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.

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...

Gosh it's been a long time ago, but we used to just shin the spring. Kind of like the allison pump. I have no idea if that'll work in this case.

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.

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.

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.

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.

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.

This particular pump has 320,000 miles on it and shows no real signs of wear.

The way I see it we can possibly "tweak" our stock ones, or start from scratch and build a bigger, better pump.

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?

Spacer in the housing is not a viable option. Although 3/16" would fit in the pump housing itself, it throws fits with the reluctor wheel location and the pumps drive. Present pump gear thickness is .510.

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


Thanks!!

How much volume do you need to increase?

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.:(

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

Do we know how accurate the factoy guage is?

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

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.

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

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?

What about modding the piston squirters to open at lower pressure?

nwpadmax is working with "mapping" the squirter's right now to see just exactly how much PSI is needed to deliver the oil to the piston. Hopefully this will give us our baseline requirements.

I'm not trying to be a pain in the butt with questions, I'm just trying to figure out semi exactly how much more oil (press & volume) you need to accomplish this task.

To start with, IMHO, if the piston's oil cooling kicks out at 29 pounds then we should never EVER drop below that. It will take someone smarter than myself to form an estimate of how much more pump that might take. Some of our best mids are working on it though.;)

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

Of course....every bearing in the motor!

main bearings
rod bearings
cam bearings
turbo bearings
rocker shaft bearings
cooling jets

....I think that's it, did I forget anything?

What about modding the piston squirters to open at lower pressure?

An extreme appraoch would be to take the dang spring and ball out altogether, eh?

The rest of the bearings might get 'pissed off' though :D

Of course....every bearing in the motor!

main bearings
rod bearings
cam bearings
turbo bearings
rocker shaft bearings
cooling jets

....I think that's it, did I forget anything?


Smart a$$.):h):h
I meant whats different on the newer engines than the old ones??
Whats "leaking" more on them??

To start with, IMHO, if the piston's oil cooling kicks out at 29 pounds then we should never EVER drop below that. It will take someone smarter than myself to form an estimate of how much more pump that might take. Some of our best mids are working on it though.;)
I agree with all that's been said but if a person had a real guage on this & new an exact psi & dealing with a semi positive displacement pump & figure out how much more volume we need.

nwpadmax is working with "mapping" the squirter's right now to see just exactly how much PSI is needed to deliver the oil to the piston. Hopefully this will give us our baseline requirements.

He's not working cause he is reading the forum..........GET BACK TO WORK!

I agree with all that's been said but if a person had a real guage on this & new an exact psi & dealing with a semi positive displacement pump & figure out how much more volume we need.

Not doing anything real trick I did a simple test on my 06 LBZ and found that at 185 ECT we need to increase pump speed 66% in order to maintain 30 psi using 15W-40 Delo oil on a fresh filter and oil change. At warmer temperatures it's going to take more!

He's not working cause he is reading the forum..........GET BACK TO WORK!



:whip::whip:

Sounds like it needs 100% more pump. Can the housing be machines for bigger(thicker) gears?

We strap on second injection pumps, bigger turbo's, bigger injectors, etc.
Why cant we use an additional external oil pump?? Is there a place to plumb in into the motor? I am sure there is something I am missing here, but it seems like it would be a simple fix.

There is a leak down stream as compared to the LB7. We are pretty sure we know where it is but the problem is, if we post it and we are wrong then it becomes a major ordeal.

We are working to validate the senerio but the pump and relieve valve have nothing to do with it. If we are right, it will be a simple fix and require a small amount of work. The leak is there for a reason and we are trying to validate if it will cause damage that's why no posts are being made yet. I'm sure none of use want to be responsable for damaging someone elses motor. Give us a day or 2 to see if we are on the right track. No offence to anyone but after all the work I have put in, I sure don't want anyone else to damage a motor just trying something new. I'm sure Steve will validate it if he has time.

We strap on second injection pumps, bigger turbo's, bigger injectors, etc.
Why cant we use an additional external oil pump?? Is there a place to plumb in into the motor? I am sure there is something I am missing here, but it seems like it would be a simple fix.
If there is a good sorce to pull it out of the engine & place to plumb it back in would be the next thing.

he's not working cause he is reading the forum..........get back to work!

