Duke Engines...Good for sled?

[m1kflyingtiger]

Did some searching on the crazy interweb and came across these "rotary" engines. Supposedly a significantly better design than the current offerings.

I figured you Yami guys with more 4 - stroke experience might be able to shed some insight on weather or not its a good option for a sled?

http://www.dukeengines.com/

 

[icr]

They'll be able to take boost well, I don't think they will be lighter than current four stroke offerings or even market them in a displacement small enough for motor sports.

 

[m1kflyingtiger]

In the aircraft section of their website they have a 100 hp and a 180 hp version. Both are listed at 101 lbs. what does a nytro motor weigh?

 

[BigFish BC]

In the aircraft section of their website they have a 100 hp and a 180 hp version. Both are listed at 101 lbs. what does a nytro motor weigh?

about 110-115 with throttle bodies

 

[icr]

I missed the aviation section. That sounds slightly lighter than a nytro motor, although the 180hp says it needs a gear box which would add weight. I don't know that it would need it for a sled application.

 

[Snowmixer]

Funny that this is mentioned in the Yamaha 4-stroke section, as I read recently that Yamaha was awarded a patent for a stratified six-stroke engine on February 26, 2014. If I remember correctly, two of the benefits of this type of engine were increased fuel efficiency, and the ability to make more power with a lighter weight engine.

I remember seeing an interview with someone from Yamaha last year, they were talking about sleds and he wouldn't elaborate but said, "The best is yet to come," or something to that effect. Obviously that statement could mean anything, but combining it with the recent six-stroke engine patent makes me hopeful that Yamaha really does have something groundbreaking (or at least an improvement in many ways) on the horizon.

Here's a little more about the patent:

http://www.freshpatents.com/-dt20140814ptan20140224195.php

 

[m1kflyingtiger]

I just assumed the gearbox would be the clutches and chaincase, the same as every other sled.

Found the MYT motor later on in my search. He's still looking for an investor to throw 100 million his way before he develops it and isn't interested in selling the patient, but amazingly simply, yet awesome design. http://peswiki.com/index.php/Directory:Massive_Yet_Tiny_(MYT)_Engine
http://www.angellabsllc.com/mytengine.html

 

[m1kflyingtiger]

Funny that this is mentioned in the Yamaha 4-stroke section, as I read recently that Yamaha was awarded a patent for a stratified six-stroke engine on February 26, 2014. If I remember correctly, two of the benefits of this type of engine were increased fuel efficiency, and the ability to make more power with a lighter weight engine.

I remember seeing an interview with someone from Yamaha last year, they were talking about sleds and he wouldn't elaborate but said, "The best is yet to come," or something to that effect. Obviously that statement could mean anything, but combining it with the recent six-stroke engine patent makes me hopeful that Yamaha really does have something groundbreaking (or at least an improvement in many ways) on the horizon.

Here's a little more about the patent:

http://www.freshpatents.com/-dt20140814ptan20140224195.php

Interesting concept for sure. I could see how it would get a better burn, but curious about how much more loss there is in the motor by the other cylinders compressing the air in the "compression without combustion" stroke and then that cylinder not helping with the power stroke till its next time around. Maybe pairing it with the cross-plane engine would make it a non-issue...

 

[icr]

I just assumed the gearbox would be the clutches and chaincase, the same as every other sled.

Found the MYT motor later on in my search. He's still looking for an investor to throw 100 million his way before he develops it and isn't interested in selling the patient, but amazingly simply, yet awesome design. http://peswiki.com/index.php/Directory:Massive_Yet_Tiny_(MYT)_Engine
http://www.angellabsllc.com/mytengine.html

Apex has gear reduction which is part of the reason it's heavier than a nytro motor.

 

[Jago]

Very interesting to learn in the patent that the two extra strokes in the cylinder effectively stop the intake air movement and concentrate it right in the rounded head next to the fuel injector. Then a smaller amount of injected and atomized fuel is needed only in close proximity. This air concentration phenomenon also permits a very different and simpler air intake design that can be optimized for more air throughput. (remind you of the turbocharging concept?) The claimed result is more hp and fuel efficiency vs four strokes. The patent (at least in a cursory read) also seems to suggest a very integrated turbocharger to help move more air through the engine and the charger benefitting from a lower average exhaust gas temperature than a 4S.

I wonder if they can make a 2 cylinder six stroke? Bring it on Yamaha!

 

[stingray719]

Not the first use of Rotary engines in snowmobiles though, pictured is a 1969 Polaris with a 303 Wankel. Arctic cat put them in sleds most of the early 70's.

http://www.snowest.com/forum/attachment.php?attachmentid=244309&stc=1&d=1418491052