher volume and higher pressure, thus it pushes more oil right? Add to that the fact that Kurt says the high volume pumps don't have corresponding changes in bypass orifice size so the spring actually acts as a higher pressure relief with the higher volume pump.
The pressure you describe in your car is classic air/oil mix, you will sometimes hear slightly louder clattering of the valve gear when you come off track that quiets back down after running a few minutes. I had some that would run as low as 30 psi in the early years of Motorola cup.
I thought my pressures were in line with what the one gentleman described above. I.e. at colder temps the oil is thick an the bypass circuit can't shut all of the excess flow. Then when the oil gets 250+ and thins out the pressure comes back down to the point the bypass can control pressure and keep it in the mid 40s-50.
How does any of this indicate air/oil? I'm not trying to debate, just trying to get a full understanding of this stuff. I mean if I was aerating the oil I don't see how my 123k engine would have stood up to 2 seasons of abuse and still make 365 rwhp on 93 octane with a conservative tune.
The LS pump runs faster than it can properly fill at higher rpm, so when you see a flow graph the gallons per minute is like a hill, it climbs smoothly,levels, then starts dropping off. If you can imagine a turnstile type door leading into a building that had a power drive you could speed up. Run the turnstile slow with a group of people out side telling two to get in each section. They can fit and you just keep loading two at a time. If you keep speeding up the turnstile the time the people can get in gets to short and suddenly only one can get in as the opening goes by, this is volume decreasing with speed.
Originally Posted by 427
The engine is pretty constant in its needs, at 250F it will consume about 4.5-5 gallons per minute. As the pump runs faster it will not be able to keep up with this demand and flow/pressure drops. The standard volume pump can keep up with your needs at 6500 and that pan looks much better than the batwing (the batwing is not great),it reminds me of the road race Moroso. I would shim the pump for your dads car and limit the pushrods with the standard volume pump, that is something that should be much better than your car with the batwing pan combo.
Kurt
Kurt
Are there any LSX applications where a high volume pump is an asset? Other than the DOD motors that they're actually designed for. Does this only apply to loose race motors?
What about situations with sudden loading of the motor. I read something that mentioned the benefit of a high volume pump maintaining pressure and building it faster when the oil was hot/thin in a racecar. Hot/thin oil flows out of bearings more easily reducing pressure. I.e I'm toward the end of a race, oil is pushing 270 (Raced with NARRA at VIR a few weeks back and it was 108 ambient!) and I'm get held up by a slower driver in a bad spot... rpms fall I can't make a downshift and I have to get my foot back in it. Does anything like that make a difference?
Anyone know which pressure differential the OEM filter bypass opens? Would running a high volume pump create a scenario where the filter would be in bypass more often?
Last edited by Cobra4B; 08-11-2012 at 12:26 AM.
08-11-2012, 06:26 AM
#22
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Is that the class Danny Popp runs his corvette in? He runs a near stock engine in his.
High pressure is partially from the by-pass flow. Your engine consumes less oil when the temperature is lower as the internal leakage is reduced. Clearance increases with temperature, the lifters have the most leakage from memory.
If you don't hear the clattering your application is ok I believe. The clattering happens when the lifters get the air oil mix, it is reduced when they get clean pure oil after idling for a short time. The restricted pushrods can help with oil being consumed in the system.
If you are not getting air in the oil, adding a simple shim or using the high volume/pressure pump spring will raise the pressure with a stock pump.
Oil coolers and accusumps do not increase volume as they do not consume oil from the system although they can add drag. You can counteract this by shimming the pump.
I use the high volume pump on some engines with piston oilers if they operate at low rpm high power/load, like turbocharged trucks pulling trailers. My truck will hit 9 psi boost at 26-2800 rpm with the converter locked going up a mountain and maintain that load for two minutes. The low speed and high consumption call for the added volume. The LS9 engine also uses a high volume pump for piston oilers.
If your pan design allows the full length windage tray, that help speed oil return. That is always a good thing but hard to test. I have never been able to verify a crank scraper helping/hurting, so I do not use them.
The fast loading does not really change oil needs and will not hurt the engine.
The factory oil filter by-pass opens around 10-12psi. On road race engines I would gut them and weld the passage shut.
