Good day all. I’m considering a prop change. We are planning the great loop that would entail more motoring than normal. I’ve always had an issue with not attaining the RPMs Yanmar wants the motor to and thought I would solve that issue as well. Dose anyone have experience or recommendations. Thanks
Prop change
- Thread starter Tom K
- Start date
Simple answer, get a Max Prop. These are not inexpensive and they can be adjusted to match your engine and transmission. What you will find is increased speed while sailing when the prop feathers and improved control while docking or maneuvering in tight quarters due to the prop walk in reverse. It will take a bit to get used to the new performance in reverse, once you learn it you will not want to go back.
There will be a lot of motoring, however, a lot of the Great Loop can be sailed, Chesapeake Bay, Delaware Bay up the Hudson, through the Great Lakes, and once in the Gulf of Mexico back to Southport.
The Tech support from PYI is excellent and they can provide the settings for the prop.
pyiinc.com
There will be a lot of motoring, however, a lot of the Great Loop can be sailed, Chesapeake Bay, Delaware Bay up the Hudson, through the Great Lakes, and once in the Gulf of Mexico back to Southport.
The Tech support from PYI is excellent and they can provide the settings for the prop.
PYI Inc. | Max-Prop Automatic Feathering Propellers
Max-Prop is the leader in automatic feathering propellers. From 2, 3, 4 or even 5 blade designs we have a Max-Prop to suit your application.
The Max Prop is a good prop. A fixed blade prop is also an option. I'd suggest you also look into the Campbell Sailor.
I'd say it depends upon your budget and what you think you want for a prop.
I run a standard fixed three blade on my boat and like the reliability. If I were to think I needed either a second prop or wanted to upgrade, I'd go to the Campbell Sailor.
dj
I'd say it depends upon your budget and what you think you want for a prop.
I run a standard fixed three blade on my boat and like the reliability. If I were to think I needed either a second prop or wanted to upgrade, I'd go to the Campbell Sailor.
dj
+1 for the Max Prop. As Dave said, it is adjustable, so you can fine tune the pitch to match your engine. I have made small pitch adjustments to my 3-blade MaxProp the last 2 off-seasons to get the best RPM/speed from my little Yanmar 2GM20F.
Also, the reverse thrust is really strong.
Greg
Also, the reverse thrust is really strong.
Greg
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,804
Hi Tom. You are planning a great adventure.
Most of my sailing is on the Pacific Northwest inland waters vs open Ocean. There are conditions such as tidal currents and choppy waters in remote locations that prioritize simplicity and performance under power over maximizing sailing performance.
For the above reasons I chose a Campbell Sailor manufactured by WestbyNorth in BC Canada.
westbynorth.com
The MaxProp is an excellent product. Maximizing sailing performance by adjusting the blades to minimize drag. The rotation of the blades improves the performance of the prop when going in reverse over other folding prop designs. While the engineering is robust, the prop requires maintenance every 1-2 years and a foreign object strike to the prop blades can create damage that incapacitates the prop mechanism.
The Campbell Sailor offers excellent value for cruisers prioritizing power, simplicity, and lower cost (about 40%) without sacrificing too much sailing speed. My experience is a reduced sailing speed of between 0.5-0.75 knts from hull speed in known wind and sea conditions.
Boat decisions often involve compromise. Check them both out and make your selection based on the waters you plan to explore and the demands you are going to make of your boat during the journey.
Most of my sailing is on the Pacific Northwest inland waters vs open Ocean. There are conditions such as tidal currents and choppy waters in remote locations that prioritize simplicity and performance under power over maximizing sailing performance.
For the above reasons I chose a Campbell Sailor manufactured by WestbyNorth in BC Canada.
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
The MaxProp is an excellent product. Maximizing sailing performance by adjusting the blades to minimize drag. The rotation of the blades improves the performance of the prop when going in reverse over other folding prop designs. While the engineering is robust, the prop requires maintenance every 1-2 years and a foreign object strike to the prop blades can create damage that incapacitates the prop mechanism.
The Campbell Sailor offers excellent value for cruisers prioritizing power, simplicity, and lower cost (about 40%) without sacrificing too much sailing speed. My experience is a reduced sailing speed of between 0.5-0.75 knts from hull speed in known wind and sea conditions.
