Oil Flow.

[af300e]

Anyone have any educated idea on what sort of oil flow a 4 cyl toyota engine (3sgte specifically) has?

By flow, I don't want the flow rating of the pump, or the filter (although filter flow might be as close as I can get to a figure).
I'm after the actual return flow rate, that is, how quickly oil taken from the sump is returned to the sump. Or, if oil was pumped from the sump (of a given capacity) but not returned to the sump, how long it would take to empty the sump.
A max figure would be the most help, say at 7500rpm?

I'm happy to elaborate if nobody can work out what the fudge i'm talking about.

Thanks in advance.
Andrew

[Joshstix]

There will be no absolte answer as it is viscosity dependant. Not to mention depending on bearing clearances, engine mounting angle, oil return passages used, top end restrictors, windage control etc etc.

[af300e]

Fair enough, but I only need an idea. The clearances etc are probably not going to make so much of a difference that it might be 25 L/min or 100 L/min for a given motor. I just don't want to provide return flow of 100 L/min if I only need, even at max possible bearing clearance and min oil viscosity, 50 L/min.

In other words, a typical maximum flow at max revs would be fine. No need for pinpoint accuracy.

Am I making sense?

If someone had measured the flow on a sloppy motor running 10w-40 that would be fine, I just need an idea.

Has anyone measured or researched this?

[oldcorollas]

By flow, I don't want the flow rating of the pump, or the filter (although filter flow might be as close as I can get to a figure).
I'm after the actual return flow rate, that is, how quickly oil taken from the sump is returned to the sump. Or, if oil was pumped from the sump (of a given capacity) but not returned to the sump, how long it would take to empty the sump.
A max figure would be the most help, say at 7500rpm?

well... if you are not running out of oil, then the return rate must equal the pump flow rate..

on the last point, if oil was not returned to sump, then the time taken to empty the sump, will be the time taken for the pump to initially pump that volume, plus the time taken to pump the oil that was bled off by the pressure relief valve.

do you want to find the time it takes for a given bit of oil to get back after being pumped?
or the flow rate of oil down the side of the block and out of bearings around the crank?


edit: i would suggest that if you provide enough flow for the maximum possible flow from the pump, assuming there is no loss from the reliefe valve (and there will), then you will be safe.

[jimmmayyy]

in the first if any oil pump was pumping more than the return rate you'd be in for serious problems pretty quick.

easy way to work it, take out the oil pump, with an intake in a measured volume of oil, spin it up to the rpm you want then time how long it takes to move that volume. then get your calculator out.

measuring the return rate vs pump flow would be much more involved, and i'd be surprised if you find anyone with that information besides a toyota engineer. but hey, if you're that determined to figure it out then its still possible.. though difficult.

[LeeRoy]

Hook the pump up to a motor along with an oil pressure guage, the hold the engine at the desired RPM then decrease the speed of the oil pump. Watch the guage and when it drops youll have your answer.

[af300e]

Thank you all for your replies. I suspect my description of what i'm after needs tuning though, so I'll try to paint a better picture.

in the first if any oil pump was pumping more than the return rate you'd be in for serious problems pretty quick.

easy way to work it, take out the oil pump, with an intake in a measured volume of oil, spin it up to the rpm you want then time how long it takes to move that volume. then get your calculator out.

I expect the pump rate with the pump fitted to the engine to be similar to the total return rate which includes the pressure relief bleed-off.

Hook the pump up to a motor along with an oil pressure guage, the hold the engine at the desired RPM then decrease the speed of the oil pump. Watch the guage and when it drops youll have your answer.

Can you elaborate on this for me? You might need to talk me through it a bit more

Regarding testing with the pump removed, would this not just give the flow rate of the pump without load, rather than the flow rate with the pump fitted? Or will the pressure relief valve cause the two scenarios to have the same flow rate?
I'm assuming that because the pump will not draw more oil that it can force through the engine and pressure relief, that a pump that does not have to force oil through an engine will draw more oil. I can make my return handle this flow, but i suspect it might be huge overkill compared to actual flow when the pump is fitted.

OC, By having the oil not returned to the sump i mean the pressure relief bleed-off quanitity too.

Here's the actual application:

I have all oil returning to the sump through a central mini-sump which houses the pump pick-up. This mini-sump is gate baffled to prevent oil surge. I need to ensure that the overflow holes from the mini-sump into the main sump are sufficient to prevent the mini-sump overflowing and flooding the crank area. The pick-up can pull oil through the gates from the main sump, but the mini-sump level must be at the overflow holes before it bleeds off into the main sump. This might cause it to overflow if the bleed from the mini-sump to the main sump is not of a sufficient flow rate.

So, the quantity of oil flowing into the mini-sump will be equal to whatever the pump picks up. I'm assuming that this quantity will be less than the total free flow (as in bench tested) rate of the pump, and thus my need for an estimate/rough figure with the pump actually fitted. The overflow holes need to be large enough to accept this quantity plus an extra margin to allow for extra oil that has entered the mini-sump due to cornering/braking/acceleration forces.

I hope that explains it better. I should have mentioned the actual situation at the beginning.

Thanks again in advance.

[allencr]

Hello. I don't know what the problem is, but your cure sounds much worse.

