Max Prop Performance

[Edward English]

We installed a 3 blade "classic" max prop on our new Ben 40 and have noticed significant prop walk to port in reverse. I had understood that the prop walk  in reverse was minimal. What is your experience. If it is normally minimal, any thoughts on what could be the issue? 

Thanks for your comments.

Ed

Orange Blossom Special

[B311 Incorrigible]

On our B311 we changed from a 2 blade fixed to the 3 blade max prop
and did find noticeable increase in prop walk. I just attributed
it to additional surface area.

Not sure if others had different experiences?

Roger
B311 Incorrigible

[gking...@gmail.com]

Have had similar experience when switched out fixed 3 blade for Kiwi prop on my B411, but performance under sail well worth the inconvenience. Close to 1knot.
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[Larry Cost]

We have three blade max prop on our 473. Boat backs very well. If I try to reverse hard with forward motion, I do have prop walk. I just start slow and very quickly can back up with no prop walk at all.   Larry s/v TraSea Beneteau 473 #25 --- On Tue, 9/14/10, Edward English <ejsa...@gmail.com> wrote:

[Ben Campbell]

Hi,

I've also been considering putting a MaxProp on my Beneteau 31. It currently backs pretty well with the OEM 3 blade fixed prop. I recognize the value of the MaxProp when sailing, but am I likely to see a big increase of prop walk? I was under the impression that good reverse behavior was one of their advertised features.

Thanks!

Ben.

[Brian Smith]

I've got an autoprop, and have very little prop-walk.  Much less than I had with a two-blade fixed prop on my Catalina 30.

Never motored a 381 with a different prop, so I can;t compare directly.

Brian

__________________

 Oc381 LiWei

Annapolis

[Mark J Wilme.]

Talking of props and prop shafts - does anyone know if the prop shaft will pull on a 381 without dropping the rudder?

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From: Brian Smith <Li...@StargazerSystems.com>

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Date: Tue, 14 Sep 2010 11:09:30 -0400

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ReplyTo: benetea...@googlegroups.com

Subject: Re: {Beneteau Owners} Max Prop Performance

[Matt Lynch]

I've had a B351 with a 3-blade fixed OEM prop, a 3-blade Gori folding/feathering and now a 3-blade Max.   I can say that in my experience I had the most prop walk by far with the 3-blade fixed.  The sailing speed increase with either Max or Gori approaches a full knot.  Between the Max & Gori, I feel there is a little more walk with the Max, maybe a little less power and maybe a little less fuel efficiency.    The trouble I ran into with Gori was that a blade came off for no apparent reason and because of the way they do business, they really could only offer to sell me a new prop.  Apparently, the prop has to be shipped overseas to be remanufactured and dynamically balanced and when all that shipping is added up plus a new blade *poof* you are magically at the cost of a new prop.  Real or not that was the story I got.  My friend sent back a 15 year-old Max and got it reconditioned like new for $150.  So, with my original investment lost, I decided to switch to Max and I'm happy with them.  I don't really notice the comparative weaknesses I've hesitantly listed above.    --- On Tue, 9/14/10, Ben Campbell <b...@nostrum.com> wrote:

[David Mackintosh]

Does no one have the KiWi prop?

http://www.kiwiprops.co.nz/

I am thinking hard about getting one to make the boat a little faster under sail

But then i am also thinking about a shaft driven alternator/generator so that makes a folding/feathering prop a no go - though i am told that the Gori overdrive prop can also work in a regenerative mode.

regards

David

[David Mackintosh]

Just remembered you can use a max prop in regeneration mode - if you leave it in reverse 'i think' it wont feather it stays open.

regards

David

[David Fletcher]

I have a Kiwi prop on a Beneteau OC400. I put it on before I launched the boat as the second owner, I am happy with it however I do not know anything but it.

 

Certainly the most prop for the money.

