Phil
The zx10r is like my prostrate. It doesn't have an oiling problem, It has a piston to cylinder blow by problem. The Dry sump is used to address the problem of "puking oil" whenever you keep them at high RPM for a long period of time. I used to vent the breather to my ex pipe to try and pull a vacuum on the crank case. Well after about 10 laps of racing the smoke would just start rolling out of the exhaust. At first it worked pretty good because the guys in back would back off to try to be able to dodge the up coming explosion. They finally figured out that wasn't going to happen,and all that smoke became embarrassing to Doug and myself. If they would throw a yellow flag for a couple of laps the smoke would go away and everything would be fine for the rest of the race.
Next we tried several dozen different breathers some worked better than the others but none were very successful. I can remember Mark coming over to Bloomington and saying he had found the secret, only to throw oil all over the place and drop out.
Zx10r's have been a challenge to me and many other racers. While doing the dry sump thing I also did some testing, to try to find out what my problem was. I installed an electronic vacuum sensor and noted the crank case vacuum in the old Kaw. I used an ultra high tec Roots type scavenger pump mostly found on NASCAR and INDY cars. Up to 10,000 RPM that thing would pull the crankcase down to 10 to 12 inches of mercury. At 11,000 the crank case was at 0 by 12,000 the crankcase was on the positive side and rising. By using the dry sump and larger oil tank (more weight) we could eliminate the blow by problem and keep my drivers feet dry.
The Gen 4 Kawasaki has supposedly addressed this problem by paying particular attention to boring the block by installing bore plates and offsetting the bore to the thrust side of the piston, (what Chevrolet did in their old 327 ci engines) many years ago. We will only be able to tell if it works by racing it.
When Kawasaki did all this improvement on their engine they also designed the engine to work better in a race bike. They stacked the engine on top of the transmission to raise it in the bike to improve handling. The oil pan on the Gen 4 is a good 12" tall. the oil pick up is in a deep well to the left of center, great for a race bike. They went so far as to put the oil filter in the pan itself separate from the crank case. They cast oil galleys into the oil pan and send the oil around and around until it finally gets to the crankshaft. Talk about a mess. They weren't thinking about being dominate in mini sprint racing just motorcycles. If we want to use them we are going to have to do some development work on them to make them work in our cars.
If the other makers decide to follow Kawasaki idea and stand their engines up Mini Sprint racers and several other classes racers are going to have some real problems with motor placement.
Remember the post I did on your board once.
"Cutting off you nose to spite your face" If you guys aren't careful that is exactly what you are going to do.
Andy I hope in jest brought up the Kawasaki 300x jet ski motor. I couldn't find any for sale but they are out there I am sure, other manufactures have similar motors, but that would require a drive shaft. Don't limit your options with rules. "I love competition" it bring out the best in all of us. If crazy guys like Mini and me want to experiment how is it going to hurt you or your racing group. These motors don't live for ever, the best 2010 motor you find on Ebay is going to have 10,000+ very hard miles on it, and you will spend $4000.00 dollars having somebody rebuilding it for you and it will still be a grenade.
Did I tell you about the used engines I bought off Ebay this summer. After blowing them up I did a little closer inspection. What I found was the left #1 main bearing was way out of round. They probably hit something very hard crushed, the gen cover, bent the flywheel and twisted the block out of square. The sellers replaced the cover and flywheel and probably did not even suspect engine damage. I SURE DIDN'T.
After the fact and after buying some expensive small hole bore gauges and doing a much closer inspection did the problem show up. If you used plastigauge to check the main bearing clearence it was dead on but checking the bore front to back they were as much as .003" too large. That is where my oil pressure was going after the engine warmed up.
Honest Dad himself

