Water Pump Options

[Dale FZ1]

I've just experienced a water pump failure on a track day. Stock-type aftermarket RB30 pump, total running km about 2000. The bearings collapsed, skewing the rotating bits and the pump seized/spat water out. No issues with overheating prior to it failing, and the water picked up on rear tyres caused an off track excursion so problem identified quickly.

The question for all 30DET builders who use theirs for regular track work is - what spec pump did you use, and have there been any other similar failures?

I'm considering whether the RB30 pump is not suitable, even with a 7200rpm hard cut, and driver-imposed limit of 6500? Other than the price difference, an N1 can go in but if I've just copped a crap pump then will replace it with another stock type.

[TiTAN]

if its more track than street you could fork out for the N1, i just threw a standard genuine Nissan RB26 pump on mine. have not had any issues in 20,000km with it.

[Dale FZ1]

The failed pump sitting in front of me has an 8 bladed impeller.

A GMB branded (Made in Japan - reputedly good quality) pump Part # WP898 from Repco has a 6 bladed impeller but looks otherwise similar. The shape of the backing area is smoother, but not flush-fitting as the N1 design appears to be from pics I have seen.

Less blades should be more efficient at higher pump speeds, and maybe not quite as good at lower speeds, same principle as per turbocharger impellers.

Pics of the N1 looks like it is a better piece of kit altogether but I think its pointless spending the extra if the majority are running stock-type pumps without problems.

So what does a stock RB26 water pump's internals look like?

Edited February 21, 2011 by Dale FZ1

[Adriano]

Were tou running excessive belt tension

[Dale FZ1]

No, belt tension checked prior to the event and within spec.

[turboedsloth]

I have those wp898's at work and they have 8 blades, are a trueflow item

[Dale FZ1]

I think it might depend on what batch of impellers they had available. The one I saw had 6 blades. Genuine pump from Nissan spares had 8, same as the original pump on my RB25, and the failed aftermarket pump. The general finished quality of casting etc on the genuine gear looks higher too; that's what I went with, not going to have another event spoiled if it was a case of inferior quality.

Front of the engine is reassembled, waiting for spare time to install the radiator and add water this week.

[Frosty]

Nissan 20/25/26 are the same from memory and Nissan! My 26 had a 6 prop

I Would think it would bolt to a rb30 also??

N1 I'm not sure is worth the extra money IMO just run a good rad/fan setup and temps will be fine

[bubba]

Genuine OEM RB20 water pump.

The N1 water pumps are designed for engines regularly spending most of their life over 7000rpm.