What would be considered the acceptable RPM to compete in 428 for a used Q500 nelson with a 8.8 X 9 APC? I understand flying the plane around the poles to be the most important thing, but still would like to know what you guys consider acceptable RPM, or needs new sleeve, piston, whatever RPM. Thanks in advance for the comments.

I rarely run that prop, but if its turning over 19,300 you will be in the ball park if your motor is unloading properly.

RPM is not the end all.

thanks Dave, I don't want to start a prop thread, those go on forever. I just picked what I thought would be the middle of the road.

Here in Minnesota the 8.8x9 just doesn't do it .

8.75 yes
9.25 yes
9.0 no

Don't know why, just is, at least here in mud duck land

Thanks SS, what RPM do you guys find acceptable ?

depends on which Nelson it is.

The newest version is easy to spot versus the older ones

The new one has a 3/16" raised area right around the carb inlet. The older ones have the needle valve right near the opening.

The crank on the new ones has a very big hole in the middle

Look at the Perf Spec. web site for a comparsion

What daven says on RPM's is with the newer ones.

anywhere over 18,500 and up with give a scary ride.

Try a 8.8x8.5 to learn how to tune. then put the big wood on, open the needle a short 1/4 turn and try it.