KawasakiTrax Community
General Category => General Discussion => Topic started by: Flying Frenchman on December 03, 2017, 10:59:29 AM
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Hi Guys its been a while. Now that harvest is over and there is snow on the ground its time to start thinking Race sleds.
Just got my 340 invader engine back from getting ported and the heads done. Was wanting to run Premixed C12 fuel in it but still want to run the injector pump in the idle position to lube bottom end. Does anyone know if I plug the injector lines to the intake if the crankcase will get to much oil? As in the extra oil that should go to the intake would flood the bottom end? Any Advise would be appreciated.
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Each of the injector discharge ports are fed by discrete alignment of the pump barrel with the discharge port. When the pump barrel rotates to be in alignment with the port, the pressure reserve is released into that port. While I have to believe that more oil will be distributed per pulse if there are no other outlets, the pulse duration is so short that the variation would likely not be much. The only way to know for sure would be to take a measurement by the procedure in the manual.
The feed from the pump barrel comes through the holes in the side of the barrel. These holes are visible in the attached photo - which happens to be of a worn pump. Pumps in good condition will show no wear at the hole location.
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I have a invader motor that uses pre-mix. You have to drill equivalent holes for the inside bearings as the outside bearings have. The motor appears to have been designed for either as the there are indents where you have to drill.
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I am working on building a 440 LTD Monohead, also converting to pre-mix - was happy to see this thread. Just got the crank out yesterday and sending it for balance. Similar requirements? Would a chamfer on the piston skirts achieve the same oil bath for the outer bearings?
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Why would you prefer pre mix to oil injection? Just wondering as it seem like one more step.
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I don't get it.....my 550 went over 7400 mi before rebuild....seems pretty reliable to me
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Mixing gas is towards the top of the list of my least favorite things to do...
If the oil pump, tank, and lines could be removed I could see an argument for weight savings but the crank must be oiled, so the injection system must stay. I can't see a reasonable reason to delete it.
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My project is entirely experimental and it seems like I'm always fighting with that oil tank. Not sure what Flying Frenchman has cooking.
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driving the invader waterpump is a issue with no oil pump......
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When running pre-mix you have one oil/fuel ratio throughout the entire throttle. Pre-mix doesn't take into consideration the needs of the engine. At idle it's rich with oil and at top end, where the engine needs the most lubrication, it's lean for oil.
Also, running pre-mix will change your fuel to air ratio because instead of pure fuel going through the jets in the carb you now have some of that fuel being replaced with oil.
Oil injection allows a variable ratio as oil is needed. At idle the gas to oil ratio is 100 to 1. As throttle is opened and the engine is working harder the ratio changes with engine needs. At 3/4 throttle and above the engine gets about 25 to 1.
This is one reason we can get such high engine mileage for a racing engine.
There is absolutely no good reason to partially block or remove the oil system.
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Good Morning Guys, Thanks for all the input. The reason i am thinking of running premix is for two reasons, 1. I have just spent quite a bit of money getting this engine race ready and want to make sure it doesnt pile up due to a faulty oil pump or something like that. 2. I have 3 other race sleds in my trailer on race weekends and we all run C12 race fuel and those sleds all run premix so it would make the pit crews lives easier if there was only one jerry can.
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I see your point....how will you drive the water pump?
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My Plan is to leave the oil pump in the idle position to still run a little oil to the middle bearing because it will not get oil from the fuel mixture. I want to disconnect the two other lines and plug them off. I think this should be safe?
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In 25+ years of running/working on oil injected Kawasaki sleds I have never had an oil pump fail.
I've never removed or disconnected a pump but if I ever had to I would leave it connected to the throttle and re-route the cylinder lines back to the oil tank. That way the bearings and the center seal would be receiving the proper amount of oil.
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While I generally prescribe to the theory that "it is your sled, you can do whatever you want to it", the philosophy of oil addition is one that can generate some strong opinion. I for one would really like to know what the Kawasaki engineers were thinking when they built these engines as there are some things about them that I don't immediately understand, and even after a few years of playing with them still don't understand. For instance Invaders and Intruders are essentially identical. But, there are side shields on the crank of the Invader but not the Intruder. Why is that? Also, the Invader gets an oil line to the center of the crank case. Why not to the right and left side bearings? Lastly, for the cranks that I have disassembled, I cannot find an oil path from the outside of the crankcase to the inside of the center seal. By the grace of God these conundrums do not keep me awake at night. And regardless of the reasons, they seemed to know what they were doing. Many, too many, of our sleds have come to us with the oil pump disconnected and residue of pre-mix in the carbs. We take them apart, replace the crank seals, put in some new pistons, use new carb boots, and hook up the oil pump and away we go. We have found one or two bad pumps on sleds that were really abused. But in the final analysis, all of our sleds run on the pump and I have never regretted not needing to mix oil and gasoline.
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the side seals help contain the oil bath on the center mains, I presume to help engine life with the extra 1k rpm.[vader vs. truder]
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Hi,
I believe the reason for the center oil inlet is mainly for the center seal. I suppose the crankcase could be machined to accept a conventional center seal but that would involve splitting the crank to replace it for rebuilding.
I get a headache reading about the math, science and engineering behind these amazing engines.
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IMO, the best argument for leaving the oil pump is the changing ratio based on throttle position. But, this T7 engine can be run either way. They used this same bottom end in arctic cat free air using pre-mix.
the only mod for pre-mix is drilling two holes in the top case precisely where the outside bearing holes are. this is to lube the center bearings primarily, but it will get to the center seal as well.
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see attached image from JDsleds site.