Exhaust Valved 2 Stroke Engine
My newly designed motorcycle engine is just a 2 stroke, without a standard exhaust port, with four in-head cam-controlled exhaust valves somewhat like a 4 stroke engine. But it really has the best of both designs since it has the power and throttle response of a 2 stroke, and the powerband and lack of harmful emissions (unburnt fuel) of a 4 stroke. Since it exhausts twice as frequently as a 4 stroke engine it may have a problem with overheating of the exhaust valves though. Besides changing the design to help it dissipate the heat more readily what could be done is have only 2 of the exhaust valves at any one exhaust-time open. The cam could have the front two valves alternate in action with the rear two valves. (Each set could open every other engine cycle.) The valves need to be lubricated with transmission oil, while the piston and crank assemblies need to be lubricated with oil premixed into the gasoline fed to the carburetor. To aid in the expanded powerband it is recommended that my new design of reed valve is employed in this design also. Crank degrees of actuation of the exhaust valves are recommended values, but only as a starting point for this new design. Variations from the initial values need to be experimented with to find the settings optimal for best horsepower, powerband, and emissions. A 4 stroke type exhaust pipe needs to be used with this design.
Engine Design Author: Michael David Forrest
contact info: email at firstname.lastname@example.org
see the fuel injected diesel version of this design at http://auto.howstuffworks.com/diesel-two-stroke1.htm
This link was given to me after I posted this page on dirtrider.net