Engine oil surge issue

The early Z's had an issue where they would lose oil pressure under hard acceleration. As you all know to get around this most fitted a gate valve in the sump to prevent oil from running to the back of the sump causing the oil pump to surge (my Z1R had one fitted early in its life)

My question is, does the air cooled GPZ1100B2 engine suffer the same problem?, because I noticed the top end rattles after a drag and normally it sounds perfect. The GPZ has an oil level switch but it does not have an oil pressure switch, so I have no way of telling if the pressure drops. Do I need to fit a gate to the GPZ sump?

only the very early Z1 had this issue they had NO dam between front and back of pan they field fixed the early Z1 with a pan with a dam cast into them all later Z1 had this along with all 1000's and including GPZ1100's

All the big Zeds including the GPZ's require an oil pan gate to prevent oil surge when use hard or drag raced so the answer is YES! you need to fit a gate to the GPZ.

Mine use to do that. Weak oil pump. This time I went through it and it doesn't happen. There is lots of oil in the sump so it shouldn't be a problem. I'll put in a gate eventually but it hasn't been an issue.
Steve

Yes the 1st pan had nothing! Wonder home many Dealers had warranty work with blown engines? :woohoo:
I just happened to sell this one this summer on ebay.
It went to Japan? Maybe a true restoration? Guy must have been anal? Unless the ribs were different on bottom?
It sold for $30 bucks. Inside cast mark had # 1

My 78 LTD had the cast in oil Baffle.. Not really a dam. It slowed oil flow to the rear of pan

A Hinged Gate was the ticket to cure oil starvation under rapid acceleration Like ZED said ..

Dave

Thankyou all, there seems to be a mix of opinions, I had a spare GPZ1100 engine casing and checked it out last night. The zig zag on the pan is similar to my Z1R. At higher revs (around 9/10K on the Z1R) my oil light used to come on, so a great west Australian drag racer (Ray Easton) told me to add a gate which fixed this problem.
BUT I thought Kawasaki would had this issue fixed when the GPZ engine came out but when I started to rev my fairly new engine out (to around 9K) on my GPZ1100, I got a loose shim sound on the top end which I believe is due lack of oil. After a some seconds the sound would disappear, Since I don't have an oil pressure sensor it took a while to work out why I got the topend noise.
I'm convinced I need a gate especially when using the A3 cams and a well ported head.
FYI, I did change the oil pump for a new one I had and the problem still occurred.

DFIGPZ wrote: only the very early Z1 had this issue they had NO dam between front and back of pan they field fixed the early Z1 with a pan with a dam cast into them all later Z1 had this along with all 1000's and including GPZ1100's

I have to admit I didn't know the early Z'd oil pans had no Zig Zag at all, as Z1Kzonly pointed out, they must've had some issues with the early engines under drag conditions.

The oil pans cast in baffle is ok for general road use and Kawasaki never changed the design for the GPZ's.
As soon as you start subjecting the bike to regular bouts of hard acceleration or racing the cast baffle just isn't enough and you need to fit a gate at the very least or better still a rear pick up.
As for the early bikes pump problems, this was an air lock issue which could happen at any rpm under normal riding conditions and was not related to acceleration induced oil surge and pump starvation.
Also the rumours that the later oil pumps were of a higher capacity is a myth and in fact move exactly the same oil volume at the same pressure as all the other Z9/Z1000 pumps and the only possible advantage of fitting a newer one is that it may have less wear.

If you are using the bike hard - FIT A GATE..

zed1015 wrote: The oil pans cast in baffle is ok for general road use and Kawasaki never changed the design for the GPZ's.
As soon as you start subjecting the bike to regular bouts of hard acceleration or racing the cast baffle just isn't enough and you need to fit a gate at the very least or better still a rear pick up.
As for the early bikes pump problems, this was an air lock issue which could happen at any rpm under normal riding conditions and was not related to acceleration induced oil surge and pump starvation.
Also the rumours that the later oil pumps were of a higher capacity is a myth and in fact move exactly the same oil volume at the same pressure as all the other Z9/Z1000 pumps and the only possible advantage of fitting a newer one is that it may have less wear.

If you are using the bike hard - FIT A GATE..

Totally agree, especially about the oil pumps, I could not find ANY difference between the Z900 to GPZ (apart from the GPZ having the pressure release valve on the oil pump housing vs Z900 on the main engine housing).

I am definitely in the drag category, so a gate it is.

I used to rag the nuts off mine :laugh: with standard sump and didn't notice any problems.

I'm going to be controversial here and suggest -under "normal" riding it shouldn't be a problem on a later bike.

Personally I'd rather see a 1/4 a mile wheelie on a 900/1000/1100 than a 550 or 750, just because ( I think)roller bearing cranks like a two stroke can tolerate temporary oil startvation wheras a plain/shell bearing crank that relies on oil pressure to make the bearings 'float' really can't.

Early 550 had an oil pressure warning, later was an oil level warning. I only got a low oil pressure light a couple of times when it overheated when stuck in traffic and really hot weather. I stripped the motor 10-15k later and all bearings looked good and within spec...on a 50 k motor.

Tyrell Corp wrote: I used to rag the nuts off mine :laugh: with standard sump and didn't notice any problems.

I'm going to be controversial here and suggest -under "normal" riding it shouldn't be a problem on a later bike.

Personally I'd rather see a 1/4 a mile wheelie on a 900/1000/1100 than a 550 or 750, just because ( I think)roller bearing cranks like a two stroke can tolerate temporary oil startvation wheras a plain/shell bearing crank that relies on oil pressure to make the bearings 'float' really can't.

Early 550 had an oil pressure warning, later was an oil level warning. I only got a low oil pressure light a couple of times when it overheated when stuck in traffic and really hot weather. I stripped the motor 10-15k later and all bearings looked good and within spec...on a 50 k motor.

Tyrell, I agree about the bearings and the cam insert bearings, they can take a lot without much oil, which is why I'm not panicking about a blown or damaged motor.
I also agree that a standard Z can run without any mods but if you add some cams and other mods the mid range and topend power surge will tip the engine over the edge (when the oil is very hot), my engines are limited to 9,500rpm but will run to 10,000rpm under load before power drops, which is above standard (I used to change at 8,000 to 8,500rpm on my standard Z1R before power drop).
Also here in W Australia we can get over 38 degrees C most of the time during summer so the oil is like water, even with an oil cooler (nothing fancy) I get up to 85 degrees C at the engine, that's most likely when I'll get the oil starvation issue.