Anyone using a flexofold 2 blade feathering prop

curriernh · **Joined:** 14 Jul 2011 07:14 **Posts:** 60

Nice. That's two sales Flex-o-fold lost because they were non responsive. I know they lost their New England Sales rep but they really seem to be dropping the ball on small sales like ours.

Tom
s/v Dulcinea
1984 T37 keel/cb #427

Ventured · **Joined:** 12 Oct 2010 23:30 **Posts:** 12

I've been meaning to ask a few questions, but not sure where to post but since this thread is kind of related...

I'm planning a 700 or so mile trip, mostly to weather and may end up motoring most of it. Currently I have a fixed two blade prob of unknown pitch and diameter. I'm still soldering along with a Westerbeke 40.

I'm curious if anyone had used both a 2 blade fixed and 3 blade fixed prop, and how much more thrust they got out of the 3 blade. If you had a 3 blade, what was the diameter and pitch? Normally I'm a sailor but I may be motoring this trip and am willing to give up drag for motoring performance.

What RPMs to you typically run a Westerbeke 40 at? And what kind of fuel consumption do you see at your chosen RPMs?

Thanks!

Velera · **Joined:** 29 Dec 2006 09:38 **Posts:** 656

If you are asking about a T37, it seems something in the neighborhood of a 16 or 17 inch with an 11 or 12 pitch. One of the issues is that there is no one answer precisely even for a one design boat in my experience. How I am loaded makes a difference in required pitch for optimum performance. When I was out on a two year cruise and heavy with fuel, water and tools, pitch was different than now when I am just local cruising by a bit. I think you will find that the three blade will produce more even thrust and less vibration than a two blade and be slightly more efficient under power and produce more drag when sailing. David Gerr's book on propellers is a great resource. You want to be able to reach max hull speed for your boat at max RPM of your engine. You want to cruise at 80% of max rpm so as to not destroy the engine by lugging or wasting fuel and wear by higher revs. If everything is set up right, your boat should consume .6 to .8 gal/hr. based on the math of fuel consumption in Gerr's book. Interestingly, this does not vary much by the type of propeller used according to Gerr and in my own experience. Hull cleanliness and whether you are towing a dinghy is more important.

sord · **Posted:** 21 Sep 2012 09:40

I have a KIWI feathering 3 blade and notice about .5 knot increase in speed forward and a lot more power in reverse. Price is right - I paid $1400 with an extra blade. I have had it 4 seasons. It can easily be adjusted in pitch and maintenance is minimal.

I have a Westerbeke 50

http://www.kiwiprop.com/index.htm

Tartan37.com

Anyone using a flexofold 2 blade feathering prop

Who is online