I am thinking of switching from a 2 blade feathering MaxProp classic (17inch diameter 16 degree pitch) to a fixed 3 blade prop for my CAL 39 Mk2 with a 1.25 inch diameter shaft.
Would really like to know what other CAL 39 Mk2 owners have for a fixed blade prop.
I realize I would give up speed while sailing (maybe .5 knots) but I don't want to immediately drop $3,000 on a folding or feathering prop until I know what my engine (4JH4E) can provide as speed. With the Maxprop I barely make 5.5 knts at 2800 rpm.
Anyone have any recommendations for the fixed blade prop.
Gladly trade my MaxProp
Since we bought our 34 footer in 1994, we have used a two blade fixed prop, a two blade feathering prop for a decade, and currently are using a three blade ("sailor" narrow blade) fixed prop. We could never motor constantly over about 6.5 kts until changing to the three blade fixed.
Blade area is important, and so is the shape or 'cupping' on the blade.
Your feathering prop has a flat blade, so that it can feather; so did ours.
Adding more blade area (number of blades) is one way to get back some speed when using a feathering prop. While they are wonderful for sailing speed and will also reduce prop walk in reverse, they do have a trade off in efficiently going forward.
Matter of fact, if I can find about $2800. under the couch cushions I would order up a new three blade feathering prop, Max or Martec.
I looked up your engine model and it appears to have 55 hp. That seems like ample for your boat and with your waterline I would expect you to maintain better than 7 or about 7 1/4 kts in smooth water.
(Presumes a clean bottom, of course!)
By comparison, we motor at 7 kts with our shorter DWL and only 25 hp, and of course our three blade prop. Great for coastal passages but not as good for sailing speed.
So, some research seems in order.
Aside: a semi-pro sailor that I know has a very high regard for your model of Cal -- really good all around design.