Hello sailors , I am considering converting the original two blade prop on a 1980 Westerly Conway to a MaxProp. it's advertised as increasing control and maneuvering, something of particular benefit to me. If you have one, how do you like it?
Maybe SBO should get some ad money from Max Prop. 
Some good comments on this thread from earlier today.
Some good comments on this thread from earlier today.
You beat me to it. There's a ton of great info on SBO already on this - 300 threads popped up on a Maxprop search (though admittedly many won't be spot on for this question). I suppose one more won't hurtMaybe SBO should get some ad money from Max Prop.
Some good comments on this thread from earlier today.
Thanks for all your helpful replies.You beat me to it. There's a ton of great info on SBO already on this - 300 threads popped up on a Maxprop search (though admittedly many won't be spot on for this question). I suppose one more won't hurt
I installed one of those nineteen years ago. Took me a few years to get the pitch adjusted correctly by trial and error tweaking at annual haul out. In my case, I found the prop walk reduction in reverse claims to be exaggerated. With my fin keeled boat I still have prop walk but I have learned how to use it. The speed improvement claims under sail in low winds may be true in theory with the prop feathered but how to measure? The annual greasing and cleaning are easy enough. I have had no reliability issues over the last nineteen years and it works just as well today as the day I installed it. IMHO these props are very expensive but the improvements in boat handling and low wind performance over your fixed prop will only be subtle. Fine, if you can afford one.
I agree that the claims of propwalk reduction are overstated, but I think the increase in sailing performance relative to a fixed prop is definitely noticeable, at least to a racer. What hasn't been mentioned in this thread is the great improvement in thrust in reverse gear, very nice when docking. Also agree about using propwalk to your advantage.
We used a two blade feathering prop for a decade. The gain in sailing performance was both in speed, about 3/4 of a knot and in pointing angle - especially in light air. Reverse was straighter. Prop walk in reverse was less than with the fixed prop, altho not zero.
I love my MaxProp...I'm glad the previous owner of my boat was smart enough to purchase it, because I probably wouldn't have been! I have a fair amount of prop walk, which, like others, I find very useful.
Thanks again for all your user experience feedback. I just purchased this sailboat in a distant region. Personal experience is limited to the sea trial and comments read on the poor maneuverability of a heavy bilge keel sailboat. The two blade prop is original to the 1979 boat. On sea trial I noticed the owner worked quite a bit at manoeuvering to back the boat into the dock. The boat is back on the hard since then.
Now in preparation for moving the boat down to me, I am getting dry dock type jobs done.
The prop shaft has play. The cutless bearing needs replacing and there's no anode on the shaft. While I am getting these things addressed, swapping out the ancient prop seems worthwhile considering. That's my reasoning.
MaxProp is expensive and a big chunk of my pre-splash budget. However, prop efficiency affects one of the big three fundamentals on a sailboat in my opinion, those three being, engine, sails, steering.
I'm on the fence about switching to Maxprop and of course , I can do that at any future haul out.
Now in preparation for moving the boat down to me, I am getting dry dock type jobs done.
The prop shaft has play. The cutless bearing needs replacing and there's no anode on the shaft. While I am getting these things addressed, swapping out the ancient prop seems worthwhile considering. That's my reasoning.
MaxProp is expensive and a big chunk of my pre-splash budget. However, prop efficiency affects one of the big three fundamentals on a sailboat in my opinion, those three being, engine, sails, steering.
I'm on the fence about switching to Maxprop and of course , I can do that at any future haul out.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,746
This thread was focused on MaxProp as the tool. Now you are adjusting the query to identify performance properties with a budget for a specific boat type.
This opens up the question to consider other tools that can meet your requirements.
I would suggest you consider the CampbellSailor made by the company WestByNorth.
Low Drag Sailboat Propellers - West By North
West by North are specialists in low drag, feathering and folding propellers.We manufacture and supply propellers for any sailing boat, anywhere. The Campbell Sailer propeller is designed and manufactured to be one of the most efficient fixed blade sailboat propellers on the market today. Unique...
westbynorth.com
It is not a folding prop, it is a prop designed to have reduced drag. It has high thrust performance. Is optimized to your engine and transmission. It is in a cost favorable price range.
