Why 2-Stroke Direct Injection is a Big Deal
This article was written by Phil Mickelson at Snow Goer magazine. More in-depth information about fuel injection on two-strokes. While these are not motocross applications you can see how they could be adapted to MX bikes.
When U.S. Environmental Protection Agency regulations for snowmobiles started in 2006, Ski-Doo already had its 600 H.O. SDI two-stroke engine on the snow for two years. It was considerably cleaner than regulations required and it achieved industry-leading fuel economy. The engine was light, powerful, dependable and clean.
As the Bombardier Recreational Products (BRP) Evinrude group developed the E-TEC system for its outboard motors (BRP acquired Evinrude in 2001), it became clear that this technology could translate directly to Ski-Doo snowmobiles. In the winter of 2008, Ski-Doo released the 600 H.O. E-TEC engine.
Is the E-TEC engine a big deal in the world of snowmobiling? Absolutely. It demonstrates that the two-stroke engine — with all of the advantages it offers for snowmobiling — is far from being axed from snowmobile manufacturers’ product plans. The 600 H.O. E-TEC is available across Ski-Doo’s 2009 lineup and further expansion of the direct injected technologies will prove the strength of the two-stroke engine design and its attributes.
To read the complete article, please click on the following link;
http://www.snowgoer.com/output.cfm?id=1836523
Comments
By GlennCMcGovern on October 25th, 2009 at 2:19 pm
This is an amazing article. The two-stroke fuel injected engine with clean emissions seems to be in our future in motorcycles and possible cars if that 1000 cc two-stroke with 220 hp is possible. I love the dyno chart and believe that is easily possible to have the higher curve on the two-stroke curve over the equal size four-stroke. The question is though how useable is the powerband.
By 2STROKEREVOLUTION on October 27th, 2009 at 8:56 pm
With direct injection the powerband is equivalent to that of a 4-stroke. It is just as flat. A 250 2-stroke will have a powerband about the same as a 450 4-stroke. Just as much torque and power throughout the rpm range. So there will be no competition when comparing equal displacement bikes. And if a 250 has the same powerband as a 450 then the 250 has the advantage of weight and the 450 has no advantage.
What this article leaves out is the 600 E-Tec makes 130hp and gets 21mpg. The 1100cc Yamaha makes 130hp and gets only 18mpg and weighs 85lbs more.
By Sachsgs250 on December 1st, 2009 at 11:44 am
Perhaps someone could answer this question:How much does the parasitic drag of the valve train affect fuel economy in a fourstroke gas engine? What I am wondering is if this is partially responsible for the amazing fuel economy ratings of some direct injected two cycle engines?