Rb26 Oil Pump Choices

[tk80]

At what power do you HAVE TO upgrade the pump? 350rwkw, 400rwkw?

At what stage will one of these upgraded pumps empty the STD sump?

Asked another way... Will a well balanced 400rwkw (ati balanced etc) motor cope with hard track work with a STD pump for a long period of time (years)?

And secondly....will an upgraded pump empty the std sump on the track of a 400rwkw motor?

Edited March 29, 2011 by tk80

[R31Nismoid]

1. There is no set figure. However 380rwkw track cars down here have been fine (OP's aim).

2. Well it shouldn't ever empty it if returns and so on are all working... But read below.

So the other way

400rwkw, no reason why a N1 pump won't be upto the task. Been done on many occasions before without a problem.

400rwkw is generating a lot of heat though. For sanity sake some extra volume of oil would be a good idea to keep temps and oil life in better stead without a doubt. Kinda why i posted up a possible "Option 1.5" even though it wasn't listed first.

[Nee-san]

Used an N1 oil pump for a year on my built 26.

Never lost pressure, never missed a beat, just make sure you get a ridgey didge one (nissan)

And mind you, at the time it was running, the pump had had probably a 2 inch chunk smashed out of it, plus damage to the sump which had been badly bogged up, and still worked.

Sent car to workshop to fix it all up, put new N1 Pump on it.

now shooting for 400AWKW.

Running big oil cooler for extra volume and cooling capacity

Edited March 29, 2011 by Nee-san

[Beer Baron]

sorry but I don't agree with nismoid. yes an aftermarket pump WILL empty the sump. it's a bloody simple equation. how much can the pump flow in 1min of operation at XXX RPM. then look at how much oil can pass through the oil galleries in that time (it's much less, only gravity to help it). it's a dangerous thing.

a nitto pump will flow 64.8 litres per minute, that is 1.1 litre per second. now with only just on 4 litres in an RB26 sump it will take just 4 seconds at 7,000rpm to empty the sump of oil. but in that 4 seconds of running the engine may return 1 litre of oil through the oil galleries to the sump. so after 4 seconds we have 1 litre in the sump, another second sees another 1.1 litre pumped up, and sees another 250ml return, so you could easily see that after about 6 seconds of 7,000rpm+ running you no longer have a drop of oil in the sump. add to that, that you are pulling some accell G at this moment meaning oil is away from the pick-up then in reality things probably go wrong a bit sooner.

note, the figure of 1L per min of oil returning through the stock head and block galleries is just a random number, it's been roughly calculated before at a given viscosity of oil how much can get in there, but it varies a bit depending on vacuum/pressure conditions in the crankcase etc too. but that's around what it is. even if you double it, things won't go much better.

all this basically tells us is that upgrading the oil pump with a standard sump is a bad idea. If you are adding 30% to what the pump can flow (and adding nothing to how quickly that oil can return), then you should be adding 30% to the sump capacity too.

as far as what power do you have to upgrade? There is no set figure, but I will say this. most of the circuit cars I've been invloved with were fine at 350kw on semi slicks. once they hit 380, 400kw etc on new semis (and with good drivers) they suddenly started having oil system problems all the time. it's just too much power, too much G force and not a good enough system. of those guys, the ones that went to dry sump systems now live happily on the track at 450kw+. honestly I reckon if you have that much power in a track car you should have the brakes to go with it ($10K+), the safety gear to go with it (full cage) and the right oiling system to protect that 450kw engine (dry sump, cost around $8-$10K.).

[Supa Steve]

sorry but I don't agree with nismoid. yes an aftermarket pump WILL empty the sump. it's a bloody simple equation. how much can the pump flow in 1min of operation at XXX RPM. then look at how much oil can pass through the oil galleries in that time (it's much less, only gravity to help it). it's a dangerous thing.

a nitto pump will flow 64.8 litres per minute, that is 1.1 litre per second. now with only just on 4 litres in an RB26 sump it will take just 4 seconds at 7,000rpm to empty the sump of oil. but in that 4 seconds of running the engine may return 1 litre of oil through the oil galleries to the sump. so after 4 seconds we have 1 litre in the sump, another second sees another 1.1 litre pumped up, and sees another 250ml return, so you could easily see that after about 6 seconds of 7,000rpm+ running you no longer have a drop of oil in the sump. add to that, that you are pulling some accell G at this moment meaning oil is away from the pick-up then in reality things probably go wrong a bit sooner.

note, the figure of 1L per min of oil returning through the stock head and block galleries is just a random number, it's been roughly calculated before at a given viscosity of oil how much can get in there, but it varies a bit depending on vacuum/pressure conditions in the crankcase etc too. but that's around what it is. even if you double it, things won't go much better.

