RB26 V's RB30 - block strength?

[PLAYA]

Apparently harmonics can also hurt the pumps thats why lots of people are going to the big ATI style balancers that are supposed to help. Iv got one ill see how it ends up going.

[JZK25]

What part of the pump fails? Does the gear split or something?
Anyone got pics of a busted pump?

[PLAYA]

yea 2 seconds, pump actual splits





that was was pretty hammered

for comparison this is a N1 pump after 20K freshen up



This was posted by sydney kid, either love him or hate him, not sure what to think.

"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.

[stockymcstock]

you can see in those pics that the drive flat on the crank is not meeting up with the width of the flat on the pump. that would be why it has failed.

[RB30-POWER]

how do you even get that kind of wear on the metal?

maybe he should use royal purple that has molyb in it, extreme pressure additive in oil ftw!

i love the shit!

[PLAYA]

you can see in those pics that the drive flat on the crank is not meeting up with the width of the flat on the pump. that would be why it has failed.

That is the long pump drive....

[browny]

Maybe that wear occured after it cracked and what we can see is a result of the drive ring expanding and moving around?

[JZK25]

The crack looks like a product of the pump chattering against the drive due to a size mismatch(pretty much what stocky said).
I would have though the clearance between the two would be something you would carefully match in a race engine, especially if there is a known issue.

Edit - Good point Browny.

JZ engines use a spline drive for the oil pump. Just FYI.

[stockymcstock]

wonder how hard it would be to put two tiny half-moon keys into the crank/pump drive? wouldn't need to be very big. oppose them 180 degrees and robert's your mother's brother?

[PLAYA]

The problem is i don't think its the actual design on it, you never see the issues with SRs and the oil pump looks the same?

[PLAYA]

Well i know it is the design because if it was designed correctly there would be no issue, but you get what i mean.

[TJ]

PLAYA - got a link to the thread? Those pics are hosted on my good mates imageshack, wasnt aware he was talking about it on SAU.

[PLAYA]

PLAYA - got a link to the thread? Those pics are hosted on my good mates imageshack, wasnt aware he was talking about it on SAU.

nigga here it is

http://www.skylinesaustralia.com/for...hl=n1+oil+pump

[shanef]

Theres also this jun pump that failed in a rather interesting way too...

[RB30-POWER]

would be interested to know how much horsepower it takes to drive one of these oil pumps during normal use?

could provide some insight on how much energy is being pumped into them, especially at high rpm?