Boat decisions often involve compromise. Check them both out and make your selection based on the waters you plan to explore and the demands you are going to make of your boat during the journey.
Where did you get this information, it is grossly inaccurate.
The Max Prop is a feathering prop that uses flat blades. Unlike other folding, fixed, and feathering props using shaped blades, the Max Prop developed more thrust in reverse because of the flat blades. The prop also offers less resistance when feathered thus improving speed when sailing. The flat blades are slightly less efficient when motoring forward, however this is negligible and a small price to pay for the improved sailing speed and greater thrust and prop walk in reverse. The reverse prop walk is especially helpful when maneuvering in tight quarters or when polishing the keel on a sandbar.
The prop does require routine maintenance which consists of greasing the prop every few hundred engine hours. A job that requires removing a set screw, inserting a zerk, and using a grease gun to insert grease. It is about a 10 minute job. A 10 oz tube of the recommended grease is good for about 9 or 10 servicing.
Like all feathering and folding props, the moving parts do wear. After 33 years and about 3000 engine hours I sent my prop in for servicing, there were 2 parts needing replacement. While expensive, amortized over the 33 years, it amounted to less than $30 a year.
As for getting damaged by striking a foreign object, any moving prop can be damaged by striking a foreign object. That is hardly an indictment against Max Prop.
If you are going to criticize a product, at least be accurate about the "facts" being used. I don't know where you got your information, it does not seem a reliable source, and it is not at all consistent with my experience with a Max Prop, nor the many friends I have who also have Max Props.
Just a note.
My fixed blade prop is 41 years old, is on its second engine driving it, and still looks like new. The only maintenance I do is clean it every time I'm also cleaning my hull. Now obviously I've never hit anything with my prop...
Folding props, in my opinion, are really best used by racing boats. There was a study done - I'm not sure if it was posted here on SBO a few years ago or where I read it but I apologize I don't have a link to it on hand - that quantitatively measured the actual decrease in sailing speed between a fixed blade and feathering prop. As I recall, there was a measurable hit in boat speed at low wind speeds and again at the top end of wind speeds, IIRC. But the middle range of wind speeds showed there was very little difference.
The Max prop is an expensive prop. It does require maintenance over time. I'll also add that if I were to go to a folding prop - I would choose the Max Prop as I feel it is the best folding prop out there.
However for my sailing, which is 100% cruising, I don't need the added maintenance, the added cost, and prefer the added reliability of a fixed prop.
dj
If you are not developing the expected rpms, then the prop size and or pitch is incorrect. A good prop shop might be able to help you determine the correct size and pitch and if your existing prop can be modified to get the correct pitch. You'll need to provide the boat size and displacement, engine HP, transmission ratio, and the distance from the center of the prop shaft to the hull above it.
If your existing prop cannot be modified, then you have a choice to go with a folding/feathering prop or a fixed blade. Each has its own advantages which have already been identified. My preference, as an astute reader might have surmised, is the Max Prop. Others have come to a different conclusion. In the end it is what is best for your intended use and your budget.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,804
My statements are from my research when looking at a prop. This included inspection of the unit. I further read the manual to understand what the manufacturer recommends for maintenance.
MAINTENANCE
The propeller must always be completely filled with recommended Lubrilate 130AA grease.The propeller should be greased at least once a year. This can be done with the boat in or out of the water.
Make sure that you always keep the zinc anodes in good condition. They must be replaced at least once a year, even if they still look ok. The propeller must be protected by a lot of zinc, so also use a zinc on the shaft when possible. When replacing it make sure that you clean the surfaces between the zinc and the propeller shaft in order to have a good electrical contact.
Your mention of improved speed at high wind sounds like you might be remembering my observations switching from a fixed prop to a Flex-o-Fold. This is the graph of my boat speeds relative to wind speed. Orange dots are my original fixed prompt; blue is the Flex-o-Fold. Solid lines are the best-fit curves.
