A very very trick set of four blade 15x31's. Same as the ones I sold to Don (maritime) that he has had so much success with
msm
12-11-2009 11:15 AM
Blade Rake
Originally Posted by Brad Zastrow
(Post 3000614)
I guess I have been out of the outboard stuff too long. When I ran the four blade props I lost 5 mph. I would think running 5 blade props will allow a little higher engine height that would offset the stern lift problems I witnessed. The racers are using five blade props but I have yet to see them on a pleasure boat. Maybe that will change now. I am curious what the top speed differences are for three, four or five blade? I was just in a 120 mph 28 Skater a few weeks ago that my friend owns and he runs three blade Mercury lab 15 x 34.
Since rake contributes to a prop's bow-lift / stern-lift characteristics, I wish it would be stamped on the propeller in addition to the amount of pitch. I really don't think the stern lift you mentioned was due to the addition of another blade, but more likely less rake.
