I am changing from a three bladed to a two bladed prop to help my light air racing speed. I can quess, but it would be nice if someone actually had a spec on a prop that worked well racing and cruising.(dimensions, pitch, etc). I appreciate the help.
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Kiwi Props
The PO of my boat put one of these 3 blades on his Hunter 386 and can't say enough good things about the prop. He did say he could tell the difference when sailing in lite air. Good power in forward & reverse. I'm going to probably try and get one for my Newport 30 this spring. Go to Kiwiprops.co.nz they also have a dealer in Toronto, Ontario
The PO of my boat put one of these 3 blades on his Hunter 386 and can't say enough good things about the prop. He did say he could tell the difference when sailing in lite air. Good power in forward & reverse. I'm going to probably try and get one for my Newport 30 this spring. Go to Kiwiprops.co.nz they also have a dealer in Toronto, Ontario
Three blades or two?
I can't help with brands but I think I can offer some light on the benefit of the change. Calculate the blade area of your existing prop and calculate the blade area of the new prop that you will purchase. Determine the difference and find a tin can with that same area across the open end and rig a bridle on it. Go sailing in light air as you do now and check your boat speed, then drag the can behind the boat and observe the change in boat speed. If you are able also to lock a two blade vertical behind the keel you will do a bit better. If you lose a tenth of a knot while dragging the can then you will probably gain a tenth by going with two blades. this is not very scientific but may help. I went from a two blade to a three blade and can see any difference in the distance the boat carries when I shift into neutral. So I believe that the changes will be quite small. Ross in Bel Air
I can't help with brands but I think I can offer some light on the benefit of the change. Calculate the blade area of your existing prop and calculate the blade area of the new prop that you will purchase. Determine the difference and find a tin can with that same area across the open end and rig a bridle on it. Go sailing in light air as you do now and check your boat speed, then drag the can behind the boat and observe the change in boat speed. If you are able also to lock a two blade vertical behind the keel you will do a bit better. If you lose a tenth of a knot while dragging the can then you will probably gain a tenth by going with two blades. this is not very scientific but may help. I went from a two blade to a three blade and can see any difference in the distance the boat carries when I shift into neutral. So I believe that the changes will be quite small. Ross in Bel Air
Best Choice
After some rearch, I came to the conclusion that the 30T and 29.9 Seidelmann's would perform best (in the fixed prop world) with a 13X13RH fixed two blade prop. My current 13X10RH three blade is great and can easily push me into a strong headwind but it is too slow around the marks. I ruled out the folding and feathering prop designs because I would lose too many rating points. I need all the points I can get to compete against the lighter boats in my fleet. We will see what happens next season.
After some rearch, I came to the conclusion that the 30T and 29.9 Seidelmann's would perform best (in the fixed prop world) with a 13X13RH fixed two blade prop. My current 13X10RH three blade is great and can easily push me into a strong headwind but it is too slow around the marks. I ruled out the folding and feathering prop designs because I would lose too many rating points. I need all the points I can get to compete against the lighter boats in my fleet. We will see what happens next season.
Best Prop
I took my 13 X 13 two blade fixed prop off and replaced it with a Martek folding. The two blade was a great cruising prop as it could push my 299 in all conditions, but, as it turns out, was not the best for racing. My boat speed increased in light air after the exchange by more than the 3 seconds I gave up. I would go with a folding prop. Mine is a 12 X 14. Mark
I took my 13 X 13 two blade fixed prop off and replaced it with a Martek folding. The two blade was a great cruising prop as it could push my 299 in all conditions, but, as it turns out, was not the best for racing. My boat speed increased in light air after the exchange by more than the 3 seconds I gave up. I would go with a folding prop. Mine is a 12 X 14. Mark
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