Brian,


A 13x7 on an OS.46LA???

I would recommend this to no one. Not in a Diesel conversion and certainly not in a standard glow.

This would very likely cause overheating and even 'egged out' rod bearings.

It is sort of like running your standard shift car in top gear, uphill, at 30 mph... at full throttle.


This cannot sound very good, can it?


Model engines run best when peaked to achieve their maximum real HP RPM, in high speed flight.

Most .46 sport engines with the standard silencer they come with, usually top out around 14,000 RPM.
This means they should be propped to about 12,500, on the ground, for best all-around performance.

Not to 8,500 RPM...