Folding props
- Thread starter DanielW
- Start date
Randy Rutledge
Sustaining Member
I have a Flexofold two blade folder on my E 29 and I like the thrust improvement over the fixed two blade prop forward and reverse. The ads promise the moon and more and I feel it lives up to all promises.
There have been a couple of people who said they had more vibration with the folder but I have not had any vibration problems.
Faster and better rudder response
I have finished first at the Dauphin Island race for the past two years and credit mostly to the Flexofold and its low drag ( I did not go for the racing folder , more money and less thrust) . Moving from a close second in the 18 NM race to finishing first about half and hour ahead of the second place finishers with only the prop change to the boat last year and again first by half an hour again.
Would I spend $1000 again for a folder? YES
Would I buy Flexofold again? YES
There have been a couple of people who said they had more vibration with the folder but I have not had any vibration problems.
Faster and better rudder response
I have finished first at the Dauphin Island race for the past two years and credit mostly to the Flexofold and its low drag ( I did not go for the racing folder , more money and less thrust) . Moving from a close second in the 18 NM race to finishing first about half and hour ahead of the second place finishers with only the prop change to the boat last year and again first by half an hour again.
Would I spend $1000 again for a folder? YES
Would I buy Flexofold again? YES
windjunkee
Member III
I tried a Gori 2 blade folder but the gears in it made the whole system too long. When it folded up, the blades hit the rudder. I ended up going with a Max Prop 2 blade feathering prop. The performance difference in light air is amazing. I'd say we gain 1/2 knot at least. The performance difference in all air, on all points of sail is noticeable. We put it on and won the next two races and have been very competitive ever since. With the feathering prop, as opposed to folding, the backing is impressive. We don't get prop walk any more. It backs clean and straight. Its one of the best modifications we've done to VOR.
The downside is that a feathering prop is expensive. I don't recall exactly how much we spent but I'm pretty sure it was over $1200.00.
Jim McCone
Voice of Reason, E-32-2 Hull #134
Redondo Beach, CA
The downside is that a feathering prop is expensive. I don't recall exactly how much we spent but I'm pretty sure it was over $1200.00.
Jim McCone
Voice of Reason, E-32-2 Hull #134
Redondo Beach, CA
tripper_dave
Member II
Martec
When we purchased our 30-2 this past winter it had a fixed 2-blade. I contacted Martec and ordered a 2-blade folding (got a very good price as it was off-season). They fit the prop to my boat and engine (Yanmar YSM 12). It was a breeze to install and has performed flawlessly.
I would highly recommend them.
When we purchased our 30-2 this past winter it had a fixed 2-blade. I contacted Martec and ordered a 2-blade folding (got a very good price as it was off-season). They fit the prop to my boat and engine (Yanmar YSM 12). It was a breeze to install and has performed flawlessly.
I would highly recommend them.
Randy Rutledge
Sustaining Member
Dave,
Is your Martec prop geared?
Is your Martec prop geared?
tripper_dave
Member II
The blades articulate independently.
Randy, you have no hope for success in politics.
Randy Rutledge
Sustaining Member
Pokey
You have to sail well to get the best out of your boat but there comes a time you have to just buy some extra speed and Flexofold provided that. No political aspirations I like retirement.
You have to sail well to get the best out of your boat but there comes a time you have to just buy some extra speed and Flexofold provided that. No political aspirations I like retirement.
Bob Brigham
Member II
I have an E 28 with a folding Martec prop...it may be fine for racing, but it is a nightmare for driving under power. Given the standard Universal engine in the E 28-the M -12--is way underpowered at 10hp, adding a folding prop is double jeopardy. Hard to make way in a strong current and impossible in reverse in almost any condition. I would spend the money and get the Max Prop...
tripper_dave
Member II
Intriguing, I have had no problems with power, the Martec supplied prop is way better in reverse than I experienced in my last boat (Catalina 27 with Atomic 4 and fixed 2-blade prop. I did a fair amount of motoring this summer including some pretty hard stuff through waves directly into significant headwinds and found that there was enough power to push he boat through. Recently motored back from a regatta into a 10 knot breeze with 1/2 meter swells at 6.25 knots. I think the 30-2 is heavier than the 28, perhaps your prop is the wrong size or pitch?
Bob Brigham
Member II
What size is your engine? Using the standard 2 hp for every thousand pounds of displacement, the E 28 is underpowered by 5 hp. Prop is correct size and pitch...just cannot handle the 3 k current we have on the Hudson...finally changing out this winter
tripper_dave
Member II
Engine is a Yanmar YSM 12. It's 12 HP. I've always understood the formula as 2-3 HP per Ton, not per 1000.
A 30-2 is about 5 tons, so at 12 HP we're in the low-end of normal.
The "black art" of prop selection
We have been through two fixed two blade props, one feathering two blade, and currently a fixed three blade prop, since we bought our boat in '94. The pitch was really wrong on the two blade fixed that it came with, and probably had been that way for years.
Assumptions about the correctness of the prop on your boat when you bought it, new or used, and often unwarranted.....
Our current three bladed fixed is almost (but not quite...) perfect, and good enough for us.
For many years I thought that boats like mine would motor at about 6 to 6.5 kts. Now I know better! We routinely motor at 7. kts. While we gave up some real speed under sail for this "cruising" prop, the journey has been worthwhile to arrive at the point where we know what pitch (and number and shape of blades) really matches our hull and motor.
FWIW, a YSM-12 is a real work horse of a diesel. I have done a week-long delivery on a 33 foot sailboat with that same engine and it puts out enough torque for that boat to motor 24/7 at 6 Kt +.
