Re: 2 stroke lubrication--how?
Hey Dingbat! make sure your pipe is tuned to the correct length--remember: they are only good for a narrow RPM band.
Bob: Two cycle racing engines and to a lesser degree, all two cycle engines of the outboard type are typically overscavenged--that is, part of the fresh charge will exit the exhaust. This happens because both the bypass and exhaust ports are open at the same time.The tuned pipe takes the exhaust pressure wave and REFLECTS it back to the exhaust port JUST before it closes. Since the bypass port is already closed, the fresh charge is forced back into the cylinder and a mild supercharging effect is achieved. HOWEVER: since the pipe is a defined length and it takes a finite time for reflection, the pipe is only good for a small range of RPM--usually maximum.
BTW: This principle of reflection in a length of pipe was discovered by a Polish physicist, Felix Coanda and was originally known as the "Coanda effect." The original pipes were trumpet shaped. Years later in the 60s, another Polish model airplane speed racer, Ted Wisniewski actually developed a tuned pipe with essentially the currently accepted shape for his racing engines and set NUMEROUS speed records. The Japanese "borrowed" from him and put pipes on their dirt bikes.
"Bubble Back" OMC V4 engines used a version of this principle.
As far as oil, when the oil is mixed with gasoline it does not stay mixed, When the gasoline is vaporised in the carb venturi, the oil having a much higher vapor pressure assumes a micro-droplet mist. This mist is whacked around the interior of the crankcase and lubricates everything moving. Ball, Needle, and Roller bearings require very little oil to function correctly and the two cycle gives the the BEST environment: A fresh charge of oil with each revolution.
And that's the story of life!