This site may have a few things about oil flow that are usefull. It's URL=?????
http://www.google.com/custom?domains...D%3A1%3B&hl=en

[af300e]

Thanks for the link Allen. The consensus seems to be somewhere between 2 and 6 gpm. According to my research oil filters are tested at around 25L/min or 5.7gpm. I think if I allow overflow of 30L/min or so i should be safe.

Thanks again guys, if anyone has anymore info I'm happy to listen.

[oldcorollas]

I have all oil returning to the sump through a central mini-sump which houses the pump pick-up. This mini-sump is gate baffled to prevent oil surge. I need to ensure that the overflow holes from the mini-sump into the main sump are sufficient to prevent the mini-sump overflowing and flooding the crank area. The pick-up can pull oil through the gates from the main sump, but the mini-sump level must be at the overflow holes before it bleeds off into the main sump. This might cause it to overflow if the bleed from the mini-sump to the main sump is not of a sufficient flow rate.

So, the quantity of oil flowing into the mini-sump will be equal to whatever the pump picks up. I'm assuming that this quantity will be less than the total free flow (as in bench tested) rate of the pump, and thus my need for an estimate/rough figure with the pump actually fitted. The overflow holes need to be large enough to accept this quantity plus an extra margin to allow for extra oil that has entered the mini-sump due to cornering/braking/acceleration forces.

if i am reading that correctly, you want to have the oil basically flowing fromt he oil pump, around engine, back into mini sump, then picked up by the pump again..??

a few thoughts... what abotu the oil on the gated areas? when does that get picked up?

i am not sure that your idea abotu overflow are correct.
ie, the ONLY oil available to flow back to the sump, will be the oil pumped.. ie the flow of the pump will always be same, or maybe higher than the oil coming back. UNLESS you are slowing the engine down.
in that case, say, during decel and gear changes, you will have more return than flow. BUT it is a very dynamic system.

i am not sure why you are worried abotu the minisump overflowing so much. and i am not sure how this differs from a typical gated sump setup?
ie, unless your gates seal perfectly, then oil will leak from them to the side areas anyway. and being able to pull the oil from the side areas is better as then you are sharing the heat load aroudn the oil better..

in a normal gated setup, oil can be returned basically to the middle section, and then when cornering, the side oil is allowed to flow into centre via the gate... there may or may not be overflow holes above the gates, but there is no real need unless the side areas are sealed on top also (in which case they can only get oil into them via leaky gates?). usually the gates are low enough, adn there is a windage plate above also, so that even if oil goes over top of gate to side section, it won't get whipped up.... maybe?

what benefit are you trying to gain over a typical gated setup?
and regarding oil overflow rate from centre to side section.. that will only happen when engine speed decreases.. or where oil is kept in head or wherever by corenering G's...
the range of oil flow in dynamic system is quite large.. i would be tempeted to have a reasonable gap between the top of gates and the windage tray, to allow overflow during corenering, when the oil from the side area flows back under the gate...

[af300e]

i would be tempeted to have a reasonable gap between the top of gates and the windage tray, to allow overflow during corenering, when the oil from the side area flows back under the gate...

This is what I was getting at, I want to ensure that there is sufficient overflow capacity. I think I have it sorted though.

The baffle system in question is typical, but I have built it myself and, having not built one before, I'm trying to make an educated assessment as to how well it might work. I'm confident that the gates I've set up will be fine, they are large and low in the pan.
The final issue was that the mini-sump might overflow due to return volume combined with the effects of g-forces filling the mini-sump. I had suspected that max flow through the pump would be somewhere around 25 L/min and i've designed the system to cope with such a figure, I just thought it better to get some other's ideas on what flow might be. I've run a few tests and I'm happy with the way it has performed and I'm pretty sure it will have sufficient drainback to the main side sumps.

Regarding oil circulation in the sump, in a track application, the oil from the outer sump will be constanly forced in and out of the centre sump by g-forces. I can't imagine it having sufficient time to cool in the outer sump before it flows back into the mini-sump and is picked up by the pump.
In a road situation, well the car will hardly ever see public roads. For the few times it does I'm sure it will be fine.

Regarding the dynamic characteristics of oil flow, I understand that the flow will change and the suction/return relationship may also change, but I only want to make sure that I can cater for a maximum return situation. If the mini-sump overflow can handle the maximum return flow rate, plus a margin for safety then that's fine. That the pump is continuously pulling oil from the mini-sump only helps my situation, the fact that this suction/return relationship might vary is not an issue. I only need to make sure that it can cope with a maximum situation.

Thanks again for the input, the more ideas/perspectives you give me the more I think about it and that can only be good.

[rick q]

For what it's worth, I've been told that a 4AGE pump delivers 45 litres/minute at 8000rpm or thereabouts.

[af300e]

For what it's worth, I've been told that a 4AGE pump delivers 45 litres/minute at 8000rpm or thereabouts.

Is that free running (test bench without load) or attached to a motor?

[rick q]

Since it's a positive displacement pump, apart from leakage around the sides, that's what you'll get.

That's the main reason they have a pressure relief at the discharge of oil pumps [to relieve the excess flow] as, to a point, plain bearings are designed to work at a certain pressure of oil. The amount of leakage through all the bearings then sets the flow the engine needs - the rest shoots through the pressure relief valve.

[af300e]

Sorry, Rick, I meant, is that actually the flow delivered through the motor, or does it include the bleed off from the pressure relief too?