The split at higher wind ranges is probably pretty unique to my model of boat where the turbulence in front of the rudder causes rudder stall at high loads. The lower two thirds of the wind range are probably more consistent across other models of boats. We do lots of Chesapeake sailing, including casual racing, where the half knot extra from the folding prop is nice.
As much as I like the Flex o Fold for the type of sailing we do it is necessary to find the right tool for the job. For trade wind sailing there's probably not much advantage in a folding prop, although the Flex O Fold has basically no extra routine maintenance requirements, and the folding mechanism is robust enough I'd have no concerns about its durability, so there's not really any downside to it either. For the type of trip the OP is planning the MaxProp might be a very good option - its sailing drag is not quite as low as a folding prop but its power motoring is generally better than even a fixed prop, and its maneuverability and power in reverse (for example when docking in unfamiliar marinas) is much better.
That's interesting data. How are you recording it?
Some marinas really do not provide a lot of maneuvering room. In Daytona the fairway to our slip was not much wider than our boat was long and there were several boats encroaching into the fairway reducing the width even more. With the Max Prop we were able to easily turn the boat into the slip and align it with the finger. Like wise backing out was easy because the prop walk let us turn the boat without making any appreciable headway. That's just one of many memorable docks along the east coast of the US and Canada.
Was in a similar situation in Portland Maine, over shot the slip and had to turn around surrounded by very expensive Sabre and Hinckley motor yachts. No problem until I lost reverse and couldn't get it out of forward.
I have a Raspberry Pi running SignalK connected to my NMEA network. SignalK saves all of the NMEA data into a database, and then I can query the database for different time periods. If I remember right the points on that plot are about four years of data, filtered to times when I was racing (so not just casually trimmed) and when apparent wind angles showed a beat.
There are some factors that are hard to control for. We had the fixed prop when the boat was brand new and converted after a couple years, so it’s possible that by the time we converted to the folding prop we’d learned how to get more performance out of the boat. Offsetting that the sails were probably a little bit more worn and stretched in the folding prop years. Also we switched from a hard bottom paint to a hybrid ablative the same year we got the folding prop, and I suspect the ablative might be a little slower than the original. So I don’t know if the trend lines are exactly an even comparison, but I think on balance they’re a good indicator of the value.
This may be what I'm remembering. I don't recall you stating the higher speed may be due to turbulence. It would be very interesting to see a similar study across more boats.
I find it difficult to see that the Max Prop would give me a lot of better reverse power than my current fixed blade.
Here are two photos I took after docking down in Charleston. We came into Charleston Harbor and went up to the marina near the Charleston Yacht Club. they have this huge long dock, I think they call it the mile long dock or something like that. In any case we were coming in late, we'd had a long leg to get there - we'd left from the Bahamas. It was pretty late like 1, 2 in the morning thereabouts and the entire dock was full except for this one spot. It was tight. I had wind blowing me away from the dock and current that wasn't helping me. I had one crew with me - it would have been really hard to do this one solo and would have more than likely just anchored out even though tiredness was high... I took these two photos the next morning just before we moved the boat back just a bit to center it in the space. In the one photo, you can see there is about 2 feet between my bow sprit and the bow sprit of the boat forward of mine and about 5 or 6 feet between my aft solar panel and the bow of the boat to my stern. The boat on my stern was a trawler and was about 15 feet wide so I couldn't get very close to the dock coming in due to how wide that boat was. I had to come in fairly hot due to the wind and currents. I swung the bow in as close to the dock as I could and then spun the rudder and hit reverse swinging the stern in and stopping the boat dead - in this position. My crew mate stepped off the boat, tied my spring before we got blown back off of the dock. then we just tied her down.
Somebody is going to have to make one heck of a case for any prop that can out perform this fixed blade. Jus' sayin'
dj
As to being able to to maneuver in tight quarters, I was sailing into Sunbay Marina on the East Coast of Puerto Rico. We needed water. They assigned me a slip that was about 3/4's of the way down one of the aisles (what are these called?). The wind was blowing pretty well and as I swung into the slip, my bow thruster quit (that's a long story). I had to quickly back up to not hit the dock and there I was sideways in the aisle. My boat with bow sprit and aft platform and solar panel must be about 50 feet. I don't think that aisle was much more than 60 feet wide with all the boats sticking out into it. The wind was blowing me sideways down the aisle as it took me a minute to remember how to spin my boat around without a bow thruster - one gets lazy.... By the time I was back in the proper mind, I was well past the slip I needed to enter so I had to spin my boat around to head back up and then into my slip. It was actually easier to get into the slip from that direction given the wind direction. All this to say, I can pretty much spin my boat 360 degrees with almost no forward or aft movement - without a bow thruster.