all this basically tells us is that upgrading the oil pump with a standard sump is a bad idea. If you are adding 30% to what the pump can flow (and adding nothing to how quickly that oil can return), then you should be adding 30% to the sump capacity too.

as far as what power do you have to upgrade? There is no set figure, but I will say this. most of the circuit cars I've been invloved with were fine at 350kw on semi slicks. once they hit 380, 400kw etc on new semis (and with good drivers) they suddenly started having oil system problems all the time. it's just too much power, too much G force and not a good enough system. of those guys, the ones that went to dry sump systems now live happily on the track at 450kw+. honestly I reckon if you have that much power in a track car you should have the brakes to go with it ($10K+), the safety gear to go with it (full cage) and the right oiling system to protect that 450kw engine (dry sump, cost around $8-$10K.).

Mate you obviously have some experience with these cars other than with a keyboard and screen in front of you. Anyone who thinks they can reliably track these cars with an N1 pump is a fool and also tracking one with a Nitto/JUN/Tomei using a stock sump is also. Nismoid only tells half the story as when i had a lengthy chat to Racepace about building me an engine there were little things like enlarged oil drains and wider rod bearings etc that were mentioned. Racepace build the engine to suit the pump but to suggest on here that others can blindly fit one is like saying a snake charmer can play a flute to a cobra and not get bitten so they must not be deadly.

Red R have an engine at their shop to fix that was built in Brisbane that has bent a 30 crank 4mm after 2 laps of Queensland raceway because they tried using a Nitto pump with a stock sump. They have also ran an N1 pump harder than most early in the piece in their drag car that survived hell for 3 years but again this is a properly built and prepared engine.

Unless you have guys who know how to build around the pump like Racepace, Red R etc. id steer clear of the N1 timebomb.

Edited March 30, 2011 by Supa Steve

[djr81]

Well if it help here is a photo (from Serge at NextGen Photography - he does awesome work) and a data log. Trim puckering moment at about 176 seconds when the thing spat sideways on the exit of the chicane at Collie. Which may or may not have been shortly after Serges photo.

For what it is worth none of the options I listed teamed a high volume pump with a stock sump. For the very reasons teh Baron explained.

The hard part is, as ever, deciding how much is enough. There is no data and can be none on how much flow is sufficient. For what it is worth I think I will be going a Tomei pump & larger sump. Just hope the people at Visa understand.

Run 2.pdf

[bubba]

The enlarging of the oil drains and bearing feeds is something most often overlooked.

[Nee-san]

Just OT but,

How does that PWR cooler go ?

[R31Nismoid]

Rich - it's not simple maths at all. Go and include restrictors & flow, then try again.

Mate you obviously have some experience with these cars other than with a keyboard and screen in front of you. Anyone who thinks they can reliably track these cars with an N1 pump is a fool and also tracking one with a Nitto/JUN/Tomei using a stock sump is also. Nismoid only tells half the story as when i had a lengthy chat to Racepace about building me an engine there were little things like enlarged oil drains and wider rod bearings etc that were mentioned. Racepace build the engine to suit the pump but to suggest on here that others can blindly fit one is like saying a snake charmer can play a flute to a cobra and not get bitten so they must not be deadly.

Red R have an engine at their shop to fix that was built in Brisbane that has bent a 30 crank 4mm after 2 laps of Queensland raceway because they tried using a Nitto pump with a stock sump. They have also ran an N1 pump harder than most early in the piece in their drag car that survived hell for 3 years but again this is a properly built and prepared engine.

Unless you have guys who know how to build around the pump like Racepace, Red R etc. id steer clear of the N1 timebomb.

Steve/Paul, whoever is using the account. I'm not telling half the story @ all.

djr has already made mention of restrictors and so on. Also assuming drains are enlarged as well and no need for silly external drains that are the latest "fad" that everyone seems to need - but never has before strangely enough.

There are more cars here running N1 pumps in circuit cars than there are Tomei/Jun etc. I guess everyone is a fool... But all are reliable fools, so proof is always in the pudding. I go on results and hard evidence, not hearsay or people unwilling to admit they broke their pumps to due abuse or tune.

[FineLine]

And another N1 victim.

http://www.skylinesaustralia.com/forums/topic/359111-rb30-failure/page__pid__5737962#entry5737962

[GTRNUR]

Does anyone know conclusively what causes the pumps to fail, or is it mostly guesswork and hearsay?

The only possibility that comes to mind is that if the crank is wobbling side to side (and up and down) at the pump end, that at a certain point in its rotation the crank drive collar might lean (hammer)on the inner gear with sufficient force that it is striking the outer gear which is hard up against the pump housing. What starts as a hammering eventually creates a crack in the inner gear.

