(pics) 3900 and 3500 oilpump comparison

[geoffinbc]

Pumps can only produce oil flow, NOT pressure.

Finally someone who gets it!

I will agree that if you are setting up a loose motor you may need more flow. But with a 3900 pump already flowing more than a 3400 or 3500 pump I don't think a DOHC pump is necessary.

If you are going for 7500 RPM then a high pressure spring may be in order since the stock one will bypass at about 55 to 60 PSI. Running 7500 RPM will require pressure around 80 PSI (if you follow the 10 PSI/1000RPM rule) and I believe that even with a loose motor you will still only need a stock pump. But if you want to increase the volume then take small steps, don't just buy the biggest pump that will work.

[Driver_10]

Finally someone who gets it!

I will agree that if you are setting up a loose motor you may need more flow. But with a 3900 pump already flowing more than a 3400 or 3500 pump I don't think a DOHC pump is necessary.

If you are going for 7500 RPM then a high pressure spring may be in order since the stock one will bypass at about 55 to 60 PSI. Running 7500 RPM will require pressure around 80 PSI (if you follow the 10 PSI/1000RPM rule) and I believe that even with a loose motor you will still only need a stock pump. But if you want to increase the volume then take small steps, don't just buy the biggest pump that will work.

Quite true.. However, I am also modifiying the block for oil-jets. My LX9 come stock with only one set of jets on the rear two cylinders. Seeing as the VVT3500 oil-pump supports 3 sets of oil-jets stock, I figured that it would be the perfect candidate.

[gectek]

i would not say what you are saying really. i am not speaking from just a whole in my head.

i will give you the experience that the LS engine world has provided to me. the normal LS engines are standard cam style like the 3400 and early 3500. the later styles are VVT. some people thought that because the VVT required more oil (due to some of them now also having the piston squirters) that they could use them like a performance pump for their engines withough VVT but maybe with piston squirters added (maybe not). in either case, that pump was just entirely too much for the engine. all types of catastrophic faillures occured including oil sump starvation, oil aeration, bearing wash, oil pump seizure, excessive leaking from oil seals. those are just a few. one guy even had a piston hit a valve due to high rpm and bearing wash causing the rod to lift, the bearing hit the rod, and it ruined the entire engine.

just my .02

[Driver_10]

i would not say what you are saying really. i am not speaking from just a whole in my head.

i will give you the experience that the LS engine world has provided to me. the normal LS engines are standard cam style like the 3400 and early 3500. the later styles are VVT. some people thought that because the VVT required more oil (due to some of them now also having the piston squirters) that they could use them like a performance pump for their engines withough VVT but maybe with piston squirters added (maybe not). in either case, that pump was just entirely too much for the engine. all types of catastrophic faillures occured including oil sump starvation, oil aeration, bearing wash, oil pump seizure, excessive leaking from oil seals. those are just a few. one guy even had a piston hit a valve due to high rpm and bearing wash causing the rod to lift, the bearing hit the rod, and it ruined the entire engine.

just my .02

Im installing oil-squirters into my block. The stock, "non-vvt" 3500 pump only accomodated the one set of jets at the rear of the block. With the addition of two more sets of jets, I will need to at least match the flow-rate of the VVT3500.

Dont need anymore than that and DEFINITELY need no less.

[gectek]

read please

some people thought that because the VVT required more oil (due to some of them now also having the piston squirters) that they could use them like a performance pump for their engines withough VVT but maybe with piston squirters added (maybe not).

this means that in either case if the engine did not have VVT whether the squirters came in the block, were machined into it later, or had none, the result was the same.

we talked with melling personally, and they let us know the 411. if you still choose to ignore fact, then that is fine. i am not trying to make you upset, but if you build it, i would like to see it live.

[91LQ1Lumina]

Just so I have a handle on what your saying. The VVT portion of my LZE is what needs the larger pump, and since my plans are to remove or disable the VVT. Should I then consider downgrading this oil pump before I ever consider using this engine?

[gectek]

i would look at that yes

[AaronGTR]

If oil pressure is low at part idle and drops considerably at high rpms, then excessive sheering is the most likey cause. Had his pressure been low yet stable from 2000-redline, then I would diagnose the pressure relief spring.

You have to remember that an engine's oiling system is a regulated "oil-leak". The looser that an engine gets over time, the more oil will "sheer" away and leak off at the clearances between the berrings.

You can shim a pump much to your heart's desires and still not get adaquate oil-pressure IF there isnt enough flow passing through the clearances to form restriction and build pressure.

Pumps can only produce oil flow, NOT pressure.

I HIGHLY doubt oil sheer is the problem as well, but there's no real way to tell without tearing my engine apart and checking the bearing clearances is there?

Anyway, my engine only has 58k miles on it. Not much. I've had the pressure gauge installed since 25 or 30k miles or so and had no valve train or other internal engine mods at that time that would possibly contribute to extra wear. It hasn't changed over time that I've noticed either... just always been low. It's hard to tell exactly what the presure is because it's a narrow sweep gauge. I'm thinking of getting a new gauge with a better scale and a new sender so I know it's working correctly and I can get a better reading. Then I'll see where I go from there.

[Driver_10]

Ooooohhhh... gectek was saying that its the VVT portion that requires the additional flow. That makes his arguement a lot more plausible.

However, the VVT actuator couldnt possibly use as much oil the oil-jets do. At 7500rpms with loosened clearances, turbo oil-feed and 6 squirting oil-jets, thats gonna add-up to quite a bit of required flow.