The high volume pump in your application can only cause cavitation and additional heat, it has no positive attributes that can help you.
Sounds like you are having a blast! I was at VIR last summer and it looks incredible. I did a little autocross stuff on the skid pad but never went out on the big track.
Kurt
High pressure is partially from the by-pass flow. Your engine consumes less oil when the temperature is lower as the internal leakage is reduced. Clearance increases with temperature, the lifters have the most leakage from memory.
If you don't hear the clattering your application is ok I believe. The clattering happens when the lifters get the air oil mix, it is reduced when they get clean pure oil after idling for a short time. The restricted pushrods can help with oil being consumed in the system.
If you are not getting air in the oil, adding a simple shim or using the high volume/pressure pump spring will raise the pressure with a stock pump.
Oil coolers and accusumps do not increase volume as they do not consume oil from the system although they can add drag. You can counteract this by shimming the pump.
I use the high volume pump on some engines with piston oilers if they operate at low rpm high power/load, like turbocharged trucks pulling trailers. My truck will hit 9 psi boost at 26-2800 rpm with the converter locked going up a mountain and maintain that load for two minutes. The low speed and high consumption call for the added volume. The LS9 engine also uses a high volume pump for piston oilers.
If your pan design allows the full length windage tray, that help speed oil return. That is always a good thing but hard to test. I have never been able to verify a crank scraper helping/hurting, so I do not use them.
The fast loading does not really change oil needs and will not hurt the engine.
The factory oil filter by-pass opens around 10-12psi. On road race engines I would gut them and weld the passage shut.
The high volume pump in your application can only cause cavitation and additional heat, it has no positive attributes that can help you.
Sounds like you are having a blast! I was at VIR last summer and it looks incredible. I did a little autocross stuff on the skid pad but never went out on the big track.
Kurt
Crate motor LS1. Car is built around a 8.7:1 lb/hp class and it'll weigh about 2500lbs after the LS1 swap so it can't make much more than 320 rwhp. 2700 (with driver)/320 = 8.4. If we run 275 tires we get a 0.4 break on the power weight so we can actually be 8.3:1. Thus a bone stock LS1 is perfect for the intended use.
Then why do I see 70-80 on track when the car isn't up to temp? The later LS4 pump I have has a 42psi relief spring. My understanding from a post earlier in this thread is that the bypass can't shunt all of the oil when it's viscosity is high (thicker). This is why you see elevated pressure numbers until the oil is hot. No?
Also, the LS4 pump at 42psi relief is higher than the standard LS6 pump which is 32 I think. So in my case comparing LS4 to LS6 pumps the LS4 is higher volume and higher pressure, thus it pushes more oil right? Add to that the fact that Kurt says the high volume pumps don't have corresponding changes in bypass orifice size so the spring actually acts as a higher pressure relief with the higher volume pump.
Can you elaborate? To be honest I don't hear any clattering or issues. I run a stock cam with the '02-'04 springs and I have to run stock mufflers per my class so my car doesn't have a noisy valvetrain or loud exhaust.
I thought my pressures were in line with what the one gentleman described above. I.e. at colder temps the oil is thick an the bypass circuit can't shut all of the excess flow. Then when the oil gets 250+ and thins out the pressure comes back down to the point the bypass can control pressure and keep it in the mid 40s-50.
How does any of this indicate air/oil? I'm not trying to debate, just trying to get a full understanding of this stuff. I mean if I was aerating the oil I don't see how my 123k engine would have stood up to 2 seasons of abuse and still make 365 rwhp on 93 octane with a conservative tune.
Excellent analogy... I get it now. So the volume does increase with rpm until it levels off, but the rate of increase falls off to the point it plateaus and eventually declines.
Does this recommendation apply even with the use of a large oil cooler and a 3-quart Accusump? Any need to look into the windage tray and crank scraper from I-J Racing or is this overkill?
Are there any LSX applications where a high volume pump is an asset? Other than the DOD motors that they're actually designed for. Does this only apply to loose race motors?
What about situations with sudden loading of the motor. I read something that mentioned the benefit of a high volume pump maintaining pressure and building it faster when the oil was hot/thin in a racecar. Hot/thin oil flows out of bearings more easily reducing pressure. I.e I'm toward the end of a race, oil is pushing 270 (Raced with NARRA at VIR a few weeks back and it was 108 ambient!) and I'm get held up by a slower driver in a bad spot... rpms fall I can't make a downshift and I have to get my foot back in it. Does anything like that make a difference?