Yes Massa! :D

We need about 50% more volume. More is better. I spent some quality time with Mr Lance with the pump in pieces seeing if there was and easy way to boost the current pump, but no joy. Things are tight in the pump housing and on the engine. 30 % maybe, but 50 % is pushing it. A whole new pump will be required if you want to use the stock location.

But keep the ideas coming.

I spent some quality time with Mr Lance with the pump in pieces seeing if there was and easy way to boost the current pump, but no joy.
And as usual Jon, it was a Pleasure!:D

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.:(

Many types of racing venue use dry sump systems. It is much easier to manage oil pressure from never falling off. You don't have to worry about the oil leaving the pickup area or foaming picking up excessive air. There are very reliable electric pumps to manage this type of system that will deliver pretty accurate GPM.

All performance dry sumps are shaft driven off the engine. You would be hard pressed to get a 12 volt electric to supply the volume/HP needed.

there are a few external plugs on the outside of the block that go directly into the oil galley

All performance dry sumps are shaft driven off the engine.

You're correct.

The only way to increase volume is to increase the gear height. Then you have to increase the housing height. Then you're out of room. If you could manufacture thicker impeller gears and machine deeper into the housing, that would solve your clearance issues within the pan.

SB & BB chevy engines just used the taller housings/gears for higher volume. Clearance was not an issue with them provided you used the right pick up. Sorry I can't find a picture to post, but I think you guys can imagine what I'm talking about.

For high pressure, I just physically stretched the stock spring. I have a couple SB chevy 350s still running 55-60 psi with this method. I have seen the carnage of stacking shims (washers) to up the pressure. Cold, the plunger couldn't relief enough oil and pressures were pushing 85-90 psi at idle. result was stripping the teeth (heavy wear) on the cam gear that drives the oil pump (SBC). What can I say... I was 16 yrs. old and thought I was a genius. Now I'm only wise.

On edit... found the pic I was thinking of.

Even if you could create more flow, it won't solve the problem being addressed. Disproportionate oil flow. If the viscosity is not being controlled, the higher flow rates will just result in higher flow rates through the routes of least resistance (proportionately).

If you want to redistribute flow, put an obstruction in the path of abundant flow, or remove obstruction in the path of the shortage. Or just increase oil viscosity, it will net a similar result in this case.

Gotta ask. Why would more flow NOT increase oil gallery pressure? Which is the problem at hand.

Hi - I don't mean to jump in here unsolicited as I've got no credibility here, but King Pin asked me to take a look at this thread and see what I thought about it, having some experience with pumps, valves, orifices and all....

Let me make sure I understand what we're trying to do...

1)We've got a fixed displacement, fixed clearance, external gear pump driven by the crankshaft at some ratio.
2)There is a pressure relieving valve at the outlet of the pump, set to some pressure at a unknown flow.
2a) Can we get this relief valve setting, cracking pressure in particular (pressure where the valve first starts to open)
3)From here I assume it goes through the filter/cooler?
4)After the filter/cooler, it goes into a common passage with a bunch of leaks (bearings, lifters, piston cooling jets, etc)
5)The piston cooling jets have some sort of preset opening pressure (29 psi)? 5a)How do we know this opening pressure? Is it like a spring holding a ball on a seat with the nozzle that sprays on the piston after that - staying closed until 29psi oil pressure is generated?

The main issue is that the piston cooling jets don't stay open after letting off the throttle on a long hard run (since the engine RPM's drop and the oil is hot (low viscosity)) reducing oil flow/restriction to flow, therefore the cooling jets "shut off" thus allowing the piston to overheat?

I've got a handfull of ideas/suggestions, but want to make sure the above understanding is correct and have someone answer the above couple questions.

Its alot of reading but take a look at this thread here http://www.dieselplace.com/forum/showthread.php?t=151060 (its one of the stickies)

There is some good info on what nwpadmax and others have tested in relation to the oil squirters and such. Good stuff.

Your post may be unsolicited but your views and presence is more than welcome :)

:welcome: BTW

Gotta ask. Why would more flow NOT increase oil gallery pressure? Which is the problem at hand.

