ORIGINAL: sigrun
Harry I suspect you may have reverse transcribed the figures you recorded. You aren't
seriously suggesting a square tipped MAS paint stirrer tachs 1000rpm
FASTER than an APC prop of the same diameter and pitch?
Sigrun, in the tests I've run, that's exactly what's happened. Two I can recall from memory...:
1) GMS .47 with Tower muffler.... APC 11x6 - 12,000 rpm; MA 11x6 - 13,800 rpm
2) ASP .46 with Tower muffler ... APC 11x6 - 11,800 rpm; MA 11x6 - 13,400 rpm
There is an enormous difference in load between the two 11x6s that is not necessarily applicable to MA and APC props in other size ranges (for example, the MA 12x6 and APC 12x6 provide a similar load to each other). This is why it's important to say what brand and model of prop you are using rather than a generic reference to its nominal dimensions.