The oil starvation on no.3 journal bearing has been around a long time.
All the motors that are derived from the GPZ900 have this issue upto the ZRX1200 and ZZR1200 - which were modified to avoid this.
I found this some time ago on BigBikeworld forum -
It is my opinion the main reason these engine die is oil starvation, the dreaded #3 rod bearing failure. For 15 years I used a ZX10 in a race car and although it was a dry sump system there were many modification made to give it both HP and reliability. My focus was improving the oil system, primarily increasing volume and pressure. Pressure was easy, just put a shim in the relief valve and/or use the racing relief valve. Volume was not so easy.
Below are pictures of a few of the mods made to improve volume. Over time I’ll add to this; I’m getting rid of all my ZX10/11 engine parts since I have been running a 04/05ZX10R for the last 4 years and as the stuff leaves my shop I keep finding things and I’ll take more pictures.
In another post my brother talked about a crankshaft mod and I will take pictures of the crank and post them as well.
The pump in a ZX10/ZX11 puts out a lot more oil than reaches the bearings, all the oil must pass through the filter bolt. The bolt on the right not only has the hole elongated but the inner diameter has been drilled and the cross sectional area is approximately 50% more, and the bolt has been shortened 1/8in because it blocks the passage if left full length. If you look carefully at the bolt on the left you will see some flashing in the hole from the drilling operation, of course the bolt must be carefully cleaned and deburred.
The oil pump is bolted onto an aluminum bracket which has cast holes; when holes are cast they have what is called draft so the hole at the outboard end is much larger than inside; I put the bracket in a drill press and drill these holes to the max size for their full length. Also there are many areas in the passages that can be rounded and opened up to improve flow and less restrictions.
The oil pump interface to the pump bracket is sealed with an o-ring with a “D” cross section. When this o-ring is installed and the bolts torqued the o-ring squishes into the passage thus reducing the passage cross section and disrupting the flow. I have taken an old pump and a bracket sawed them up and drilled holes allowing access to the installed o-rings, then I use an exacto knife to cut the o-ring back to the full diameter of the passage. The picture with o-ring clamped is a little blurred but the dia of the oil passage is 0.470in and with the o-ring it is just under 0.400in
The pump is also ported to improve volume output; the picture on the left shows 2 scribe marks in each chamber, on the left the area in red can be removed which increases volume output.
The next picture is the oil hole in the main bearing cap. On the left is the stock cap and the left one with the hole opened up. Following is the bearing in the cap, I use a dremel tool with a small ball cutter through an old bearing to remove the material blocking the passage. Under the bearing shell I use the same tool to open up the passage between the bearing holes.
The next picture is the case, unfortunately I have no pictures of the ported case. In the area noted the corners are rounded, fluid hates 90 deg sharp corners.
Between the pan and case is a tube which feeds the main cap and another oil gallery. We fabricate a new tube from 3/8 dia steel brake line which is a larger dia than the stock part.
Rod side clearance on stock rods is 0.009in (if I recall correctly) and Carrillo recommends 0.013in (again if I recall correctly). This increased side clearance is to increase flow for cooling, Even on stock rods I ran the Carrillo numbers.
At the bottom are pictures of the ZX10 in the car. Look closely at the right side picture and you can see a line from the right front corner of the head; this line is a gravity oil return to the dry sump tank. In long left hand turns at 2g’s even with a dry sump enough oil is pumped and will stay in head to run a 6 quart system dry. There is enough force to push the oil back to the tank, before installing this fix the dry sump system required 8 quarts of oil, an additional 4# to eat up HP not to mention the HP loss of the valve train fighting all the oil trapped in the head.
Again looking closely at the installed engine and you can see the wires are not stock. That is Moroso spiral carbon core wire in a Chrysler Hemi spark plug connector with a stock Kawi boot and the other end is attached to Accel coils. This was required to keep the ignition noise with stock wire from interfering with the data acquisition.
The next picture is a broken crank. This engine ran out of oil due to a line failure in the dry sump system. The driver failed to notice the BIG glowing red light. Data acquisition reveled this engine was at zero oil pressure at 12k for a very long time in several gears before finally calling it quits. Those are Carrillo rods.
The last picture is the ZX10R being installed that replaced the ZX10, and sadly I’m just finishing chassis modification to install a GSXR which will replace the ZX10R. My best ZX10R makes 185HP a similarly modified GSXR makes 200HP.
Someone has asked me about the number of engine failures I have experienced. Well certainly more that most bike riders since it was used highly modified in a race car. In my early days 3 for the #3 rod on my engines, and one #3 on a sponsored engine I ran; one broken stock rod just below the wrist pin at maybe 4k rpm on a cool off lap after the checkered flag, Carrillo said that was a very common failure and I personally never used a stock rod engine again; one dropped valve, this one was caused by worn valve keepers, after this one I began looking at the keepers under magnification and found many were worn and went in the trash.
I ran a lot of Mega Cycle cams and lost lots of rockers until I started using nitrated rockers that a friend made in his garage.
There was the odd things that would go wrong from time to time but were not catastrophic.
We are restricted to 1L engines, made up from any source more or less. I ran a 900 crank, ZX11 high compression pistons, a milled and ported ZX10 head with ZX11 valves, the cylinders had to be notched at the top to clear the valves. The head was the work of Craig Hansen in Chico CA and found the ZX10 head with ZX11 valves to be superior to the ZX11 head. Oh and the crank was lightened by 8#, you can see a picture of that in my parts for sale ad. I broke one transmission and that was when I was using an early version of a speed shifter. The clutch had and extra disk and was made up using the stock Kawasaki friction disks and the stock metal disks from a 1000rr. I’m using a similar extra disk clutch in my ZX10R using stock Kawasaki parts. BTW I never found a out of speck used friction disk from the old ZX10, but the new ZX10R friction disks have cost me an engine, they do not seem to hold up in the race car.
This model ZX10 is my favorite, easy to work on, but limited to about 160HP less than a stock new ZX10R, or R1 or GSXR so that is why I moved on.
David
Unfortunately, it wont let me copy the pictures across.
