"trainfan1" wrote in message
et...
Bishoop wrote:
"mark" wrote in message
...

I have a 225 ficht on a 26' v bottom aluminum workboat and at 6000rpm the
3 blade only gave me around 35mph and the 4 blade again at 6000 gave me
42 mph, I was amazed because I thought the 3 blade would give a higher
top speed.


Were they the same pitch and diameter?



Of course not.

Rob

I don't belive so either. With the facts as they were presented, the laws of
physics would have to be rewritten.

In probably 99% of all installations a three blade with the same pitch (all
other things being equal) will be "slightly" faster than a four blade.