The September issue of Dirt Rider Magazine, has a nice article on the future of engine design. They interviewed a couple of guys from Yoshimura. I will give a short review of the article, for those who have not seen it.

There is a "trickle down" of technology, starting with the superbikes. "The technology housed in one cylinder of the average four-cylinder superbike is basically what we have nested in the frame of the current crop of four-stroke motocross machines." (Unfortunately for us, ATV's are at the bottom of the pecking order! We tend to see the technology last, after it is already well established in the dirt bike lineup...........)

<u>An outline of some future trends:</u>
Weight Reduction- Not only the engine itself, but the "reciprocating mass" of the engine's moving parts. Lighter parts means quicker throttle response and higher rpm's. But, you can only go so far. Get too light and parts will break, and high revving engines can mean a loss of tractability.

Electronic Fuel Injection- No rejeting for changes in altitude and atmospheric conditions.

Engine Friction Reduction- Plain bearings, because ball and needle bearings have their own reciprocating mass and a higher degree of friction. Special coatings, will reduce friction and allow designers to lessen the piston/ring tension without compromising it's ability to seal. Gear driven cams, will eliminate the need for a chain. Lighter, more precise hydraulically or pneumatically actuated valves, with no springs. "When you reduce the friction, you also reduce the wear factor of the moving parts", thus, increased reliability and durability!

Smaller Displacement Engines Will Deliver the Same horsepower- Look at the little CRF250 which is getting 30 hp. That is more than a 400EX!

Twin Cylinders With Two Small Pistons- Twins rev more quickly than singles.

As in everything, the cost/benefit ratio has to be considered. "Cost is certainly a limiting factor for the incorporation of new technology".

Great article on "plain bearings"- http://mototuneusa.com/circular_logic.htm

 

I think they'll have to push the four stroke tech, thats the only thing there going to have in a while

 

Thanks for sharing that. I wish some of the quad magazines would get a bit more technical with some of their articles.

I think fuel injection will be the next big thing. I just HOPE that they keep it pretty simple. I'm keeping my fingers crossed that they don't clog up the injection computer will all sorts of emissions crap. Again, if they keep it simple, it will be a good thing....especially if the average home mechanic can hook the ATV computer up to his/her laptop and troubleshoot at home.