I made a similar criteria list when I was seeking a replacement prop. Foldable and adjustable props were on my list of possible products. Cost and sailing performance were high on my priority list. I feel, after 6 years of use the CS prop meets the performance demands on my boat.
I switched to a 3 bladed, Max-Prop 3 summers ago on my Hunter 376.
In my experience, beneficial claims of improved handling and reduced prop walk were greatly exaggerated.
THE GOOD: Shearwater gained a 1/2 knot of sailing speed in light air. Sadly, the improvement diminishes as the winds rise up.
THE BAD: We observe a significant decrease in straight line motoring. At least 1/2 a knot slower at optimum RPM. This came a complete surprise.
THE UGLY: The barnacles on the Hudson LOVE the MaxProp
In my experience, beneficial claims of improved handling and reduced prop walk were greatly exaggerated.
THE GOOD: Shearwater gained a 1/2 knot of sailing speed in light air. Sadly, the improvement diminishes as the winds rise up.
THE BAD: We observe a significant decrease in straight line motoring. At least 1/2 a knot slower at optimum RPM. This came a complete surprise.
THE UGLY: The barnacles on the Hudson LOVE the MaxProp
Propwalk in reverse is decidedly stronger than with a conventional prop due to the blade shape. This is an asset once you learn to use it.
This is to be expected. As the boat approaches its max speed, the reduced drag has less effect on the speed. A folding or feathering prop comes into its own in winds below 12 knots and when accelerating out of a tack.
This suggests the prop's pitch is not set correctly. Check with PYI for the correct pitch for your boat and engine. Resetting the pitch is not particularly difficulty, although messy. PYI has directions on its website.
Do they like the Max Prop more than other props? There are several antifouling treatments available for props and shafts ranging from under $20 to over $200. Have you tried any? The Barnacles may also be causing the decline in motoring performance. They certainly slowed us down as they moved in.
Any competent hull diver can replace your existing prop with any other prop (including Max Prop) while the boat is in the water. There is never a need to haul the boat for any prop-related maintenance or repair.
As for adjusting maxprop pitch; I found the best way is to dial the pitch up until your engine can no longer reach max rpm. Then dial the pitch back a notch or two. This should be done with a clean bottom and prop. This adjustment does not have to be perfect. Few, if any, original fixed props are pitched perfectly for that matter.
What is the recommended space between the hull and the tip of the prop?
My O’Day 322 has a 14x14-2 blade Michigan now. MaxProp recommended a 15x11-3 blade, but I have a bit of a skeg molded in the hull, and a 15” prop would be very close to the skeg.
I also need to see how much shaft you need aft of the strut…I don’t have a lot of shaft exposed.
Greg
My O’Day 322 has a 14x14-2 blade Michigan now. MaxProp recommended a 15x11-3 blade, but I have a bit of a skeg molded in the hull, and a 15” prop would be very close to the skeg.
I also need to see how much shaft you need aft of the strut…I don’t have a lot of shaft exposed.
Greg
The distance between the end of the prop and the strut should be about 1 shaft diameter, but it is not exact. For a 1" shaft you will probably be OK from ¾" to 1 ¼".
Distance between the prop tip and the skeg is pretty tight. I wouldn't want to close that gap. Measure the distance and send PYI the photo.
Distance between the prop tip and the skeg is pretty tight. I wouldn't want to close that gap. Measure the distance and send PYI the photo.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,746
I was going to say (from memory in talking with WestbyNorth) 10-15% OF PROP DIAMETER.
Then I thought better and just web searched for “Prop Tip Clearance”. Up popped this Link.
ab-marine.com
Maybe that helps.
Then I thought better and just web searched for “Prop Tip Clearance”. Up popped this Link.
propeller tip clearance
Learn how proper tip clearance ensures that your propeller gets attached water flow to work. Measure for tip clearance.
ab-marine.com
Maybe that helps.