Re: The best porting option for a 13b rotary engine.

"The Raven" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> "Felix Miata" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
 >
> > Overlap? Extending a port has no material impact on overlap.
>
> Sorry, it does affect overlap. Perhaps the extend ports used in the US
> aren't as aggressive as what is seen here.
>


I gotta go with Felix on this. The intake port opens well after TDC and
shortly after the exhaust closes. Attempts to open it sooner (without a
bridgeport) will result in the corner seal or side seal catching on the
trailing edge of the port. Extending the port closes the intake later, but
the exhaust port has been closed for eons. Advancing the opening of the
intake is the reason bridgeport came about, ain't it?

Chas Hurst