Exhaust Duct

[LohringMiller]

Attached is a concise version of what I've been saying about the exhaust transition from the piston to the pipe.  It only applies to engines with large exhaust ports, not Zenoahs or their clones. 

Lohring Miller

View attachment Wobbly on Exhaust Port Duct Design.pdf

 

[Jim Allen]

I think this is one reason that QD engines can run strong. The first place that the incoming water goes is around the exhaust nozzle which is aimed downward & it is tapered.

JA