More flow would increase oil gallery pressure until the pressure relief spring is overcome and excess oil is allowed dumped back into the sump. A stronger spring (relief system), would give you more volume if the system was not bleeding off excess pressure to begin with.

I'm sure that I'm entering a discussion with people who know ALLOt more than me, but I've got to ask. If the real problem here is piston cooling at the end of a run it seems there are two fairly simple things that could help.
1 Add an oil accumulator. These are frequently used on circle track cars to help with oil starvation, and some turbo cars to provide oil pressure during spool down after shut off.
2 put the motor in neutral at the end of the run and raise the RPM to hold the oil pressure up.
If cost is no concern, a dry sump system could certainly cure the problem

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.

If the existing system is relieving to the sump, wouldn't that be lost volume? Increasing the pressure in this scenario with said heavier spring would (percentage wise) increase volume to the pumps peak volume. True, you could not get more volume beyond 100%.

Depends if the relieve or spring you are talking about is in the pump or in the galley.....and what pressure the one in the galley is set to open at. also it seems to have a low flow problem.

More flow would increase oil gallery pressure until the pressure relief spring is overcome and excess oil is allowed dumped back into the sump. A stronger spring (relief system), would give you more volume if the system was not bleeding off excess pressure to begin with.

We are not popping the reliefs. So more volume would allow us to maintain oil pressure. Reducing flow to some part or other would be foolhardy IMO.

The bottom line is there is a difference in the various year engines. Starting in 2003 the pressure dropped from the earlier years and the oil pump and relief valves have remained the same. Increaseing the volume of the pump will raise the pressure and keep the system feeding oil everywhere, but it will cost additional Hp to drive the bigger pump. The trick in my mind is to find where GM created the extra internal leak and see if we can change it back to the early model levels. Then the oil pressure problem would be gone.

The bottom line is there is a difference in the various year engines. Starting in 2003 the pressure dropped from the earlier years and the oil pump and relief valves have remained the same. Increaseing the volume of the pump will raise the pressure and keep the system feeding oil everywhere, but it will cost additional Hp to drive the bigger pump. The trick in my mind is to find where GM created the extra internal leak and see if we can change it back to the early model levels. Then the oil pressure problem would be gone.;)

Its alot of reading but take a look at this thread here http://www.dieselplace.com/forum/showthread.php?t=151060 (its one of the stickies)

There is some good info on what nwpadmax and others have tested in relation to the oil squirters and such. Good stuff.

Your post may be unsolicited but your views and presence is more than welcome :)

:welcome: BTW

Thanks for the welcome!

OK - I read all the posts in the link you provided (whew). There's some good info on this in there.

I agree with the others that finding the "leak" in the system that seams to be the cause of the reduced oil pressure will be key in resolving the issue easily. Next is figuring out why they changed what they did so we don't cause another problem by "fixing" this one.

A couple ideas on increasing oil flow if it turns out that we can't "fix" the leak in the newer engines...

1) Add an axuilary 12 Vdc oil pump capable of ~50+ psi
a) Have an outlet check to prevent loosing oil through the pump when engine oil pressures are higher than the ~40? psi we want to keep the piston squirters happy
b) Two pressure switches, one at the pressure where you want the pump to turn on, and another at the pressure where the engine pump has sufficient flow to maintain the pressure desired (40? psi?)
c) A simple latching logic circuit with a relay and the two pressure switches (one normally open, one normally closed) starts and stops the pump.
d) Pull oil from the sump or through a drain plug adapter and pump into the same gallery that the squirters are connected to.

2) Install a super duper oil cooler to keep oil temps down (anyone keeping an eye on oil temps?). Since we're dealing primarly with laminar leaks, we are very viscosity (and therefore temperature) sensitive.

3) Any increase in efficiency of the stock gear pump - primarly increasing the premiter coverage of the gear teath, maybe an insert, would help the pump maintain it's efficiency at low viscosities (high temperatures)

4) Can we change the drive ratio from the crankshaft to spin the oil pump gears faster?

Good luck!

