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Discussion Starter #1
Here it is Guys. Hopefully this will give you an idea what we're dealing with. Fingers and I spent a more than a few hours throwing stuff around, but nothing to talk about yet.

Anyone got any idea's how we can pick up this babies output?

On Edit;

For you guys that are just tuning in. Our goal here is to increase the oil flow out of the pump and to the underside of the pistons. We have hopes that this will help eliminate some piston failures.
 

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Are the pumps in the older, higher pressure engines of a similar design? Check the part numbers at the dealer for the spring in the low vs high pressure models.

In our chevy street stock class dirt track race car we went down to the chevy dealer and bought the spring for a performance engine oil pump, went to the shop and put it in our stock low perf. oil pump and went from 30 psi to 60. Your finger is pointing to it in picture 38104. The internal pictures don't look like a very high-tech or efficient pump! What does the drive look like on the front? Gear-driven from that loose nut in 38099?

First thing I would try...

Great job you are doing BTW! In all your posts!

Hmmm...upon more thought...I can't remember 15 years ago what happened with the oil pressure at idle. If I had to guess, I would think it did not change much...but it could have...that is quite a long spring, it could be moving over a large rpm range and regulating the oil pressure over quite a range. Sorry, just more thoughts to muddy the water...
 

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RickDLance;1734914; said:
Here it is Guys. Hopefully this will give you an idea what we're dealing with. Fingers and I spent a more than a few hours throwing stuff around, but nothing to talk about yet.

Anyone got any idea's how we can pick up this babies output?
TryAnyThingOnce suggested getting a replacement spring to increase pressure. This will only increase pressure; it will not increase flow. Its easy to increase pressure but that does not increase output from the oil pump. To increase flow you have to increase the pumping rate.

In the old days, on the drag strip, this same question was asked. Logic, testing and a decent understanding of hydraulics helps. You can increase pressure by pumping the same flow rate through a smaller hole but that will not increase output from the pump. The logical answer is to increase your flow rate by obtaining a high-output pump.


If the only thing you desire is higher pressure the spring will work but it will not increase pump output.
 

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The problem we are faced with is not a lack of pressure as when the oil is cool it makes 60+ psi. The factory relief valve in the pump is already set at 74 psi. We are short on volume in the LLY or LBZ motors unless we fix the internal leaks.
 

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Rick, because it's a positive displacement gear type pump, all of your pumping occurs in the two close-tolerance areas marked in yellow and the fixed volume of oil is that trapped in the "gap" between the teeth and the wall of the pump case in those areas. The only way to increase volume at the same speed is to resize the pumping zones. You could go with thicker gears, but that would require case modifications. My suggestion is to "deepen" the base of the gear teeth (where I've "red spotted" the gears) you could cut closer to the central shaft at each tooth root and that would increase the area of trapped oil that is "swiped" through the pumping zones. However, do not modify the "lobes" or outer section of the gear teeth, because that fit is critical in the center (red circle) to separate the low pressure and high pressures sides of the process.
 

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Idle Chatter, deepening the groove will not pump more oil because there is not a corresponding bigger tooth to displace the oil out of the groove. More oil will just travel around with gear.

Prof and Tech, I agree, unless the spring is allowing oil to start bypassing at a lower pressure, with an overall rating of 74 at maximum flow. Like I said before, that is quite a long spring in a long housing.

They wouldn't (would they?!?) add a leak downstream in the engine to lower the oilpressure. They would change the oil pump. If the housing, gears, and pump drive ratio are the same as the older one, the spring is different and bypassing oil at lower flow rates.
 

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Is this an old pump with degraded flow, or is a new pump that you're trying to improve.
I've seen several positive displacement gear pumps with degraded flow, (not engines). These pumps had been in service after many years. Reduced flow will develope reduced outlet pressure.
These pumps when disassembled had noticable wear in the side of the case next to gears, and oil could bypass around the gears, to reduce output flow.
 

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pump volume

Idle chatter has one one plan, also if space permits you can make a spacer to seperate the two halves let's say 1/4'' & have someone machine new gears 1/4" thicker. Depending on present gear thickness your pump volume should be quite an increase. How much volume do you want for an increase?
 

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volume

How much volume do you need to increase?
 

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King Pin;1735206; said:
How much volume do you need to increase?
I'll let the "experts" answer this one, but basicly we are trying to insure that the underpiston oilers never shut off. They are preset at 29 PSI IIRC. The picture below was taken right after a heavy pull up a long hill on a low mileage 05. Shortly afterwards this truck cracked a piston.:(
 

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just a little fyi. race my truck last night, made 2 passes with the big stuff. oil pressure didnt budge at all. running syn amsoil 15w40. will be switching to the new 07 amsoil 5w40 and trying that next weekend
 

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???????

Do we know how accurate the factoy guage is?
 

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thinking out loud here, but does it matter. when warm at idle, i can rev it up and it moves right along with it, not much delay. i would think that any drop in pressure i would of seen, not that it has to be at XX, but it didnt move from XX. i have always heard about loosing pressure at the end of the run, but don't appear to see it on my truck. but than again, its and 02
 

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TryAnythingOnce;1735095; said:
Idle Chatter, deepening the groove will not pump more oil because there is not a corresponding bigger tooth to displace the oil out of the groove. More oil will just travel around with gear.

Prof and Tech, I agree, unless the spring is allowing oil to start bypassing at a lower pressure, with an overall rating of 74 at maximum flow. Like I said before, that is quite a long spring in a long housing.

They wouldn't (would they?!?) add a leak downstream in the engine to lower the oilpressure. They would change the oil pump. If the housing, gears, and pump drive ratio are the same as the older one, the spring is different and bypassing oil at lower flow rates.
The oil is not displaced by the tooth mesh, the tooth mesh prevents excessive "slippage" back to the low pressure side. The outer fit indicated in the picture is continually delivering oil to the high pressure side and more volume delivered means more volume discharged (the oil seeking the path of least resistance out of the pump housing). The speed of rotation tends to "sling" the oil in the tooth-gap/casing fit when clearances open after the pumping.
 

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The factory gauge is pretty good above 30 psi and not so good below 30 psi.

TryAnythingOnce
"They wouldn't (would they?!?) add a leak downstream in the engine to lower the oilpressure"

Thery sure did as the oil pumps are all the same from '01 - '07
 

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Diesel Tech;1735284; said:
The factory gauge is pretty good above 30 psi and not so good below 30 psi.

TryAnythingOnce
"They wouldn't (would they?!?) add a leak downstream in the engine to lower the oilpressure"

Thery sure did as the oil pumps are all the same from '01 - '07

Have you figured out where the "leak" is yet?
 
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