I'm not trying to beat a dead horse here, but everyone keeps saying how great the Max Prop is - If you're not racing, I just don't see the advantage.
Of course, its up to the OP what they want to do...
dj
There are 2 reasons the Max Prop performs better in reverse than other props, blade shape and pitch. Most props, fixed and folding, have blade shapes that are optimized for forward thrust, Max Prop blades are flat, thrust from the blade is the same in forward and reverse. Likewise the blade pitch is the same in forward and reverse, again, the pitch of other props is optimized for forward thrust at the expense of reverse thrust.
Max Prop claims there is about a 4% loss of efficiency in forward compared to folding or fixed props, which translates to about a quarter knot at 7 knots. Because the blades are flat and fairly thin there is less drag when sailing compared to folding props and fixed blade props. As with most things on a sailboat, there are compromises to be made. Better reverse thrust and less drag under sail at the slight expense of speed under power suits me, others may find this unacceptable.
Two other factors that should be mentioned, maintenance and adjustability. Maintenance is a trivial matter. It takes about 10 minutes to grease the prop once a year, that includes the time to dig out the grease and grease gun, grease the prop, and put everything away. The prop pitch can be fine tuned to the individual boat to optimize performance under power. An experienced diver can do this underwater or more easily when the boat is hauled. With experience this can be done in about 20 minutes on land. I've done it 3 times.
The long dock at Charleston is the Mega Yacht Dock and they like to pack the boats in there! For those who haven't been there, the marina is huge. The last time I was there it was a quarter mile from my boat to the showers, one way and I wasn't the furthest away from the showers. The staff use golf carts to get around.
No, it increases prop walk, which is a good thing once you learn how to use it. This allows you to swing the stern or bow without moving forward, sort of like a poor man's bow or stern thruster. Doing a 180° back and fill maneuver is really easy because of the increased prop walk. Backing out of a slip does require a deft touch with the throttle. Several small bursts of power are required rather than continuous power until there is enough sternway to get the rudder working.
Is it worth $3K, that's a personal issue. If it is a choice between a new main or a Max Prop, I'd probably take the new main.
I have never had much prop walk on Tally Ho, but with my 3-blade Max Prop, I can get the boat moving in reverse so much faster, I can steer in reverse so much easier.
Does the 1/2 knot extra speed and best-in-class reverse thrust justify $3k investment? I decided it did. But I realize I “treated myself” when I upgraded from my old 2-blade fixed prop.
I had already bought new sails, so this was next on the list.
Greg
I'm very aware of the Max prop and how it functions. I looked at it closely thinking it may be something I may want for my boat. However, I have a policy that I don't change anything on a new-to-me boat until I sail it for a time period while I get familiar with what things appear that I really want/need to change/upgrade.
After running with my current fixed blade prop, I can't see any reason to improve it. I can stop it on a dime, so to speak, I can spin the boat 360 degrees without a problem, I can back up well enough - now straight line backing could be improved but it's manageable.
However, getting a 4% hit on forward efficiency is not what I need at all. I want to have maximum forward efficiency. If I'm running a passage and need to motor, I'm not going in reverse. I need as much range as I can get. The more efficient my prop and engine are in forward is critical to how I sail. I'm pushing a 20,000lb + boat (no idea how heavy it is loaded) and getting fuel efficiencies between 0.4 gal/hr and 0.75 gal/hr depending upon sea state and how hard I'm pushing. Now if you can improve that I'm interested, but at least it better not take a hit. With a 4% hit from the Max Prop - it is totally off the table for me. If I ever have to re-prop I would consider a campbell sailor..
What we haven't talked about here is price. How much does the Max prop cost compared to an equivalent fixed blade? When I looked at them the cost was high, don't recall the exact number.
dj