Anyone know which pressure differential the OEM filter bypass opens? Would running a high volume pump create a scenario where the filter would be in bypass more often?
Then why do I see 70-80 on track when the car isn't up to temp? The later LS4 pump I have has a 42psi relief spring. My understanding from a post earlier in this thread is that the bypass can't shunt all of the oil when it's viscosity is high (thicker). This is why you see elevated pressure numbers until the oil is hot. No?
Also, the LS4 pump at 42psi relief is higher than the standard LS6 pump which is 32 I think. So in my case comparing LS4 to LS6 pumps the LS4 is higher volume and higher pressure, thus it pushes more oil right? Add to that the fact that Kurt says the high volume pumps don't have corresponding changes in bypass orifice size so the spring actually acts as a higher pressure relief with the higher volume pump.
Can you elaborate? To be honest I don't hear any clattering or issues. I run a stock cam with the '02-'04 springs and I have to run stock mufflers per my class so my car doesn't have a noisy valvetrain or loud exhaust.
I thought my pressures were in line with what the one gentleman described above. I.e. at colder temps the oil is thick an the bypass circuit can't shut all of the excess flow. Then when the oil gets 250+ and thins out the pressure comes back down to the point the bypass can control pressure and keep it in the mid 40s-50.
How does any of this indicate air/oil? I'm not trying to debate, just trying to get a full understanding of this stuff. I mean if I was aerating the oil I don't see how my 123k engine would have stood up to 2 seasons of abuse and still make 365 rwhp on 93 octane with a conservative tune.
Excellent analogy... I get it now. So the volume does increase with rpm until it levels off, but the rate of increase falls off to the point it plateaus and eventually declines.
Does this recommendation apply even with the use of a large oil cooler and a 3-quart Accusump? Any need to look into the windage tray and crank scraper from I-J Racing or is this overkill?
Are there any LSX applications where a high volume pump is an asset? Other than the DOD motors that they're actually designed for. Does this only apply to loose race motors?
What about situations with sudden loading of the motor. I read something that mentioned the benefit of a high volume pump maintaining pressure and building it faster when the oil was hot/thin in a racecar. Hot/thin oil flows out of bearings more easily reducing pressure. I.e I'm toward the end of a race, oil is pushing 270 (Raced with NARRA at VIR a few weeks back and it was 108 ambient!) and I'm get held up by a slower driver in a bad spot... rpms fall I can't make a downshift and I have to get my foot back in it. Does anything like that make a difference?
Anyone know which pressure differential the OEM filter bypass opens? Would running a high volume pump create a scenario where the filter would be in bypass more often?
08-11-2012, 09:04 AM
#23
Then why do I see 70-80 on track when the car isn't up to temp? The later LS4 pump I have has a 42psi relief spring. My understanding from a post earlier in this thread is that the bypass can't shunt all of the oil when it's viscosity is high (thicker). This is why you see elevated pressure numbers until the oil is hot. No?
Also, the LS4 pump at 42psi relief is higher than the standard LS6 pump which is 32 I think. So in my case comparing LS4 to LS6 pumps the LS4 is higher volume and higher pressure, thus it pushes more oil right? Add to that the fact that Kurt says the high volume pumps don't have corresponding changes in bypass orifice size so the spring actually acts as a higher pressure relief with the higher volume pump.
Also, the LS4 pump at 42psi relief is higher than the standard LS6 pump which is 32 I think. So in my case comparing LS4 to LS6 pumps the LS4 is higher volume and higher pressure, thus it pushes more oil right? Add to that the fact that Kurt says the high volume pumps don't have corresponding changes in bypass orifice size so the spring actually acts as a higher pressure relief with the higher volume pump.
For example, my stock LS6 had 70psi of oil pressure at redline when at normal operating temperature with the stock oil pump. With a Melling 10296 installed, it still has 70psi of oil pressure at redline when at normal operating temperature.
