DJZ's 280ZX

[DJZ]

Can't quite put my finger on it but I think somethings not right here.

[broke]

OUCH!

That really sucks man, I hope nothing else in the motor got damaged when this happened. Those Nitto oil pumps are supposed to be pretty good if you're looking for a replacement.

[DJZ]

If you really want to beat on this motor, you should seriously consider a nitto oil pump for it. The oil pump/oil pump drive is the weakest part of an RB. Steer clear of the N1 pumps, I've read all sorts of horror stories about them.

There's one thing I should have done when building the motor and it was listen to Bart!

[Datto_610]

Nooooo! Sucks big time but FJ ftw!

[nick_m]

boss gets a company in oz to make him some new gears to fit in the n1 housings, as mentioned the n1 gears are ham. That way he gets good gears and the bigger volume of the n1 pump

[DJZ]

What's a new gear set worth? That would have been my best option if the broken
gears hadn't damaged the housing.

[Bartman]

It does suck dick that a Nitto pump costs as much as building the rest of the engine. But if it only means building the the engine once, it makes economical sense pretty quickly.
As said at dinner last night,
at least it was you who broke it, not someone else.

[DJZ]

Yeah, I'm leaning towards a Tomei pump at the moment, depending on what else has gone wrong. I've asked one of the NZ distributors for a price on the Nitto pump, they are $1375AUD on eBay.

There's one other thing that may have caused this or has been a contributing factor which I haven't mentioned yet. I undid the crank pulley bolt with a ratchet, now when the torque spec in the manual calls for 446 - 466Nm this made me worry. Now it's either come loose because of the oil pump failure (which I doubt) or it's been tightened incorrectly which has caused the balancer to wobble and wear either the crank snout or the balancer itself as there is a fair amount of play between the two now. This probably means that I'm going to need to replace the balancer and possibly remove the crank and see about getting the snout repaired so I'm pretty close to just building an RB30 bottom end. I wasn't the last person to do up the bolt and I should have rechecked it myself.

[85_Z31]

Can you run the dial gauge over the crank snout while it's still fitted in the block ? it might be ok

if you check the OD's with a Micrometer and compare to the service limits you might not need to do anything with the crank at all, if it was only a balancer that needs replaced you might still be in business ?

[DJZ]

Pulled the motor out today and took the girdle off, there is some damage to the bearings but overall it's not actually that bad. I'll whip the crank out, get it polished (or ground if need be) and get an opinion on the snout and crank collar but I think I'll get it machined off and another fitted. Slop between the collar and the oil pump is bad.









The Tomei pump that I want to get (and should have got in the first place) is unique among the RB oil pumps, the gear set is actually 3 piece rather than 2 like all the other pumps, having the splined centre gear is suppose to help take up any slack between the collar and the pump gears. Apparently Nitto is or has been working on what I think would be a direct drive splined pump where the crank collar would be splined I guess? Apparently that's the way JZ motors are.

Not really sure what to do right now, there's no point putting the motor back in without replacing the clutch but I can't afford the oil pump + a new balancer and a clutch at the same time. I've got the red top RB20 sitting there which would drop straight in but I'd need to get it tuned. Might just have to put the car aside for a while till I can afford to do everything at once.