Gpz oiling system vs kz, oil cooler vs non.

swest wrote: It will soon be time to install a thermo valve for cooler weather.
Steve

You first.

Here's some pictures of the GPz fitting.
I looked this thing a dozen times and didn't see that passage until tonight.
Looks to be abour an 1/8" hole

I'm not sure if the '83 fitting has any cooler by-pass feature, both of my examples are mounted on engines right now, so I can't quickly check. I had another one that I used to measure for a much larger cooler line take off, and I don't recall it having the by-pass, but maybe I'm thinking that because this version routes all the oil thru the coolers (there are two coolers and direct oil lines to the head on this one):

This one I machined for jberger635's big block GPz1394 cc fuel injected (micro-squirt) oil cooled (mostly) engine....it directs 67 % to the crank case and 33% to the head. Fittings are AN dash 10 out and dash 8 back into the crank case....no by pass, but there is room for a pressure sensor on top...

Another thing that comes to mind - it would be nice to have a pressure interlock switch on the oil lines to kill the ignition unless oil pressure at the main gallery is above 2-3 psi, 7-8 psi at the cylinder head (plain bearings in there)....

I never would have suspected that bypass hole in the gpz sending-unit fixture. Nice find.

Kray-Z wrote: Another thing that comes to mind - it would be nice to have a pressure interlock switch on the oil lines to kill the ignition unless oil pressure at the main gallery is above 2-3 psi, 7-8 psi at the cylinder head (plain bearings in there)....

That wouldn't be too hard to setup, possibly using the neutral switch to bypass the lockout during initial start (when there'd be no pressure). Or a time-based bypass that starts the clock ticking when the starter button is pressed (giving like 10 or 20 seconds to start building pressure before it kills).

I'm curious though, how does the pressure get to be higher in the head than in the main gallery? It looks like the main gallery feeds the head passages. Wouldn't the main gallery also have to be at the higher head-passage pressure in order to push oil upward?

I'll go back and look at the diagram again.

I think you're right. I believe it's a total loss system and any restriction would cause oil starvation in the top end. The Z1 has a tiny hole in the oil pressure switch gate (for lack of a better word) but I don't think it would be large enough to keep oil moving in case it got stuck. Maybe it's so it can drain back down slowly.
Steve

Back in the early days of the Z1, there was a service bulletin about how to rework the oil pump if the bike had a flickering oil light under hard acceleration. They told you to plastigauge the clearance between the pump body, and the gears. If it was over the limit that was given in the service bulletin, you then surfaced the pump bodies on a piece of fine grit sandpaper to you got the correct clearance. Kawasaki also offered a thinner pump gasket back then too. I don't remember the part number anymore.

I don't have a copy of that service bulletin anymore. If anybody has a chance to find a dealership that still has that service bulletin, PLEASE post on this site. It would be very helpful to many owners of Kz's.

In all my years of road racing my KZ1000, I NEVER had my oil light flicker or come on during acceleration after reworking my oil pump per that service bulletin!!!!

As far as running a temperature bypass valve, I just used to duct tape half on my oil cooler off on cool days. If the duct tape started to melt to the cooler fins, I would just remove the tape. If the tape did not start to melt, I just left it on the cooler. Worked fine for me all those years.

loudhvx wrote: I
I'm curious though, how does the pressure get to be higher in the head than in the main gallery? It looks like the main gallery feeds the head passages. Wouldn't the main gallery also have to be at the higher head-passage pressure in order to push oil upward?

I'll go back and look at the diagram again.

Jberger635's oiling system has the two feeds, main oil gallery and cylinder head, which are divided external of the engine, just after the second oil cooler. Oil coolers are in series, then lines split to head and main galleries. Pressure is caused by flow restriction. Pumps (positive displacement) only create flow. More flow and more restriction to flow increase pressure. Near the outlet of a roller bearing oil feed there is a significant drop in pressure. This is not a hydrostatic situation - there will be pressure variances within these dynamic systems. The engine won't light until the 7-8 psi is reached in the head. The 2-3 psi limit at the crank shaft bearing feed is precautionary (safety) for something going wrong in there....to quickly kill the engine before any added damage occurs (hopefully).

Pressure is caused by flow restriction. Pumps (positive displacement) only create flow. More flow and more restriction to flow increase pressure.

Just to make this a little easier to understand, I used to work in irrigation, farms , large sporting fields , and school fields, stuff like that. From the irrigation pump we almost always used 4 inch pipe to get the water where we needed it, reduction valves were then used to allow the use of 2 inch and then 1 inch pipe out to the sprinkler heads, each time a restriction in pipe size is introduced the water pressure rises, if we ran the 4 inch pipe to the sprinklers, the water would just trickle out, so the reduced pipe sizes are used to build pressure. This is the exact same principle used inside your engine, the galleries going to the head are smaller which builds pressure in the oil feed, allowing the oil to be pumped with increased pressure to the head...

Any time there is a dynamic closed fluid system, the usual concepts of pressure no longer apply completely. With closed pipe moving fluid systems, the system is dependent on energy conservation. Forgive me if I miss a few things, as it has been years since my last work experiences in this field, but I scored a final grade of 99.5% (Highest Ever!!!, the only time I could claim that while at University, so forgive me for bragging just a bit!) in 3rd year engineering school fluid mechanics, so I must have known this stuff pretty good way back then....

Basically it works like this....the fluid (liquid oil here - gasses are another ball of wax completely) has a certain level of energy stored as a combination of pressure, velocity (speed), and heat. There is energy loss as the fluid travels through the system from friction. With a constant flow, and therefore constant velocity in a constant pipe size, the only way the fluid flow accommodates this energy loss is with a slight drop in pressure and usually negligible decrease in heat. So if a long pipe is used to convey the fluid at the same flow rate as a short pipe, the fluid at the end of the long pipe will have less pressure due to higher energy loss. The pressure gradient through either pipe will show a higher pressure at the beginning (pump end) and gradually drop to the outlet end.

Kray-Z wrote: Any time there is a dynamic closed fluid system, the usual concepts of pressure no longer apply completely. With closed pipe moving fluid systems, the system is dependent on energy conservation. Forgive me if I miss a few things, as it has been years since my last work experiences in this field, but I scored a final grade of 99.5% (Highest Ever!!!, the only time I could claim that while at University, so forgive me for bragging just a bit!) in 3rd year engineering school fluid mechanics, so I must have known this stuff pretty good way back then....

Basically it works like this....the fluid (liquid oil here - gasses are another ball of wax completely) has a certain level of energy stored as a combination of pressure, velocity (speed), and heat. There is energy loss as the fluid travels through the system from friction. With a constant flow, and therefore constant velocity in a constant pipe size, the only way the fluid flow accommodates this energy loss is with a slight drop in pressure and usually negligible decrease in heat. So if a long pipe is used to convey the fluid at the same flow rate as a short pipe, the fluid at the end of the long pipe will have less pressure due to higher energy loss. The pressure gradient through either pipe will show a higher pressure at the beginning (pump end) and gradually drop to the outlet end.

That is correct, the way to increase that pressure loss, is through reduction by using a smaller pipe at the end to create a restriction, or smaller galleries in the case of our bikes, which then builds pressure , ...