TOPIC:

No there isn't a large o-ring between the cases, but there is a large 91mm o-ring above the oil filter area of the oil pan that is compressed against the case when you tighten the oil pan bolts. That shouldn't be the issue unless the oil pan was disturbed. The o-ring on the filter cover is 105mm. If it is properly installed and the components are in good condition and correct, I don't see how the o-ring could simply blow out.

Rick H.

Rick H., that is what got me in the first place. Just now ordering a new filter and something caught my eye. The photo of the filter I just bought shows one with more holes in the shell, larger and more densely spaced than the one I have pictured earlier in the thread. I wonder if I have the wrong filter. TBH, I really don't remember when or where I got that filter. This has been a very long term project,as mentioned earlier. All I remember is being quite surprised when, just before I first started the engine, checking and finding that brand new filter in place.

I am not familiar with the bigger KZ engines but bear with me. Anyone check the oil pressure relief valve? Or do these engines not have one. I haven't read where it was mentioned.

Yes there is a relief valve as such, but even if that was defective I don't think there is enough pressure build up to force the o-ring out of its location between the filter cover and the oil pan. If there is enough pressure to do that I would be super surprised. If the components for the oil filter cover, bolt and o-ring are correct and properly in place it should make for an almost seamless joint. I am not at home while this thread has been running, but I wish I were. I would like to see if there is any gap whatsoever between the filter cover and oil pan on my KZ-1000 just to verify what I believe is correct. Moreover, excessive pressure will/should take the path of least resistance. I am not so sure that path would be through the oil filter cover o-ring.
Rick H.

There's no gap. The pressure can build up enough to break the filter cover.
Steve

Wow, I am grossly uneducated on this engine. I was under the impression that this engine had a relatively low pressure, high volume oil pump. If it can generate enough pressure to crack an oil filter cover that is some seriously high pressure taking place. Just off the top of my head I would think that that type of pressure would find an easier escape path than through the oil filter plate. After having my filter cover and oil pan off it appeared to me that torqueing down the oil filter cover compresses the o-ring in essence filling the o-ring grove and sealing the junction between the two parts almost making them one. Quite amazing and just shows my limited experience with this engine.
Rick H.

KZ Zone from APE makes a trick oil filter cover and it comes with a new bolt.
All billet


LOW PROFILE OIL FILTER COVER

The original oil filter cover for lowered KZ race bikes. Provides the maximum clearance under the bike. OFC1000K kit comes complete with plate, special filter bolt, low profile drain plug, and allen wrench. OFC1000GPZComes with o-ring, plate, bolt and hex wrench.
The 2" minimum ground clearance rule is being strictly enforced by all of the drag racing organizations. Don't get caught too low.

OFC1000K Z1900 / KZ1000 thru '80 $57.15 (order this part online!)
OFC1100GPZ 1000J and 1100GPZ models $57.15
DPK900 Drain plug only for OFC1000K $19.95

Dave

Rick H. wrote: Wow, I am grossly uneducated on this engine. I was under the impression that this engine had a relatively low pressure, high volume oil pump. If it can generate enough pressure to crack an oil filter cover that is some seriously high pressure taking place. Just off the top of my head I would think that that type of pressure would find an easier escape path than through the oil filter plate. After having my filter cover and oil pan off it appeared to me that torqueing down the oil filter cover compresses the o-ring in essence filling the o-ring grove and sealing the junction between the two parts almost making them one. Quite amazing and just shows my limited experience with this engine.
Rick H.

You are correct that the oil feed is high volume - Low pressure but if there is a restriction or blockage pressure will build up.
Just like putting your thumb over the end of a hose pipe.
You get high pressure but low volume.

zed1015 wrote:

Rick H. wrote: Wow, I am grossly uneducated on this engine. I was under the impression that this engine had a relatively low pressure, high volume oil pump. If it can generate enough pressure to crack an oil filter cover that is some seriously high pressure taking place. Just off the top of my head I would think that that type of pressure would find an easier escape path than through the oil filter plate. After having my filter cover and oil pan off it appeared to me that torqueing down the oil filter cover compresses the o-ring in essence filling the o-ring grove and sealing the junction between the two parts almost making them one. Quite amazing and just shows my limited experience with this engine.
Rick H.

