Why Do Oil Pumps Fail?

[No.96]

G'Day,

Background

I'm building up a budget gtr track car (if such a thing exists), I took it out once and did number 6 big end bearing.

I am now rebuliding it and have done all the standard fixes oil restrictor, head drain, extended sump and oil cooler. I will keep the revs down to 7800ish and just change gears to go faster (ha ha).

I am thinking of reusing my 115k oil pump (shock horror), I measured it up and the clearances seem ok.

My Question

I have read a bit on this topic and what I can work out is it seems all crank driven oil pumps (even Jun) fail due to crank vibrations/harmonics through either high revs or rev limited induced harmonics. What do you think?

If this is the case as long as I keep the revs down and don't sit on the rev limiter the standard pump (N1 pump with weaker relief spring) should be ok?

Am I mad or does this sound OK

[mico]

the weakest link in a gtr is the oil pump. i would be replacing it with a good one that has forged gears 4 sure.

[Duncan]

I think your plan sounds sensible. I have never broken an n1 oil pump. Just keep it off the limiter, have a crank collar and don't do repeated launches without loading up the driveline first.

If you look at the actual number of people who have had problems and how they used the cars you will see they don't fail half as often as the internet would have you beleive. And when they do fail they have generally lived a hard life first.

I sure wouldn't resuse a 100000klm old one in a race car when a new one is $400 though.

And do remove the backing screws in the pump and loctite them again before using it. They do sometimes come loose.

[R.3.2.G.T.R]

how bout having a a/m harmonic balancer for added insurance?

[joeleo87]

Recently ive spent a fair bit of money on my GTR and the last thing i want is to spin the bearing :S

ive never taken it to the track and i never rev it past the limiter.

How do i know when my pump is on its way out? when should i change it?

[R31Nismoid]

Smash the limiter, you'll break pumps... simple as that. That's what kills the pumps. Its not harmonics or anything else.

Plenty of track cars here using N1 pumps, over 350rwkw, no issues.

Don't smash the limiter, you wont have a problem