 

Fletch

 

---

[Matt Lynch]

Normally, you kill the engine in forward and that feathers the prop.  Sometimes you may have the prop still spinning and need to put it in reverse *after* you are sailing.    IF you kill the engine in reverse, the prop won't feather and then you can use it to drive a shaft alternator. --- On Tue, 9/14/10, David Mackintosh <sv.highl...@gmail.com> wrote:

[jpmcla...@rcn.com]

I initially replaced my 3-blade fixed OEM prop with a 3-blade Gori folding/feathering and now a 3-blade Max as well. Gori was a better performing prop but caused a lot of vibration and had to get rid of it. Customer Service was terrible as well. Took z months for them to finally accept the return of a new prop.

I now love my Max Prop. There is still prop walk but I always thought that was helpful and I do not know what I'd do without it. Can't go wrong with a Max Prop. Power in reverse is good but nothing unusual.

Fact is everyone loves the folding/feathering prop they have chosen (assume no mechanical issues). Max is great but the others are as well. I suggest research, price and pick one.

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From: Ben Campbell <b...@nostrum.com>

Sender: benetea...@googlegroups.com

Date: Tue, 14 Sep 2010 10:05:49 -0500

To: <benetea...@googlegroups.com>

ReplyTo: benetea...@googlegroups.com

Subject: Re: {Beneteau Owners} Max Prop Performance

[jpmcla...@rcn.com]

I initially replaced my 3-blade fixed OEM prop with a 3-blade Gori folding/feathering and now a 3-blade Max as well (on a 393). Gori was a better performing prop but caused a lot of vibration and had to get rid of it. Customer Service was terrible as well. Took z months for them to finally accept the return of a new prop.

I now love my Max Prop. There is still prop walk but I always thought that was helpful and I do not know what I'd do without it. Can't go wrong with a Max Prop. Power in reverse is good but nothing unusual.

Fact is everyone loves the folding/feathering prop they have chosen (assume no mechanical issues). Max is great but the others are as well. I suggest research, price and pick one.

------Original Message------
From: Ben Campbell
Sender: benetea...@googlegroups.com
To: benetea...@googlegroups.com
ReplyTo: benetea...@googlegroups.com
Subject: Re: {Beneteau Owners} Max Prop Performance
Sent: Sep 14, 2010 11:05

Hi, I've also been considering putting a MaxProp on my Beneteau 31. It currently backs pretty well with the OEM 3 blade fixed prop. I recognize the value of the MaxProp when sailing, but am I likely to see a big increase of prop walk? I was under the impression that good reverse behavior was one of their advertised features. Thanks! Ben. On Sep 14, 2010, at 9:42 AM, Larry Cost wrote: We have three blade max prop on our 473. Boat backs very well. If I try to reverse hard with forward motion, I do have prop walk. I just start slow and very quickly can back up with no prop walk at all.   Larry s/v TraSea Beneteau 473 #25 --- On Tue, 9/14/10, Edward English <ejsa...@gmail.com> wrote: From: Edward English <ejsa...@gmail.com> Subject: {Beneteau Owners} Max Prop Performance To: "Beneteau-Owners" <Benetea...@googlegroups.com> Date: Tuesday, September 14, 2010, 2:05 AM We installed a 3 blade "classic" max prop on our new Ben 40 and have noticed significant prop walk to port in reverse. I had understood that the prop walk  in reverse was minimal. What is your experience. If it is normally minimal, any thoughts on what could be the issue?  Thanks for your comments. Ed Orange Blossom Special -- Largest Beneteau group, over **900** members and growing. Read these list rules in the groups pages, cut and paste this link http://groups.google.com/group/beneteau-owners/web/LIST+RULES?hl=en To post to this group, send email to Benetea...@googlegroups.com To unsubscribe from this group, send email to Beneteau-Owne...@googlegroups.com For more options, visit this group at http://groups.google.com/group/Beneteau-Owners contact denny.we...@gmail.com, or ume...@comcast.net if you have a list management question -- Largest Beneteau group, over **900** members and growing. Read these list rules in the groups pages, cut and paste this link http://groups.google.com/group/beneteau-owners/web/LIST+RULES?hl=en To post to this group, send email to Benetea...@googlegroups.com To unsubscribe from this group, send

