I have a question regarding zenoah and QD
QD have better or best performance compare to zenoah in term of RPM and HP

is this because QD using liner?
if zenoah can be modified using liner, it will perform the same?

Wats needed is another good piston ported with liner 30.5 cc engine ! Who will make it?

No. Liner only will not do it. Has to do with the port layout and design of cylinder.

Todd

Quickdraw

And IMO, your engines are "King of the water" right now to show your right. But, to their credit, the bigger Zen engines (36mm bore and stroked) are capable of up to about 7hp, and that was very respectable on the water only about 1 year ago. Then you guys raised the bar again with your excellent porting and a big 36mm bore "Pioneer".

I was just wondering why you named the newer 36mm bore the "Pioneer", because it is not the "first" QD engine to dominate it's engine size. Then it hit me,---I see. It finishes first.

To the thread starter, IMO, it is the "bridged exhaust port" that is the main key. A bridged exhaust port should always be able to run stronger than a single exhaust port (of the same size engine) if both are optimally ported and piped. The QD stuff, with their pipe is pretty darn optimal, and they will always be hard to beat as long as we can run 2 stroke engines.