N1 Oil Pump Killed My Engine .....

[Abo Bob]

Where's Merli?

[CruiseLiner]

i had my brand new jun pump crack the inner gear but luckily i spotted it when the block cracked and engine was apart and i was cleaning the inside of it. $1200 down the drain the front harmonic balancer bolt had come slightly loose and obviously causing balancer to slide up and down the crank nose and the crank nose got sooo hot it welded the balancer str8 onto the nose and expanded the nose enough to crack the inner oil pump gear all this after 1200km of use.

another 10 min running and it may have shot a rod through the block and damaged the jun crank etc so i was extremely grateful i found it when i did.

[Sydneykid]

Just in case some of the readers haven't read and/or can't find the big oil pump thread, this is what I posted;

we have used 30+ N1 oil pumps over 5 years and not broken one. So I am very interested in getting to the bottom of why you have had 2 failures. I don't believe it is simply a case of you having been extremely unlucky or we have been unbelievably lucky. There must be a reason why we don't have problems, something we are doing different. Maybe not something obvious, maybe nothing to do with the oil pump itself.

So what I would like to do is list what we do and see if it is any different to what you did;

1. We always use a wide oil pump drive flange crank (late RB26) or a crank collar on RB20/25/30 cranks.

2. We use all sorts of different harmonic balancers, mostly standard RB26, but some RB30 and ATI.

3. We balance (to very fine tolerances) every up & down and round & round piece. Firstly individually and then as a group. This includes the harmonic balancer, the flywheel, the clutch plate/plates and the pressure plate.

4. All of our engines have oil surge prevention sumps, usually wings, baffles and one way doors.

5. We prime the oil pump on assembly

6. We are very particular about the torque of the harmonic balancer retaining bolt, and we insist that the tension is checked once the engine has been run for 20 minutes.

7. The blocks have the usual oil restrictor flow limits, various depending on the vehicle usage pattern (rpm limit, circuit, drag, road use etc).

8. All engines run oil coolers, most (but not all) run remote oil filters.

9. We insist on an oil filter change at 20 minutes running from new.

That’s about all I can think of that is remotely linked to the oil pump.

The reason for the N1 oil pump selection is for the extra pressure without excessive oil flow. Despite all of the oil return mods and upgrades (inc external return lines) we have found the aftermarket (HKS, Jun, Apexi, Trust etc ) oil pumps simply have too much flow. Plus they cost almost as much as a dry sump pump. So we never use them.

Do I detect a common difference? High rpm and lots of rev limiter controlled launches. We don’t do that many launches, one per race, so 24 per year, plus a few practise launches. With only light use of the launch control rev limiter.

It could also be related to the crank moving inside the oil pump rotor, like a hammer effect. That would be very noticeable on the rpm limiter, like a jack hammer.

What sort of clearances are you running on the oil pump drive flange? I know on at least one crank we have to weld up and regrind the flanges, as they were worn. A couple of other cranks were rejected as they were too far gone. The crank collar (for RB20/25/30) has a much smaller clearance than the “standard” RB26 flange. It is actually a very snug fit.

Cheers

[2rismo]

It cant be helped if your doing limiter launches and massive RPM burnouts all the time...which isnt street driving either.

It isn't?

[2rismo]

would you guys know where i can grab the video of that nascar road rage??

http://www.break.com/index/drop_kick_nascar_fight.html

[R31Nismoid]

It isn't?

ok, excluding a certain hoon from NSW

:sorcerer:

[Swiper the Fox]

i have also killed to n1 pumps!

it appears from my experience (which is limited) to be the type of application that you use your car for,

there is another thread on this somewhere? if drag racing your car and your harsh ignition cuts or launch control it does seem to play apart in breaking the oil pump gears. mine failed with rally use but we also were using lots of launch control and heaps of launches. some circuit cars would not see the problem as they do not launch them anywhere near as often.

also i now use a tomei supplied by high octane as it has been great, no issues at all and cost a lot lessthan a very damaged engine as we also found out. you must remember though that these pumps also pump a lot more oil and require big sumps and lots of oil return or you will end up hurtingthe engine anyway or spitting it all out the breather, especially if your doing pleanty of above 6000 rpm driving.

cheers russ

spot on beer baron

Post of the thread...

our N1 lasted nearly 3 years of abuse with a soft cut (fuel cut) rev limit and 8000- 8500rpm rev limit....used hard cut (ign cut) and 9000-9500rpm rev limit and it failed on the second pass.

campbell...you use a DIS-4 ignition system and you use this to control rev limit...very hard on N1 pumps.

did you immediately shut down after pump failure?? as a quick shutdown should have "caught" the engine and saved it any damage....i use two relays to shut off ignition and fuel in the event of low oil pressure and/or oil pump failure, instant shutdown saves $$

[frankxinyu]

a lot of useful information here for my development of the car...

