Re: Changing jets to make more HP
A lower exhaust port increases the effective stroke, retards exhaust port timing, shortens the duration and increases the compression ratio. The exhaust port would have to be raised and widened to change the port-time-area peak for a higher rpm and require changes in the transfer ports.
right on...I measured one exhaust port and it was about 1.775"...but that is with a digital caliper by feel...because I was just using my finger tip to stop the end of the caliper
the 115 would be higher huh.....
what to do, what to do.....Ill rebuild first and sort that stuff out later
bob
A lower exhaust port increases the effective stroke, retards exhaust port timing, shortens the duration and increases the compression ratio. The exhaust port would have to be raised and widened to change the port-time-area peak for a higher rpm and require changes in the transfer ports.