(ps sorry about sounding "stand-off'ish" before)

[Driver_10]

I HIGHLY doubt oil sheer is the problem as well, but there's no real way to tell without tearing my engine apart and checking the bearing clearances is there?

Anyway, my engine only has 58k miles on it. Not much. I've had the pressure gauge installed since 25 or 30k miles or so and had no valve train or other internal engine mods at that time that would possibly contribute to extra wear. It hasn't changed over time that I've noticed either... just always been low. It's hard to tell exactly what the presure is because it's a narrow sweep gauge. I'm thinking of getting a new gauge with a better scale and a new sender so I know it's working correctly and I can get a better reading. Then I'll see where I go from there.

Based on your symptoms, thats the only evaluation that I can come up with. Unless theres some sort of internal oil-leak, I cant think of any other culprit.

Without proper evaluation of the rotating assembly, you cant be sure of the engines internal condition. Just because its a 58k engine doesnt garrantee its condition.

You did find evidence of excessive berring material in that oil-sample analysis, did you not?

[gectek]

im saying even engines that we have built for high perf setups of over 800 hp have tried to use the vvt oil pump, even with the oil squirter being machined into the block exactly like you are doing and they ran into problems just like i said. they thought it was worth it too....in reality it was not and it cost them an engine. anytime we build an engine, doesnt matter if it has loose clearances or not, we do not recommend high volume unless the engine is race only. by race only i mean its going to live its entire life on the track. no daily driving, nothing. on a road race car, i would def not recommend a high volume pump. oil starvation + high g's in the corner = bad juju

[AaronGTR]

Based on your symptoms, thats the only evaluation that I can come up with. Unless theres some sort of internal oil-leak, I cant think of any other culprit.

Without proper evaluation of the rotating assembly, you cant be sure of the engines internal condition. Just because its a 58k engine doesn't guarantee its condition.

You did find evidence of excessive bearing material in that oil-sample analysis, did you not?

No they didn't mention anything related to bearing material in their report. They can tell if the metals present point to that. They said the silicone content was lower than last time but the oil had less miles on it than the last test so that doesn't mean much. I replaced the rockers and pushrods after the last test so I had the engine apart and they said the engine work could be responsible for the silicone levels from sealants etc. Otherwise it could be dirt getting in the engine and contributing to wear. Higher than average aluminum content could be from the rockers they said as well. Copper levels were higher than average which they said could be from something in the supercharger. Iron was also slightly high, everything else was close to normal. So silicone, aluminum, copper, and iron. I wonder if any of this could be from my oil pump drive gear?

im saying even engines that we have built for high perf setups of over 800 hp have tried to use the vvt oil pump, even with the oil squirter being machined into the block exactly like you are doing and they ran into problems just like i said. they thought it was worth it too....in reality it was not and it cost them an engine. anytime we build an engine, doesnt matter if it has loose clearances or not, we do not recommend high volume unless the engine is race only. by race only i mean its going to live its entire life on the track. no daily driving, nothing. on a road race car, i would def not recommend a high volume pump. oil starvation + high g's in the corner = bad juju

I get what you are saying there and it certainly makes sense. One thing I would point out though, if you were using the engine in a road race car and it really was a dedicated race engine, you should still be able to use a HV pump if the oil system is built properly for raod racing. IE a high capacity pan with baffles or a dry sump system... you wouldn't have to worry about oil slosh and pump starvation. Of course, that doesn't really apply to anyone here. As with anything it's a matter of choosing the right components for the engine's intended purpose rather than just trying to go overkill on everything.

[Driver_10]

im saying even engines that we have built for high perf setups of over 800 hp have tried to use the vvt oil pump, even with the oil squirter being machined into the block exactly like you are doing and they ran into problems just like i said. they thought it was worth it too....in reality it was not and it cost them an engine. anytime we build an engine, doesnt matter if it has loose clearances or not, we do not recommend high volume unless the engine is race only. by race only i mean its going to live its entire life on the track. no daily driving, nothing. on a road race car, i would def not recommend a high volume pump. oil starvation + high g's in the corner = bad juju

I am not being a sceptic or a smart-ass. Right now I am as serious as cancer...I want to be absolutely clear when I write this, so please read carefully.

Im assuming correctly then that this is PROVEN science and not mere hypothesis.

You are stating that you have INDEED assembled 60 degree motors , (NOT an LS1 or some other motor besides a 660) with oil-jets and 3500 VVT pumps that have failed because of excessive oil-pressure. If that, and none other, is the case then....

*ahem*...Have YOU had success running an "oil-jet" modified, high-output, high-rpm, 60 degree v6, motor with a stock pump with shimmed oil-relief springs in a daily driven car

If you have an accurate answer for this that is based on an actual, "real-life" example, then I will personally name my first born in your honor.

(Im am being as sincere as I can without septicism. Youll have to excuse the interogation. But I need an absolutely clear answer to this question)

[SappySE107]

Oh but you don't want to sound stand offish? Get real. Do what you want and tell us what it does. You can be certain no one here has an 800hp 60V6.

[Driver_10]

Oh but you don't want to sound stand offish? Get real. Do what you want and tell us what it does. You can be certain no one here has an 800hp 60V6.

His claim was so bold that Im sincerely curious.

If he says his shop has built some high-output 660s with oil-jets and so-forth, then I will give him the benifit of the doubt.

I have my own theories BUT, Im sincerely awaiting his reply. I really want to hear, whether bullshit or honest truth, what he has to say.

Who knows, I might just learn something new.