Prop Question

[dan miles]

Just read post about 3 blade props. I have C30 with Universal 25 and the standard 2 blade prop. I want to replace it at the nexr haul out. Which 3 blade prop does anyone recommend? I don't race, just want more power to push thru strong tidal currents in my area. Thanks Dan

 

[Tom Soko]

Autoprop or MaxProp

Dan,From what I've read, either the MaxProp or Autoprop will give you the best performance, but at quite a price (2.5 boat bucks). I've got the autoprop on my C36 and I love it.

 

[RonD]

3-Blade

I have a fixed 3-blade on my C320. It is considerably cheaper than the folding/variable pitch varieties, and delivers good power under most conditions. I don't find the drag to be worrisome (but I don't race).Talk to Catalina or your Engine dealer to determine the diameter, pitch & blade size needed. The diameter is mostly driven by the geometry of your boat. Pitch is a factor determined by the boat, the engine, and the transmission. Blade size/shape -- well, I'm not sure how that's determined.In spite of everything, this match is not an exact science. Some trial & error might be needed to ensure the prop is delivering the best propulsion power at the optimum engine RPM.As to brands, add to MaxProp & AutoProp the Flex-o-Fold and others. There are some posts in the archives worth looking at -- search on "props" for starters.--RonD

 

[PaulG]

another 3-blade

I bought a 3-blade prop called the "Campbell Sailor" from an outfit in British Columbia called West by North Enterprises for my C-30. It runs much smoother that the 2-blade and gives me hull speed 500 r.p.m lower that before, and I can't really tell that there's much more drag at all. I also don't race, though.

 

[SAM]

Contrary to Popular Opinion...

a properly sized and pitched 3 blade prop will not give you better (read that higher) speed than a properly sized and pitched two blade prop. From this, your two blade prop (if it is correctly sized and pitched) will give you the same performance into the foul current that you're asking about. However, the three blade prop will give you better acceleration. This is obvious when bashing into a chop or a strong headwind. In addition, it will stop the boat quicker when you put it into reverse.On the negative side, the three blade prop is VERY much worse sailing down wind than a two blade prop. When I bought my C-30T with a three blade prop, I couldn't wait for the season to end so I could get rid of that three bladed sea anchor and replace it with a folding prop.Upwind, you won't notice that much difference in sailing performance between the fixed two and three blade props, but down wind performance definitely suffers with three blades.

 

[Ken Juul]

Re: Prop

On my 34 I replaced the Michigan Sailor 3 blade with the Campbell. Extremely happy with it, much better performance in both directions. Much less surface area, so I'm sure sailing performance has improved, but haven't measured it. A co worker just installed a Kiwi feathering. about half the price of Auto/max prop. It has carbon fiber blades that can be changed in the water. Due to Hurricane Isabel he hasn't had it in the water yet, but was very happy with the install.