News for twostroke fans.

[sirch345]

This could be good news for twostroke fans:- http://www.motorcyclenews.com/news/2017 ... evolution/

Chris.

[lloydie]

New toy for next year

[mik_str]

Snowmobiles have been running this technology since 2004 (hence my finding its hyping quite humourous) when it was launched by Rotax under the name Semi-Direct Injection. It works well and cleans things up nicely (still smokes and ring-ding-dings on idle, however), but it's not DI.

Check out Rotax's latest DI snowmobile offering here: https://www.ski-doo.com/technologies/ro ... ngine.html

A derivative of this would be nice

[fabiostar]

Thank the lord himself.... its time they came back into every mans life

[bigtwinthing]

Snowmobiles have been running this technology since 2004 (hence my finding its hyping quite humourous) when it was launched by Rotax under the name Semi-Direct Injection. It works well and cleans things up nicely (still smokes and ring-ding-dings on idle, however), but it's not DI.

Check out Rotax's latest DI snowmobile offering here: https://www.ski-doo.com/technologies/ro ... ngine.html

A derivative of this would be nice

a great video, however all those great jumps you see, they done show any landing . Bit like my ski vids, take great air, don't show the crash at the end. Great engines though.

[sirch345]

Snowmobiles have been running this technology since 2004 (hence my finding its hyping quite humourous) when it was launched by Rotax under the name Semi-Direct Injection. It works well and cleans things up nicely (still smokes and ring-ding-dings on idle, however), but it's not DI.

Check out Rotax's latest DI snowmobile offering here: https://www.ski-doo.com/technologies/ro ... ngine.html

A derivative of this would be nice

Cheers for the info and link Micky

As much as I would like to see it, would a two-stroke road bike have a market in today's high cost of fuel I wonder Lets face it we have a few people on here who complain about the Firestorm's mpg

Chris.

[mik_str]

A modern DI two-stroke could easily have superior fuel economy. Let us not forget that the mechanical drag is much less in a two-stroke (no cam chains, cams or valves to operate), and there is virtually no pumping loss in a two-stroke either. The two-stroke's downfall has always been unburned hydrocarbons (ie. raw fuel being pumped out the exhaust port; which serve to simultaneously increase pollution and drive up consumption) but both of these are solved in a DI engine, making for an engine that is much lighter, more powerful while not being impeded by parasitic losses. Kind of makes me wonder why the world is not migrating to them. DI two-strokes have been in snowmobiles since 2009 and they are fantastic!!!!!!

[davebonline]

A modern DI two-stroke could easily have superior fuel economy. Let us not forget that the mechanical drag is much less in a two-stroke (no cam chains, cams or valves to operate), and there is virtually no pumping loss in a two-stroke either. The two-stroke's downfall has always been unburned hydrocarbons (ie. raw fuel being pumped out the exhaust port; which serve to simultaneously increase pollution and drive up consumption) but both of these are solved in a DI engine, making for an engine that is much lighter, more powerful while not being impeded by parasitic losses. Kind of makes me wonder why the world is not migrating to them. DI two-strokes have been in snowmobiles since 2009 and they are fantastic!!!!!!

Plus cheaper to manufacture I'm guessing?

[macdee]

What ever happened Bill Gates 2 stroke engine
It's was mad

[sirch345]

A modern DI two-stroke could easily have superior fuel economy. Let us not forget that the mechanical drag is much less in a two-stroke (no cam chains, cams or valves to operate), and there is virtually no pumping loss in a two-stroke either. The two-stroke's downfall has always been unburned hydrocarbons (ie. raw fuel being pumped out the exhaust port; which serve to simultaneously increase pollution and drive up consumption) but both of these are solved in a DI engine, making for an engine that is much lighter, more powerful while not being impeded by parasitic losses. Kind of makes me wonder why the world is not migrating to them. DI two-strokes have been in snowmobiles since 2009 and they are fantastic!!!!!!

I appreciate how far the two stroke design as come from what it used to be like, they have made massive jumps in technology there. I can't help thinking though, can a two stroke engine be competitive with a four stroke in the fuel economy stakes when it fires twice as many times as a four stroke engine Or I'm I missing something,

Chris.

[mik_str]

The answer to your question is yes it can. In fact, it can get better fuel mileage because a two-stroke, due to much less mechanical drag (no cams turn or valve to open), as well as having virtually no pumping losses. Again, the big issue with two-strokes has always been raw fuel being pumped out the exhaust port, and this is cured with DI tech.

[sirch345]

The answer to your question is yes it can. In fact, it can get better fuel mileage because a two-stroke, due to much less mechanical drag (no cams turn or valve to open), as well as having virtually no pumping losses. Again, the big issue with two-strokes has always been raw fuel being pumped out the exhaust port, and this is cured with DI tech.

According to your link:-

fuel (up to 19 mpg

If in road going form they are so good as you say, the question has to be, why haven't manufacturers jumped onto this before now, or may be they are in the process of

Chris.

[mik_str]

mileage is all relative. Snowmobiles, being tracked vehicles, have a tremendous amount of friction (ie. approx half of the engine power is used up in the drivetrain), which severely harms fuel economy. For comparison purposes, I have had sleds that got 9 mpg (Imperial, not US), as opposed to this sled which gets about 21-22 (again Imperial, the quoted figure is in US gal, which are only 3.78 L). Put in such a low-friction environment as a motorcycle the fuel mileage would be incredible (remembering, of course, you are dealing with an extremely high performance engine), to say nothing of the performance.

as for why no one has jumped on board, good question, and one I have often asked myself. As the particular E-TEC voice-coil DI injector is patented, it would require BRP to step up to the plate or have someone else license it from them. I hope someone does, because this is too good to limit to sleds (and outboard boat motors). Dirt bikes and sportbikes with this tech would quickly have people forget four-strokes......

FWIW, I have been working in the snowmobile industry for the past 18 years, including the last 10+ as tech editor of a snowmobile publication (also did a 2 year stint as editor of a motorcycle mag, one I still write for as a contributor). I have talked at length with the engineers behind this technology and have sampled every sled built in the past 16 years, so I have a pretty good basis for my statements and opinions.... Here is the link to an article I wrote about the basic E-TEC technology when it first burst onto the scene back in 2005: http://fcmq.qc.ca/files/6614/7023/4147/ ... 005_12.pdf Things have continued to evolve since then, but the basic tech remains very similar...

[Pete.L]

If in road going form they are so good as you say, the question has to be, why haven't manufacturers jumped onto this before now, or may be they are in the process of

I think I recall reading something about this a couple of years ago and I'm pretty sure the answer is because two strokes over a certain cc were banned and now there isn't a legislative way to get them back on the market. I'm pretty sure this was written by one of the snowmobile companies. They had an 800 cc engine producing more power with less emissions than a standard equivalent four stroke engine and they were complaining their techknowledgey was basically being quashed by government and big industry

Pete.l

[mik_str]

If in road going form they are so good as you say, the question has to be, why haven't manufacturers jumped onto this before now, or may be they are in the process of

I think I recall reading something about this a couple of years ago and I'm pretty sure the answer is because two strokes over a certain cc were banned and now there isn't a legislative way to get them back on the market. I'm pretty sure this was written by one of the snowmobile companies. They had an 800 cc engine producing more power with less emissions than a standard equivalent four stroke engine and they were complaining their techknowledgey was basically being quashed by government and big industry

Pete.l

the Hondas of the world... just like they succeeded in making GP racing all four-stroke...