You see higher pressure at cold temperatures because the relief capacity of the pump is designed for normal operating temperature and cannot handle the volume of cold oil. This design parameter (limitation) is of no concern at normal operating temperatures with normal oil viscosity. (Theoretically, you could run a high enough oil viscosity such that the pump's relief capacity would be exceeded even at normal operating temperatures.)
08-11-2012, 10:33 AM
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Is that the class Danny Popp runs his corvette in? He runs a near stock engine in his.
The factory oil filter by-pass opens around 10-12psi. On road race engines I would gut them and weld the passage shut.
Sounds like you are having a blast! I was at VIR last summer and it looks incredible. I did a little autocross stuff on the skid pad but never went out on the big track.
Kurt
The factory oil filter by-pass opens around 10-12psi. On road race engines I would gut them and weld the passage shut.
Sounds like you are having a blast! I was at VIR last summer and it looks incredible. I did a little autocross stuff on the skid pad but never went out on the big track.
Kurt
On a 2001 LS6 in my car or the 2004 LS1 GTO motor I'm prepping is the filter bypass part of the filter mount? I read in later engines they removed it and relied on a filter with a bypass. When you say you gut them and weld shut I assume you mean the pan? Who makes a good filter w/o an internal bypass? I've always run the K&N racing oil filters w/o issue. But as I've learned more I'm curious how often that circuit is in bypass and not filtering the oil. The filter doesn't go into bypass based on engine pressure correct? It's based on pressure differential i.e. the pressure drop created by the oil going through it right? So then wouldn't the only time this was in issue would be before the oil is fully up to temp and the pump is making 70-80 psi of pressure? Or, can the filter or filter bypass in the pan handle that w/o engaging?
VIR is a blast... if you ever get to drive a car out there you should. Completely addicting hobby.
The 32psi figure for an LS6 oil pump, and presumably the 42psi figure for an LS4 oil pump, do not represent the maximum oil pressure to which the pump is limited. Those figures (the 32 and the 42) represent the pressure at which bleed off begins to occur. For each pump, there is a maximum oil pressure which will not be exceeded in normal operation.
For example, my stock LS6 had 70psi of oil pressure at redline when at normal operating temperature with the stock oil pump. With a Melling 10296 installed, it still has 70psi of oil pressure at redline when at normal operating temperature.
You see higher pressure at cold temperatures because the relief capacity of the pump is designed for normal operating temperature and cannot handle the volume of cold oil. This design parameter (limitation) is of no concern at normal operating temperatures with normal oil viscosity. (Theoretically, you could run a high enough oil viscosity such that the pump's relief capacity would be exceeded even at normal operating temperatures.)
For example, my stock LS6 had 70psi of oil pressure at redline when at normal operating temperature with the stock oil pump. With a Melling 10296 installed, it still has 70psi of oil pressure at redline when at normal operating temperature.
You see higher pressure at cold temperatures because the relief capacity of the pump is designed for normal operating temperature and cannot handle the volume of cold oil. This design parameter (limitation) is of no concern at normal operating temperatures with normal oil viscosity. (Theoretically, you could run a high enough oil viscosity such that the pump's relief capacity would be exceeded even at normal operating temperatures.)
08-11-2012, 12:52 PM
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The road race engines I built that were wet sump was in the Corvette with the LS1-LS6 engine. I took out the pieces in the filter mount that was part of the pan and had a fabricator weld it shut. It is supposed to open only when the pressure drop is above the 10 psi, but I don't trust them. We used Wix or GM filters and the cars never left the paddock until oil temp was 180F so the oil filter by-pass was not required. The oil temp was never below 230 racing and exceeded 300 on a few tracks, but mostly 250-270 was common.
Danny was an instructor at the autocross deal at VIR, it was fun but not addicting. The road course stuff looks like more fun and I did take a ride at Kershaw in the second gen Camaro that Kyle at Detroit Speed drives, it was very cool!
Brian Finch runs one of my 427ci engines in his second gen Camaro, so I am hoping for another ride when I meet him!
Kurt
Danny was an instructor at the autocross deal at VIR, it was fun but not addicting. The road course stuff looks like more fun and I did take a ride at Kershaw in the second gen Camaro that Kyle at Detroit Speed drives, it was very cool!
Brian Finch runs one of my 427ci engines in his second gen Camaro, so I am hoping for another ride when I meet him!
Kurt