There are some good threads here on prop choices. Some searching might be in order.
http://www.ericsonyachts.org/infoexchange/showthread.php?571-quot-Prop-Options-quot&referrerid=28
http://www.ericsonyachts.org/infoex...?7999-Prop-Comparisons-part-two&referrerid=28
Not an all-inclusive list, by far, but a start.
Cheers,
Loren
We have been through two fixed two blade props, one feathering two blade, and currently a fixed three blade prop, since we bought our boat in '94. The pitch was really wrong on the two blade fixed that it came with, and probably had been that way for years.
Assumptions about the correctness of the prop on your boat when you bought it, new or used, and often unwarranted.....
Our current three bladed fixed is almost (but not quite...) perfect, and good enough for us.
For many years I thought that boats like mine would motor at about 6 to 6.5 kts. Now I know better! We routinely motor at 7. kts. While we gave up some real speed under sail for this "cruising" prop, the journey has been worthwhile to arrive at the point where we know what pitch (and number and shape of blades) really matches our hull and motor.
FWIW, a YSM-12 is a real work horse of a diesel. I have done a week-long delivery on a 33 foot sailboat with that same engine and it puts out enough torque for that boat to motor 24/7 at 6 Kt +.
There are some good threads here on prop choices. Some searching might be in order.
http://www.ericsonyachts.org/infoexchange/showthread.php?571-quot-Prop-Options-quot&referrerid=28
http://www.ericsonyachts.org/infoex...?7999-Prop-Comparisons-part-two&referrerid=28
Not an all-inclusive list, by far, but a start.
Cheers,
Loren
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Grizz
Grizz
Martec Eliptek Proponent
Won't know the Diameter or the Pitch for 2-3 weeks, which is disappointing, 'cuz that'll mean the boat's been hauled for her winter slumber. But she'll cruise in flat to small waves (3' and less) all day @ 7 knots w/o running north of the rpm 'sweet spot', this with a Universal 25-XP, or is it a 25-PX? So confusing. Either way, it's the 3 cylinder and Martek asked a lot of questions about hull, displacement, engine and shaft-to-hull clearance before we settled on this diameter and pitch. I believe they got it right in this one.
Won't know the Diameter or the Pitch for 2-3 weeks, which is disappointing, 'cuz that'll mean the boat's been hauled for her winter slumber. But she'll cruise in flat to small waves (3' and less) all day @ 7 knots w/o running north of the rpm 'sweet spot', this with a Universal 25-XP, or is it a 25-PX? So confusing. Either way, it's the 3 cylinder and Martek asked a lot of questions about hull, displacement, engine and shaft-to-hull clearance before we settled on this diameter and pitch. I believe they got it right in this one.
DanielW
E-28 Owner
My E-28 has a Volvo Penta 2002, at 18HP I think this is just right for the 28, I've never felt under-powered.
I have a 1990 e28 with a folding prop there are no gears in the prop. I don't have basis for comparison but I was planing to switch back to the standard prop which also came with the boat because I have found the boat reverses poorly and I think i should be getting a bit more forward thrust as well. Probably not the most experienced feedback you'll receive but figured i'd throw in my two cents. Maybe its just the Universal m12 that is under powered for this boat. Live in Chicago now but I use to sail the Hudson River, kept a Catalina 22 in Kingston NY. I started with a 9.9 sailmaster switched to a new 4 stroke honda 8 my last year. When Tide and current were working together I always wished i had purchased a larger replacement. Its a lot of work bucking tide and river! would be interested to know what you decide. Good luck !
Special K
Member II
replacing prop on E28
I have purchased a Flex-o-fold two blade 12 x 9 for my E28. I am waiting to have it installed as we speak (or should I say type). I formerly had a two blade Michigan 12 x 7. My prop guy had the Michigan repitched to 12 x 10 to "test" the pitch. I must say that the power and speed difference with the re-pitching has been amazing, although 12 x 10 may be too aggressive (produced some soot on the transom). Speed is up from 4 knots to a very easy 5.5+ without pushing the rpm (remember the soot).
I was looking at the Flex-o-fold yesterday and it truly is a work of art. The folding nature of the blades allows for a greater area for each blade without the increased drag that would be present in a fixed blade. I am really hoping that this additional surface area will translate into additional power when dealing with head seas. I have already noticed that simply repitching the old prop has dramatically increased the apparent power in such situations. I will be glad to share my experiences with you as I move forward.
I have purchased a Flex-o-fold two blade 12 x 9 for my E28. I am waiting to have it installed as we speak (or should I say type). I formerly had a two blade Michigan 12 x 7. My prop guy had the Michigan repitched to 12 x 10 to "test" the pitch. I must say that the power and speed difference with the re-pitching has been amazing, although 12 x 10 may be too aggressive (produced some soot on the transom). Speed is up from 4 knots to a very easy 5.5+ without pushing the rpm (remember the soot).
I was looking at the Flex-o-fold yesterday and it truly is a work of art. The folding nature of the blades allows for a greater area for each blade without the increased drag that would be present in a fixed blade. I am really hoping that this additional surface area will translate into additional power when dealing with head seas. I have already noticed that simply repitching the old prop has dramatically increased the apparent power in such situations. I will be glad to share my experiences with you as I move forward.
beachologist
Member I
Love my martec elliptical folding prop!! Tried a 3 fixed for awhile, hated the noise when free wheeling and the drag cost me at least 0.5 knots if not more. I have plenty of forward thrust and only seldom use reverse.
Bob Brigham
Member II
DanielW,My E 28 has the Universal M -12, 10 hp! Would love the extra horses of your Volvo engine. Any E 28 owners tried the Gori two blade prop? I know that there have been fit problems on other boats. I am finding that many prop manufacturers cannot recommend their props for boats under 15 hp...Gori can go down to 10 hp, but it it doesn't fit...Cheers, Bob