I like ideas#3 & #4. I was hoping for a picture of the drive system to better visualize the feasability of a drive ratio change. Couldn't find anything by google.:o:

I personally have not seen the inside of a Duramax other than the pictures I've seen here. With used running motors going for $5,000+, I don't think I will have one to tinker with any time soon. Having worked in an automotive machine shop in the past, I'm quite familiar with the inner workings of a motor. This period in my life, with wife, kids, new house, etc., money is spent in those areas and the toys must wait. :( I can only sit on the sidelines and give suggestions from my past experiences. I applaud those who share their findings here because it affords me to learn without spending the thousands of dollars it would to experiece it first hand. Heck... I can't even seem to find the money to do my tranny. The wife raids the tranny fund quite often. Guess it's time to put my foot down!

Heck... I can't even seem to find the money to do my tranny. The wife raids the tranny fund quite often. Guess it's time to put my foot down!

Don't think you're the only one...:mad:

Fix_Until_Broken brought up a good point, what kind of oil temps are we typically seeing on these trucks?

Heck... I can't even seem to find the money to do my tranny. The wife raids the tranny fund quite often. Guess it's time to put my foot down!

or hide the fund ;)

So guys, where are we at on this oil pressure issue? Hasn't been an update post in awhile. Hopefully this is good news :) .

I think I have an equation figured out that will let us determine the theoretical displacement of the pump with a few simple measurements. Before I let this fly, I'd like someone to measure the center to center distance of the two gears in some semi-accurate manner. Thinking of a digital calipers, having the two gears installed in the housing, measuring from the outside of one shaft to the outside of the other, then subtracting one of the shaft diameters. This should give the center to center distance assuming the shafts are the same size. If this measurement is 2.864 inches then the equation should be good with just the tooth count and the thickness of the gears, if not, we'll have to go through the above process.

If the same kind soul could also measure the width/thickness of the gears, I'd also appreciate it.

Sounds like someone figured out that the reduction of oil pressure on the later engines is due to higher flow allowed to the turbo charger. We can start breaking down how much flow is going where if we know how much flow we've got available in the first place from the pump.

Thanks!

The gear width is .510. I'll try to get you a c-c tomorrow.:)

The gear width is .510. I'll try to get you a c-c tomorrow.:)


Any luck with the CC'ing?

If you are able to determine the radius on the teeth and the diameter of the gear, I can draw this in MasterCam, then analyze the volume. I can then add thickness to the gears, reanalyze, and determine what the additional volume is.

Are these parts Metric or English? .510" comes very close to 13mm.

Im not 100% sure, but 99% sure that All dimensions on this engine are metric.

Has anyone tried using a larger sump oil pan? More oil (say 15 qts. +), would take longer to heat up, lose viscosity, and cause the lower oil pressures after a hard pull. Just thinking aloud here.

What's the status anyway? there's been no activity on this thread for a while now.

i got flamed on here for wanting more oil pressure.now look.everybody wants more oil pressure.

i got flamed on here for wanting more oil pressure.now look.everybody wants more oil pressure.
Some people on here are into a little premature flaming!!!:D:D:D

i got flamed on here for wanting more oil pressure.now look.everybody wants more oil pressure.

Some people on here are into a little premature flaming!!!:D:D:D


It's not higher pressure they seek, it is higher volume to maintain the stock pressure. :)

It's not higher pressure they seek, it is higher volume to maintain the stock pressure. :)

Ding, ding, ding.;)

Sorry it took so long, but here are the rough measurements.

Outside gear dia is 2.044, and the valley dia is 1.241. The rad at the bottom of the valley is aprox. 5/64. Hope this helps.:)

Thanks Rick... Give me a few days and I'll post the findings / 3-D drawings here. The program is at work and I'm off 'til Friday.

The picture RickDLance posted shows a truck with oil pressure <30psi by the factory gauge after a long uphill pull with a heavy load. Since the pump is mechanical, the pressure should maintain as long as there is good supply. The pressure relief valve and squirter valves are all designed to ensure good pressure to the rotating assembly (presumed at least 29psi from the squirter pressure valve setting). The oil will be plenty hot at the end of a long uphill pull and that will lower oil pressure, but is it reasonable that the oil pressure will drop below 29psi due to hot oil alone? If not, then the problem may also arise due to poor draining back to the pan.

Not sure if this is right, but I thought it may be worth discussing.