Two Stroke Motocross
Two Stroke Motocross Forum => General Two Stroke Talk => Topic started by: citabjockey on March 16, 2017, 07:32:29 AM
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Uniflow -- you get royalty checks for your transfer port injection invention???
http://enduro21.com/index.php/40-general/1966-ktm-officially-confirm-fuel-injected-two-stroke-enduro-bikes-due-may (http://enduro21.com/index.php/40-general/1966-ktm-officially-confirm-fuel-injected-two-stroke-enduro-bikes-due-may)
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Another link I read yesterday:
http://racerxonline.com/2017/03/15/fuel-injected-ktm-two-strokes-coming-in-2018
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Uniflow -- you get royalty checks for your transfer port injection invention???
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Yeah right, I'll wait by the letter box.
Kawasaki doing secret testing of their Euro4 TPI F9 last weekend in an NZ forest. Can you spot it;D
https://youtu.be/ZqzOgOJuJ1E
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While the money would be nice, it has to be a bit rewarding to have the design validated at that level.
--Ron.
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Well yes, perhaps I wasn't completely full of shit after all.
I'm keen to finish the RV 360 EFI engine, but I'm on the lookout for a YZ250 (04 onward) gearbox as I pinched the one I had for the sleeve valve engine. I have leads on two units at the moment.
I'm finishing up the cylinders (some spares) now, cast at home, next week off for nikasil.
https://youtu.be/UdSw3QbZtKE
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Dr. Flettnerstien's Monster
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I was talking to a KTM dealer service manager today who seemed to know a bit about the new system.
I asked about how they are going to oil it. He said oil injection straight to the bearings, but I have to think they are going to need to do some kind of mister system for the small end bearing / piston / rings.
How did you deal with the oiling?
--Ron.
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On the YZ we made a small solenoid operated valve that opened after 60% throttle, before the reed block. Ran a lean pre mix as well.
On my 360 I've got an oil pump (TS100 I think) feeding straight into the big end through the hollow crank shaft. Oil should leave/ fling off the big end and head for the cylinder and small end, mains sealed off.
On the DTPI Kawasaki, I just run pre mix as the injectors are in the crank case aiming at the transfer intakes. Seems enough oil is deposited to keep thing from going dry.
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WOW... holy chit... I will be watching intently to see how they perform...
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I am going to try to get KTM to let me ride one!
I'm not holding my breath mind you.
--Ron.
WOW... holy chit... I will be watching intently to see how they perform...
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I am going to try to get KTM to let me ride one!
I'm not holding my breath mind you.
--Ron.
That's awesome, good luck :) .
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KTM will gladly let you ride one -- if you hand them a check for $11k
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KTM will gladly let you ride one -- if you hand them a check for $11k
I was kind of hoping for a more economical introduction....
--Ron.
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https://transmoto.com.au/wp-content/uploads/2017/05/KTM20182TLaunch_49.jpg
See the three cylinder developments, starting with the DI Orbital system. Finishing with our own TPI seen on TSM five years ago.
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DI is the "future" but dang is sure looks complicated.
--Ron.
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Is Direct Injection the future?
It seems the DI Rotax sled engines now run injectors at the inlet port that fire once the pipe is 'on'. makes a bit of a mockery of DI. DI also has to start injecting before the exhaust port is closed as the revs increase, once again making a mockery of DI.
This TPI isn't as bad as everyone would have it (know it alls on the internet) with the gas dynamics in a twostroke its the lower end power (rpm) where the short circuiting takes place (hence DI systems not being pure DI up in the revs only low down), its the position and late firing of the B port injectors that save the day for TPI. This is where most fuel is lost to the exhaust on a carburetor engine and lets face it, where we ride our bikes most, off the pipe or at least in transition.
The real answer is to keep the transfer gas speed up at lower RPMs and lower the port timings (including exhaust port) in conjunction with a modified TPI system. Sliding cylinder anyone?Cylinder could do the throttling (power controlling) while the inlet would have no throttle body, just straight in through the reeds, so the crank case would always be under pressure. Always a good, high inertia, gas flow into the cylinder under an amount of control. This system would require my new TPI system to operate. Results would show a very wide torque curve and excellent fuel economy.
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Interesting, I always assumed the DI system to be more like a diesel system where the injection cycle happens very late in the power stroke hence the need for a burly injector to overcome the compression.
--Ron.
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Yes a large (burly) injector is needed because at some stage injection is taking place under compression. At higher speeds there is just not the time to inject and mix all the fuel with all the air, thats where Diesel comes unstuck. Cant process the injection and burn at high engine speeds, thats why they react so well to over boosting with air (turbo)but there is a time limit and thats why you don't see diesels doing 13000 rpm. Apart from the general size Im just talking burn wise. This is where HCCI has a major benefit, all air and fuel is already mixed so its just a matter of compressing it at the right time for combustion (controlled detonation). Hence my HCCI test engine, sown here already? Another project in itself. Yes sorry, we have talked about this already.