Campbell, i can feel the pain man, very sorry to hear!!!! best of luck....

[FSTR32]

Hey cambell...Do you think possibly your MASSIVE burnout on the video you posted a week or 2 ago may or may not have been a factor leading to your pump shi*in itself???

[2rismo]

Hey cambell...Do you think possibly your MASSIVE burnout on the video you posted a week or 2 ago may or may not have been a factor leading to your pump shi*in itself???

That's just silly.

[FSTR32]

That's just silly.

It wouldn't surprise me. BTW ur silly

[Morgs]

One of my motors killed a N1 oil pump (new)

Though it was more the fault of a faulty balancer than the oil pump

[d0p3y]

Video killed the Radio Star.

QFT.

HTH.

[infected flow]

The above two statements are so filled with rubbish its not funny.

I would urge people to totally disregard both of them.

There are countless circuit GTR's down here running over 370rwkw, ALL use N1 Oil pumps.

Some into the 400rwkw region, still not an issue to date (over 2 years)

If the Vic GTR's can do it, its quite safe to assume that ALL others should be the same.

It cant be helped if your doing limiter launches and massive RPM burnouts all the time... which, isnt circuit racing at all, and isnt street driving either.

benigno - you will be fine with the N1 oil pump. Its people who are doing constant burnouts, massive amounts of high RPM launches etc that have the issues

As giant has stated, there is another thread on this which goes into much more detail than someone with little expirience.

okay this is a discussion right so u should really think about what your saying i have my opionon and you have yours if u dont like it fine i really dont give a toss...no i dont do burn outs and im no hoon so unless u have met me u should shut the f**k up ! f**kin keyboard warrior.

and anthoer thing maybe u should have some proof before u say this is rubbish not just state what u have been told or read!

cheers.

how can people talk about there experiences if u have idoit moderators like yourself telling people off...mmm

great forum...

[d0p3y]

okay this is a discussion right so u should really think about what your saying i have my opionon and you have yours if u dont like it fine i really dont give a toss...no i dont do burn outs and im no hoon so unless u have met me u should shut the f**k up ! f**kin keyboard warrior.

and anthoer thing maybe u should have some proof before u say this is rubbish not just state what u have been told or read!

cheers.

how can people talk about there experiences if u have idoit moderators like yourself telling people off...mmm

great forum...

Don't worry Mario it's well known R31Nismoid is a completely clueless tosser who just enjoys getting on his high horse. Karma will take its course one day. Don't stop posting your experiences/accounts on his accord, despite what he likes to think his opinion isn't the be all and end all to life.

[N I B]

Be good to see how many failed on early 26 or 20-25-30 short oil pump drive cranks,I've never had one fail on long drive cranks.

[GTRsean]

NIB, I was going to mention that as well, as the crank snout length to drive the pump affects the durability of the shabangas well.

R33 GTR cranks and onwards have a thicker drive so nissan must of picked it up a little late for the 32's.

I think I have a short crank drive being a 92 model and positive it has stock pump.

One of the first things I'd do when rebuild comes is fit a JUN collar before fitting an N1 just so it has enough surface area to drive the inner gear to hopefully avoid the problem.

[giant]

Be good to see how many failed on early 26 or 20-25-30 short oil pump drive cranks,I've never had one fail on long drive cranks.

just so you know, my engine was a brand new r33 n1 engine which failed the oil pump gear twice, which i believe was very much related to the type of activity we use the car for.

cheers russ

[Fitzpatrick Speed Works]

I have had 2 r33 N1 pumps fail and both are street cars, one cracked the gear after only 300km and on run in!!! The other cracked after about 10,000 kms both were brnad new pumps and both were rb30's.... Can anyone here do metalurgy tests to test if the gear drive material is the same as standard pumps as I believe they are a harder steel but a more brittle one thus prone to cracking....

In any case these dont seem like isolated incidences.

[Scooby]

has anyone tackled nissan on this? oil pump failure on run in is extreme.