The Fabled N1 Oil Pump Debate

[Brockas]

Continued from this thread which was hijacked:

http://www.skylinesaustralia.com/forums/Po...20&start=20

For some reason, a few trusted people on here swear by the N1 oil pumps, claiming poor harmonic balancers are to blame, and incorrect assembly etc etc.

Here's a picture of my oil pump, taken off a Nissan-built R34 N1 motor, which had done ~22,000kms. Hardly old, and hardly what I'd call 'carelessly assembled'.

Yes, it has seen the track, but it hasn't copped limiter launches every second day of it's life. I would say this car has been treated in a typical 'GT-R' way, by which I mean it is being used for what it was designed to do.

Draw your own conclusions, but I haven't (and would never) gamble my $10,000+ motor on one of these lasting.

Luckily for me my motor was stripped down and rebuilt before this let go completely...

[Adriano]

Did it ever see the rev limiter? Or limiter launches?

[Swiper the Fox]

Did it ever see the rev limiter? Or limiter launches?

clearly...look at both the drive and trailing face of the pump...both very worn.

N1 pumps are not indestructable....no mechanical part is.

Edited May 15, 2008 by DiRTgarage

[The Dan]

It appears as though you did have one but was there a crank collar fitted?

[NYTSKY]

Whoa nice crack! What collar was fitted and what was your RPM limit set at?

[Bliksem]

He wouldnt need one, the problem was fixed by R33 onlwards

[NYTSKY]

Wouldnt need one?

[Bliksem]

Correct, crank collars only need to be fitted to cranks where the oil pump drive is too short. RB20, RB30, and early RB26...

In saying that though It looks like the crank drive is still a few mm short on those pics, but that is nothing by comparison to what a photo of a failed pump off an early pump looks like.

[johnbarry88]

I would think if you wanted it to last longer you would pull it apart and debur the gear on the inside edge. You can see all the sharp ridges in the picture they are multipul stress risers...

[R31Nismoid]

http://www.skylinesaustralia.com/forums/N1...il+pump+failure

There was a massive thread on it here also

Either way, as RPMGTR said in the other thread, he's seen all of the pumps munched, big $$$ or not.

So end of the say it comes back to the operator behind the wheel and their driving style

[N1GTR]

Great pic though, as others have said nothings indestructable - good thing you caught it early

[Swiper the Fox]

my question is...if a N1 engine only had 20 000klm on it...and it was looked after...why was it pulled down?

abuse perhaps?

[STATUS]

i still reckon look at the build and not take it for granted, int balance, ext balance components.. harmonics etc as i know of alot of 'abused' rb's running N1 pumps. That said i always use the greddy or tomei ones as nowadays they are not that dear.

[NYTSKY]

I guess if your gear is not balanced properly any pump will fail.After all its the vibration that kills them isnt it?

Should last the distance if everything is the way it should be and assembled right.

If mine fails ill be sure to let you know

[Swiper the Fox]

This is an N1 pump out of another 20K engine im currently doing a freshen up on...notice how the pump is only worn on 1 side of the drive face.

and this engine was a built one that regularly saw 8000rpm and produced over 350KW at the tyres

[Angus Smart]

I had a crank pulley problem on my car,

the pulley came loose, and the keyway got a bit shagged, i'd say there would have been some vibrations problems going thru my engine for a few 100km's

this was just before cylinder 6 copped a hole down the side, which would have been hard caused by leaning out as it has a very very fat tune.

it will be very interesting to see if i have any problems with my N1 pump when i pull it off. it has seen alot of abuse i guess photos will follow when i get around to it.

[Angus Smart]

Also.......... What is the difference between N1 and Nismo pumps??

[STR8E180]

this is the oil pump my tuner has machined up for his RB26 engines

they are CNC machined billet stainless which has also been heat treated

personally if i already had a N1 oil pump in my engine i wouldnt rip my engine apart to upgrade it but if i was already under going a engine rebuild i would upgrade it for some thing stronger

Edited May 16, 2008 by STR8E180

[Sydneykid]

clearly...look at both the drive and trailing face of the pump...both very worn.

I agree with Paul, the drive flanges are BADLY worn. Something is wrong, either the crank has worn drive flanges, which we see a lot of, or the engine (crank and pump) has done way more than 20,000 k's.

Let me throw another one in here from other engines running a crank driven oil pump. I have seen oil galleries blocked with machining swarf, as a result the oil pressure skyrocketed and the pump drive flanges cop a hiding from that. The crank bearings failed due to lack of oil from the blockage but the pump is blamed because it has cracked. Rebuild the engine, don't find/remove the swarf and the next ouil pump fails as well.

Cheers

Gary

[Brockas]

Great pic though, as others have said nothings indestructable - good thing you caught it early

Cheers, I'm not saying an N1 pump is definitely going to fail, more so making the point that they do, even on 'low km' engines. I have no reason to lie, it really doesn't bother me either way, but thought some of you might appreciate a picture

my question is...if a N1 engine only had 20 000klm on it...and it was looked after...why was it pulled down?

abuse perhaps?

Negative.

The decision was made to chase ~600hp at the wheels. Obviously an N1 engine isn't going to handle that with cast pistons/rods. Instead of grenading a perfectly good motor (and possibly damaging the block in the process) it was stripped down and rebuilt.

Originally I was going to retain the N1 pump, lucky I didn't.

Yes, the car saw a few limiter launches, but no more than any other GT-R I would suspect.

If the oil galleries are blocked with machining swarf, I'd expect to see worn bearings. My bearings had almost 0 wear. Bore was only 2-3 thou worn on each bore, and the head shop said it was the best RB26 head they've ever seen.