Variable displacement oil pump
Thread Starter
Drifting
Joined: May 2005
Posts: 1,419
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From: "Cedar Valley" (Northeastern) Iowa
Variable displacement oil pump
I recall reading that the new engine uses a "Variable Displacement Oil Pump" but I don't recall anyone discussing it.
Do any of you KNOW (not think they might know) the details?
I have this picture but haven't seen an explanation on how is works to make it Variable Displacement.
Do any of you KNOW (not think they might know) the details?
I have this picture but haven't seen an explanation on how is works to make it Variable Displacement.
Moderator
Joined: Feb 2006
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From: DFW Area TX
This is what their "Gen 5 Small Block Lubrication System" press release had to say about it:
Variable displacement enables the Gen 5’s oil pump to efficiently deliver oil as demanded by the engine’s operating conditions. Its dual-pressure control enables operation at a very efficient oil pressure at lower rpm coordinated with the Active Fuel Management and operation at a higher pressure at higher engine speeds providing a more robust lube system with aggressive engine operation. As with Gen 3 and Gen 4 Small Block engines, the new vane-type oil pump is crankshaft-driven.
Variable displacement enables the Gen 5’s oil pump to efficiently deliver oil as demanded by the engine’s operating conditions. Its dual-pressure control enables operation at a very efficient oil pressure at lower rpm coordinated with the Active Fuel Management and operation at a higher pressure at higher engine speeds providing a more robust lube system with aggressive engine operation. As with Gen 3 and Gen 4 Small Block engines, the new vane-type oil pump is crankshaft-driven.
Le Mans Master
Joined: Dec 2006
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From: H-Town Texas
Thread Starter
Drifting
Joined: May 2005
Posts: 1,419
Likes: 2
From: "Cedar Valley" (Northeastern) Iowa
TTT
Anyone know anything about it...... if obvious it has a "vane element", vane "control" and conventional G-Rotor on a common crank drive ..... but what does what to make it variabe displacement?
Anyone know anything about it...... if obvious it has a "vane element", vane "control" and conventional G-Rotor on a common crank drive ..... but what does what to make it variabe displacement?
Le Mans Master
Joined: Sep 2007
Posts: 5,526
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From: Mechanicsburg Pennsylvania
"Variable-displacement oil pumps help to minimize energy losses. Their active control matches the oil flow and pressure the engine needs, eliminating excess oil flow, significantly reducing the parasitic load on the engine crankshaft, and ultimately saving fuel.
In variable displacement pumps, changing the displacement volume controls the flow rate. Vane-pump designs have hydraulic and electrical controls and actuators that move the pump housing and vary the eccentricity of the rotor. Electronic control signals and solenoid control valves vary the pressure set points as operating conditions dictate."
Le Mans Master
Joined: Mar 2002
Posts: 5,955
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From: PNW
It has this:In variable displacement pumps, changing the displacement volume controls the flow rate. Vane-pump designs have hydraulic and electrical controls and actuators that move the pump housing and vary the eccentricity of the rotor. Electronic control signals and solenoid control valves vary the pressure set points as operating conditions dictate."
IMO, I doubt this is really gaining much in the way of saving lost energy from the engine. Only time a pure mechanical positive displacement pump wastes energy is when it's in pressure relief ... and to get to that condition the engine needs to be near or at redline anyway.
Racer
Joined: Dec 2004
Posts: 308
Likes: 14
There are two pumps in the photo, one is a vane style pump that is positioned on top of the gerotor style pump.
The vane pump housing has an inner and outer part:
the inner part is spring loaded to keep the vane pump at maximum displacement
when less displacement is needed the inner housing pivots around a fulcrum and presses against the spring in the photo. The small yellow seals visible in the photo create a chamber that is filled or emptied with oil, this is controlled by the black plastic valve in the bottom left of the photo.
The pump will default to maximum displacement if the control system goes out.
The vane pump is the pressure section of the assembly and the gerotor pump is the scavange portion of the assembly.
There are more photos of this on the LT1 press release page at GM/media.
Clever design!
Thanks for the link.
The vane pump housing has an inner and outer part:
the inner part is spring loaded to keep the vane pump at maximum displacement
when less displacement is needed the inner housing pivots around a fulcrum and presses against the spring in the photo. The small yellow seals visible in the photo create a chamber that is filled or emptied with oil, this is controlled by the black plastic valve in the bottom left of the photo.
The pump will default to maximum displacement if the control system goes out.
The vane pump is the pressure section of the assembly and the gerotor pump is the scavange portion of the assembly.
There are more photos of this on the LT1 press release page at GM/media.
Clever design!
Thanks for the link.
Last edited by k wright; Mar 3, 2013 at 06:05 AM.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,943
Likes: 12,359
From: NE South Carolina
I recall reading that the new engine uses a "Variable Displacement Oil Pump" but I don't recall anyone discussing it.
Do any of you KNOW (not think they might know) the details?
I have this picture but haven't seen an explanation on how is works to make it Variable Displacement.
Do any of you KNOW (not think they might know) the details?
I have this picture but haven't seen an explanation on how is works to make it Variable Displacement.
The C7 is the first Vette to use a "Variable Volume" oil pump. Other cars are doing the same versus just using a "pressure limit spring" which has been in oil pumps" forever!" That simple old system just bypasses the oil that is still being flowing through the pump and sends oil back to the pump inlet.
A variable volume pump truly has the pump pushing less oil so it consumes less power when higher pressure is not needed. A computer controls a solenoid that moves the pump outer case relative to the moving pump vanes so it's not working as hard to increase oil pressure when not needed. That is what you see low pressure at times and occasionally a stepped increase in pressure at relatively the same engine rpm!
Last edited by JerryU; May 25, 2019 at 05:19 PM.
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E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,943
Likes: 12,359
From: NE South Carolina
^^^
I didn't look at the date! How did this Thread pop in my email?? Perhaps someone responded today then deleted the post! That can't be it, I never had posted on that thread! In fact in Feb/March 2013 I had placed hold money on a C7 but had no idea it had a variable volume oil pump!
Have enough current posts to respond to, don't need more!
As you know I have lots of pics I made in my Vette pic files that answer questions I ask myself!
I didn't look at the date! How did this Thread pop in my email?? Perhaps someone responded today then deleted the post! That can't be it, I never had posted on that thread! In fact in Feb/March 2013 I had placed hold money on a C7 but had no idea it had a variable volume oil pump!
Have enough current posts to respond to, don't need more!
As you know I have lots of pics I made in my Vette pic files that answer questions I ask myself!
Last edited by JerryU; May 25, 2019 at 08:39 PM.
Moderator
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From: DFW Area TX
Are you sure it popped in your email? Could you have possibly scrolled down in a thread and hit the "Related Threads"? That's how most of these long dead threads get resurrected. You can turn off "Related Threads" in your User Control Panel (User CP > Edit Options > Disable Related Threads (in the Thread Display Options section)).
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,943
Likes: 12,359
From: NE South Carolina
^^^^
That must have been what happened, Thanks!
As some of my posts, I was on my large iPad that sits on the book shelf on my Treadmill while walking at a quick pace on an incline! Do that every day! (Makes the time go by quickly!)
Then if I see something where I have a pic, email a link to that page so I can open on my computer when I finish and post a pic!
That must have been what happened, Thanks!
As some of my posts, I was on my large iPad that sits on the book shelf on my Treadmill while walking at a quick pace on an incline! Do that every day! (Makes the time go by quickly!)
Then if I see something where I have a pic, email a link to that page so I can open on my computer when I finish and post a pic!
Last edited by JerryU; May 26, 2019 at 05:11 AM.