You are correct that the oil feed is high volume - Low pressure but if there is a restriction or blockage pressure will build up.
Just like putting your thumb over the end of a hose pipe.
You get high pressure but low volume.

I understand the concept on the garden hose theory, but if your water pump only has 40 PSI of pressure that's where it will stop with the hose blocked by your thumb. It doesn't keep increasing beyond that level. From what I read the 900/1000 engine operates at a much lower oil pressure which in my mind shouldn't build up enough force to push an o-ring out of position on a properly installed oil filter cover, or literally break said cover. I guess my thought process must be wrong on this.
Rick H.

Rick H. wrote:

zed1015 wrote:

Rick H. wrote: Wow, I am grossly uneducated on this engine. I was under the impression that this engine had a relatively low pressure, high volume oil pump. If it can generate enough pressure to crack an oil filter cover that is some seriously high pressure taking place. Just off the top of my head I would think that that type of pressure would find an easier escape path than through the oil filter plate. After having my filter cover and oil pan off it appeared to me that torqueing down the oil filter cover compresses the o-ring in essence filling the o-ring grove and sealing the junction between the two parts almost making them one. Quite amazing and just shows my limited experience with this engine.
Rick H.

You are correct that the oil feed is high volume - Low pressure but if there is a restriction or blockage pressure will build up.
Just like putting your thumb over the end of a hose pipe.
You get high pressure but low volume.

I understand the concept on the garden hose theory, but if your water pump only has 40 PSI of pressure that's where it will stop with the hose blocked by your thumb. It doesn't keep increasing beyond that level. From what I read the 900/1000 engine operates at a much lower oil pressure which in my mind shouldn't build up enough force to push an o-ring out of position on a properly installed oil filter cover, or literally break said cover. I guess my thought process must be wrong on this.
Rick H.

A little info regarding thee hose on a house versus a KZ oil system
Public water systems are usually a gravity system using water towers to create water pressure to your home . They can use booster pumps which are centrifical pumps, NOT positive displacement pumps . Your house pressure is about 45 psi , but it is not being forced by a geared pump like your bike . It can be shut off without busting your pipes as the pressure remains at 45psi.
On your bike every time your motor spins , so does the positive displacement pump which is always forcing oil into the pressurized system . So the 3psi which is what a Kaw 1000 runs at once warmed up ( Over 15 psi cold ) keeps forcing oil into the oil galleries and unless allowed to completes its journey to the sump ( where it is allowed to return to atmospheric pressure .
If oil flow is blocked and not allowed to return to the sump the pressure will continue to build until something gives out. Theoretically the motor could stall due to excess pressure not allowing the geared pump to increase the oil pressure any higher , but in the real world a o ring will fail first or a line will burst
Hope this is clearer than mud
Dave

Sounds like there is general agreement that there is a blockage somewhere. Knowing this I would probably disconnect the oil cooler and re-install the factory bypass setup to see if the system works correctly without it. If not, then the blockage is in the engine somewhere.

OP's post #815143 shows a filter bolt with an O-ring on the face of the shoulder where it would meet the filter cover. The only filter bolt we have loose at the moment is a '72 Z1 bolt that has the O-ring in a groove on the body of the bolt, where it would seal inside the bore of the filter cover. Not sure what motor OP is working with or if mama Kaw made a change in O-ring placement on later filter bolts that we don't remember. We measured the '72 Z1 filter bolt as 114mm from shoulder face to tip.

seanbarney41 wrote: ...The photo of the filter I just bought shows one with more holes in the shell, larger and more densely spaced than the one I have pictured earlier in the thread...

This is a NOS OEM filter.



The inner sleeve shows the same high density of perforations as the outer sleeve we see here. We've never taken the time to calculate the area of perforations vs total surface area but, Mama Kaw clearly wants to flow as much volume through the filter with as little pressure drop across the filter as possible. We've seen & discarded, unused, many afternarket filters that clearly did not have enough perforation density to accomplish either. The filter shown in OP's post 815143 seems to have sufficient flow area to allow for sufficient flow.

Our question is; why does the pressure bypass valve in the filter cavity not open if filter cavity pressure becomes so excessive? We'd do a rough test of it's operation by removing the filter and probing the relief bypass hole in the filter cavity with a small, soft probe such as a brass rod, to make sure the check ball moves.

Good Ridin'
slmjim & Z1BEBE