So you’d have to be pretty unlucky to have one fail, but what would make the probability that it could happen worse would be loose main bearing clearances combined with a poor balance on the crank, flywheel/clutch and harmonic balancer.

To me this also makes sense why the Tomei pumps tend to survive a little better. It wont just be the metalurgy, but also the splined drive in the pump gear allows for a little more movement. It would be interesting to see how tightly the drive spline on a 2JZ holds onto the crank. Im guessing there is a fair amount of play, enough to tolerate ~4 thou of movement.

Im really just guessing though...

[FineLine]

From what I understand there are a couple of issues. The earlier model pumps were a better pump than the later stuff, be this by virtue of inferior materials or what i dont know,

The other issue is rev limiter bashing. It creates a backlash on the gears to the point of failure.

Wiser heads than mine may have better reasons but that is my understanding of the issues.

[Scooby]

OK not sure if I've missed something but I've never heard of a stock RB26 pump failing. If it's the case that they don't, why not run an enlarged sump,oil restrictor and stock pump?

[webber]

I have to update my list, as i have a bit more information to add to it & pics, BUT

check it out HERE 90% of information is from manufacturers websites. So i don't give a shit if You have a blah, blah pump and it has blah, blah pressure at blah blah revs. I don't care. On my site i don't have to please anyone else i just thought i would share. If anyone can fill in some more blanks, then i am listening

[XRATED]

Nice write up Webber...

Also, flow rate will slow as pressure in increased.... eg more pressure/restriction= less flow. Flow rate would be decreased by the time the oil is pushed through oil galleries, bearing clearances, restricters, relief valves, oil squirters etc...

I find it very hard to believe the flow figures provided are at working pressure and through working outlets.

At the end of the day, it's a fixed displacment pump, with a pressure relief valve... the smaller the outlets, the sooner the relief valve opens and the more oil is bypassed.

Cheers

J.

[XRATED]

A spline drive collar and inner oil pump gear would be ideal... I chipped in for a set for manufacture by one of the guys on the forum last year, unfortunately it didn't happen....

I firmly believe, an Aussie company would make a killing by manufacturing a spline drive collar and inner gear oil pump set... Especially with a well proven product like Nitto... hint hint.

J.

[djr81]

Nice write up Webber...

Also, flow rate will slow as pressure in increased.... eg more pressure/restriction= less flow. Flow rate would be decreased by the time the oil is pushed through oil galleries, bearing clearances, restricters, relief valves, oil squirters etc...

I find it very hard to believe the flow figures provided are at working pressure and through working outlets.

At the end of the day, it's a fixed displacment pump, with a pressure relief valve... the smaller the outlets, the sooner the relief valve opens and the more oil is bypassed.

Cheers

J.

I think the flow rate quoted for the stock pump is wrong - it should be 46L/min at 6000rpm.

Also the outside diameter of the outer rotor of the stock pump is larger than the N1 pump so you need to be careful what you are referring to.

Oil pumps of this type are POSITIVE displacement pumps. Flow rate out of the pump is not linked to pressure. The bypass valve is what needs attention. Oddly enough it is what no one pays any mind to.

Edited March 31, 2011 by djr81

[bubba]

A spline drive collar and inner oil pump gear would be ideal... I chipped in for a set for manufacture by one of the guys on the forum last year, unfortunately it didn't happen....

I was going to be a guinea pig for those, to my designers mind, the theory was so sound I felt extremely comfortable being the first to try it. Alas, shane apparently got ripped off and the whole thing fell in a heap

I can model up a design (based on the dimensions of the N1 pump I have in pieces at home) but I do not have the contacts or the time to be sourcing materials and manufacturers.

[bigmikespec]

If someone donates a set of pump gears and a junker crank I will do all design work and get quotes.

[The Dan]

I have already got design drawings for the N1 profile as I make the billet gearsets for the factory pumps but I agree that the spline idea is worth trying. I have a very reputable wire cutter that can cut any drawing you want to absolute perfection (as a spline will need to be wire cut, not CNC machined I believe)

If anyone wants to have a crack at it and talk to the wire cutter for quotes, I would be happy to sell the drawings already digitised and ready to go in the correct format. I say sell as I had to pay a fair bit of money in set up fees and digitising.

Shane (I think) still has the drawings for spline drive too but they may still be at the old dodgey machinist that he was going through.

I can also lend a doner collar made by our machinist.

I just lack the time and motivation after trying to sell the normal billet gears. They don't sell like hotcakes, I can tell you that