"Rick" wrote:
Back in my racing days I used a Martec II folding prop. It I remember right
I have been told that a folding prop and a feathering prop are
different. I haven't seen a folding prop, so I don't know what the
difference is.
(Martec recommended) it was a 14x12 and replaced a 16x10 2 bladed and worked
ok. It was on a Yanmar 2GM20F. Less power in forward and significantly
less power in reverse. You need to be much more aggressive in reverse when
docking. Lots more walk to port also. Still had to line up the shaft (I
used the keyway since the two were inline) to get it to fold in light air
since the weight of the prop would cause it to open. I have even heard of
folks jumping overboard and putting a rubber band around them to keep it
closed. If it got fouled with growth so it would not open all the way it
would let you know by vibrating when trying to go forward. This is just
some of the things you need to put up with when you race.
Yes, I sometimes go over to check and see if the prop is moving freely
and to wipe or chip off growth.
We had a 3 blade prop to start with, and we put on a 3 blade
feathering prop that was as close to the diameter and pitch of the old
prop as possible.
I believe it did fold when going from forward to reverse. You could hear it
go "clunk."
This is transmission dependent to a certain extent. Our transmission
goes clunk when going from forward to reverse. I can't hear the prop
feather. The only way we know if it has not feathered is that we can
still hear the shaft rotating.
With my current cruising boat I would look at feathering props if I were to
upgrade. I need a good reverse and these provide it.
I guess the question is did it help? I would guess so. Could I tell? No
not really.
I agree with JAX. There is quite a bit of stuff you can do to the bottom of
the boat for speed. But bolting on a folding prop is definitely easy. The
other speed improvements require hard work.
When our engine is running the shaft is spinning because we have a
Borg-Warner transmission. Our shaft spins whenever the engine is on
regardless whether it is neutral or not. The prop feathers when the
engine is turned off and the shaft stops spinning. The stopping of
the shaft spinning feathers the prop if I understand it correctly.
You really wouldn't want the prop feathered if the engine was on - if
it feathered when you went through neutral when docking or something
it would be very awkward.