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650ed wrote: Makes sense to me. I wonder if the turbo 750 pushed things a bit beyond the design level of the oil pumps used in the 650 and normally aspirated 750 engines. For example - the KZ650-C1 made 64 hp while the 750 turbo GPZ makes 112 hp (see 1st link below). With that much oooomph that turbo 750 is probably putting a lot more stress on the internals. Some heavily modified turbo 750s put out as much as 282 hp! (see 2nd link below) I wonder what they use for pumping oil through those beasts; I can't believe they use the stock pump, so maybe there's a unit that could be easily used in the street turbo bikes if the stock units aren't up to the task. Ed

www.motorcyclespecs.co.za/model/kawasaki...pz750_turbo%2083.htm

www.750turbo.com/forum/viewtopic.php?f=9...cfe43309e10ecd320fd3

Makes perfect sense and I would tend to agree with ya there too, Lorcan as well as many others there are producing some mind boggling power numbers out of a relatively small inline four air cooled motor. You are also right that they upgrade the oil pump and in this case it's the same ZR7 oil pump we are talking about here too.

Brett

interestingly, it was me who revealed to lorcan about the bigger ZR-7 pump, look in the racer build thread link he thanked me, big honour!

BTW, you can do the pump swap with motor in place, the three bolts that hold the pump are behind the the clutch basket and the pump drops down from bellow.

It's interesting that Kawasaki uprated the pump on the ZR7, which isn't a hot rod engine. Apparently they felt that this was a reliability improvement or they wouldn't have done it. I've seen a number of KZ750's where the head gasket was weeping oil at the galley passage up to the head. Adding more flow wouldn't help that situation any. Does anyone know if Kawasaki did anything to improve this tendency on the ZR7 engine?

That is awesome. I've considered it since the GPz motors are hard to find. It'd be cool just to swap one in so you don't have to worry about flogging the original to death. It looks like the engine mounts are still the same and everything. I'm definitely going to look into the oil pump upgrade at the least.

turboguzzi wrote: interestingly, it was me who revealed to lorcan about the bigger ZR-7 pump, look in the racer build thread link he thanked me, big honour!.

Genious!
"Sos groso, sabelo!"

turboguzzi wrote: interestingly, it was me who revealed to lorcan about the bigger ZR-7 pump, look in the racer build thread link he thanked me, big honour!

BTW, you can do the pump swap with motor in place, the three bolts that hold the pump are behind the the clutch basket and the pump drops down from bellow.

Very very cool, I love hearing the back stories about stuff like this thanks for sharing and big kudos!!

Brett

Nice. I definitely see more Kz750's than Zr750's. I wasn't aware the Zr had a primary chain tensioner. That'd be nice on cold starts.

The only diff.s that I know of between the n/a and turbo motor's is the turbo motor has a scavenge pump
to pull oil out of the turbo, 1 mm larger wrist pin's, lower C/R piston's, KZ650 cams and the head is drilled and tapped
for a temp sender.
The deal with the ZR7 oil pump in the turbo motor is more volume to help cool the
bearing's in the turbo from what I've read.

I have also read of the benefits of having additional flow from the zr-7 oil pump, so I have acquired one for my kz750e rebuild.
But one thing still confuses me and that is in the FSM for the zr-7 it shows ( in two different areas) that the oil pressure should be 14.5psi @ 3000rpm. Which is vastly lower than the kz750e FSM listed 28-36psi @ 4000rpm. I know there is a 1000rpm difference but I can't belive the oil pressure doubles in 1000rpm. (Plus I have also checked my oil pressure on my zr550 in the past and it also shares the same oil pump as all the other kz650/750's and it showed 20-25psi @ 1500rpm's)





Does the zr-7 have HUGE oil galleys that provide a large flow of oil but at a lower pressure than that of the other KZ's?? If so, I am worried about over pressurizing the oil system and creating leaks or causing bearing damage from to much flow past the bearing surface.
I am also aware that the zr-7 uses a different design of oil pressure relief valve, but the FSM does not specify what pressure it releases at. The KZ750e relief valve releases at 63-85psi. So could the zr-7 relief valve is designed to blow off at much lower pressure??

Do the 650 and 750/4 engines have oiling system related failure issues? I've heard about 550's spinning crank/rod bearings but not the bigger engines. Assuming no, then I'm not sure what good using a bigger oil pump will provide. The pressure relief valve will just be passing more oil than before and there may be more risk of oil leaks.

One possible benefit is for bikes with an add on oil cooler. That same pump was used for 17 years, including on bikes with oil coolers, so I'm not so sure there is an issue regardless.

I will be using a zr-7 oil cooler on my motor, so the extra flow/pressure from the zr-7 pump was part of my reasoning. I will be using the zr-7 pressure relief valve just for the sake of continuity. Kawasaki saw fit to completely redesign the oil pump it had been using for 25 years just (and only) for the zr-7, so I thought they may know something we don't.
I also read of the #3 rod bearings burning up on the 550's, and the one time I bought a "running" gpz550 engine off of the internet, it showed up with the #3 rod bearing welded to the crankshaft. Last time I do that.

Here are the part numbers For the pump and the relief valve . On the turbos we also drill out the passages on the pan . The turbo needs oil .
ZR7S Oil Pump PN 16082-1158
ZR7S Relief Valve PN 16130-1058

This is the thread that explains it all . There's a lot of talented guys on that site . I'm not one of them but learning .

www.750turbo.com/forum/viewtopic.php?f=10&t=13810