oil pump mod idea to think about
11-22-2003, 09:59 PM
#1
oil pump mod idea to think about A guy asked a question about ported oil pumps and it got me to thinking…
I (and many others) have ported our own LS6 (01+) pumps and seen quite a bit of gain for ex:
Stock, I had 30psi at idle and 55psi at 4000RPM
Ported, I have 40psi at idle and 65psi at 3500RPM
So here is my question:
Looking at the pump (the cover plate off), there is a difference of 0.005" between the surface of the gears (gear is 0.422" thick) and the surface of housing (distance from cover surface to bearing surface for gear is 0.427").
With this in mind, what would happen if the difference were cut to say 0.003"? I would "think" the aluminum housing has a higher expansion rate than the steel gears and in that case, the distance might actually be growing to 0.007" or more when under operating conditions. It seems to me that if the tolerances could be taken up, you could gain that much more oil flow.
I (and many others) have ported our own LS6 (01+) pumps and seen quite a bit of gain for ex:
Stock, I had 30psi at idle and 55psi at 4000RPM
Ported, I have 40psi at idle and 65psi at 3500RPM
So here is my question:
Looking at the pump (the cover plate off), there is a difference of 0.005" between the surface of the gears (gear is 0.422" thick) and the surface of housing (distance from cover surface to bearing surface for gear is 0.427").
With this in mind, what would happen if the difference were cut to say 0.003"? I would "think" the aluminum housing has a higher expansion rate than the steel gears and in that case, the distance might actually be growing to 0.007" or more when under operating conditions. It seems to me that if the tolerances could be taken up, you could gain that much more oil flow.
11-22-2003, 11:34 PM
#2
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How would you do it, would you mill .002 off of the cover?
Maybe that gap is designed to compensate for expansion of the gear, or possibly it's used to keep too much heat from building up, or as some type of built in maximim pressure regulation.
If heat makes materials expand then it seems that the gap would get smaller as the pump gets hotter. I would think that the aluminum would expand more, but because the material get thicker when it get hotter then the gap might stay the same. Cover gets 2 mills thicker, but the area in contact with the pump does too and pushes the cover away an equal distance.
Maybe that gap is designed to compensate for expansion of the gear, or possibly it's used to keep too much heat from building up, or as some type of built in maximim pressure regulation.
If heat makes materials expand then it seems that the gap would get smaller as the pump gets hotter. I would think that the aluminum would expand more, but because the material get thicker when it get hotter then the gap might stay the same. Cover gets 2 mills thicker, but the area in contact with the pump does too and pushes the cover away an equal distance.
11-23-2003, 11:07 AM
#3
I figured it could be ground on a Blanchard grinder.
What I figured was as the aluminum housing grows its walls will get “taller” and thus push the cover plate out a few more thousandths. The gears should grow slightly but at even 300 degrees, steel is still very stable. If the housing grows and the gears don’t, then that should result in more pumping loss right?
I might be trying to reinvent the wheel here, but has anyone else thought of/tried this?
What I figured was as the aluminum housing grows its walls will get “taller” and thus push the cover plate out a few more thousandths. The gears should grow slightly but at even 300 degrees, steel is still very stable. If the housing grows and the gears don’t, then that should result in more pumping loss right?
I might be trying to reinvent the wheel here, but has anyone else thought of/tried this?
11-23-2003, 01:15 PM
#6
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You might be right, but if the gear come in contact with the case it will make a bunch of shavings. Would be bad if the pressure was high enough to make the filter bypass enable itself, or be stong enough to penetrate the filter.
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11-23-2003, 02:35 PM
#8
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With the buick/rover rv8 you are supposed to shim the cover plate by using suitable gaskets to give the correct gap. Few people do it and that's probably why the oil pressure is so low at idle. I reckon you've hit on a good idea and I'll take a look at it to.
11-24-2003, 01:06 AM
#10
Originally Posted by 2001CamaroGuy
the ported oil pressure is more than enough (I would think) but I'm just looking at how things could be improved more 
11-24-2003, 05:21 AM
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Originally Posted by Cal
If it's not broke, don't fix it! There are other things to turn your time and thought to, like how to put a bigger throttle body on an LS1 without a self-defeating reducer!
11-24-2003, 01:57 PM
#13
Originally Posted by Cal
If it's not broke, don't fix it! There are other things to turn your time and thought to, like how to put a bigger throttle body on an LS1 without a self-defeating reducer!
was your stock LS1 Camaro "broke" before you started hot rodding it....NO!! So why the hell did you mess with it? Answer: to make it BETTER!
if you just accept things "as is", then nothing better will ever come about
11-24-2003, 03:28 PM
#14
Originally Posted by 2001CamaroGuy
thats missing the entire point....
was your stock LS1 Camaro "broke" before you started hot rodding it....NO!! So why the hell did you mess with it? Answer: to make it BETTER!
if you just accept things "as is", then nothing better will ever come about
was your stock LS1 Camaro "broke" before you started hot rodding it....NO!! So why the hell did you mess with it? Answer: to make it BETTER!
if you just accept things "as is", then nothing better will ever come about
Last edited by Cal; 11-25-2003 at 11:09 AM.