[Ivars]

prop walk is driver induced... it is a "physics thing"...  it's up to you how much prop walk to get

 

just go for it and get rid of the fixed prop...your entire boating experience will be enhanced...especially under sail

 

Max Prop is a good choice...They all work well and infinitely superior to a fixed blade prop... unless you plan on doing 100% morotring with your boat  :=)

 

 

---

From: benetea...@googlegroups.com [mailto:benetea...@googlegroups.com] On Behalf Of Ben Campbell
Sent: Tuesday, September 14, 2010 11:06 AM
To: benetea...@googlegroups.com
Subject: Re: {Beneteau Owners} Max Prop Performance

[gking...@gmail.com]

I have a Kiwiprop fitted to my B411. Very happy so far, close to 1knot extra speed under sail, but a little prop walk in reverse that wasn't there with the fixed blade.

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From: David Mackintosh <sv.highl...@gmail.com>

Sender: benetea...@googlegroups.com

Date: Tue, 14 Sep 2010 18:08:25 +0100

To: <benetea...@googlegroups.com>

ReplyTo: benetea...@googlegroups.com

[Rick Donovan]

Ed
as far as I am concerned, you can not totally eliminate prop walk with any prop design that I have used or been around. some are better than others, but they wil all pull one way or the other to some degree. there are occassions where it is a desirable feature, sort of like parallel parking your car.

Rick Donovan
Biddeford, Maine

[Larry Cost]

I agree with Rick. My 473 is side tie port side to the dock. Coming into the dock I use prop walk to swing the stern into the dock. Makes coming along side very easy. As Rick stated earlier. Prop walk is mostly induced by the helmsman. Leaving the dock I use minimal power until i get flow across the rudder and then backing is easy.   Larry s/v TraSea Beneteau 473 #25 --- On Tue, 9/14/10, Rick Donovan <rdono...@maine.rr.com> wrote:

From: Rick Donovan <rdono...@maine.rr.com> Subject: Re: {Beneteau Owners} Max Prop Performance To: benetea...@googlegroups.com

[Jack Vetter]

My max prop walks to starboard in reverse. Weird.
FWIW.

Jack

Jack Vetter
Tutto Bene
Beneteau First 38s5
Sacramento, CA
916-441-4441

-----Original Message-----
From: benetea...@googlegroups.com
[mailto:benetea...@googlegroups.com] On Behalf Of Rick Donovan
Sent: Tuesday, September 14, 2010 2:02 PM
To: benetea...@googlegroups.com
Subject: Re: {Beneteau Owners} Max Prop Performance

Rick Donovan
Biddeford, Maine

--

[Bill Jarvis]

Do you have a Volvo engine? Or some other reason for a lefthanded prop?

Bill

[j...@ouimet.biz]

A year ago the UK Yachting Monthly did a pretty good evaluation of a
bunch of props.
http://www.flexofold.com/upload_dir/docs/Test_YachtingMonthly_low.pdf

They even measure prop walk which, I think, is a first. All of these
measures were static (ie motoring against a fixed attachment point) so
it may or may not represent real life. Test were done with a B323.


As far as prop walk being an operator condition, sometimes design just
does not help! On my B40, there are two steering wheels. The engine
controls are on starboard, so you pretty well have to stand and dock
on that side, but the prop walk is to port. So, when I come in against
the tide, in a shared dock space with not much clearance to the next
guy, I need some headway to keep steerage and get alongside the dock
for the mate to jump off. As soon as I apply some reverse, the boat
pulls away from the dock which invariably leads to a discussion
between the mate and I. If that thing had only been engineered
properly, prop walk would be to starboard to enhance docking, not to
make it more difficult.

Jacques Ouimet
B40 Solander II
Hingham

On Sep 14, 2:05 am, Edward English <ejsai...@gmail.com> wrote:

[David Mackintosh]

Yep me too - on the 461 with the Yanmar engine GREAT Prop Walk to the left (3 bladed fixed prop ATM) so coming into the dock on the port side we approach at a 45 degree angle and then a big burst astern as the bow gets close to the dock and OMG its parallel parking with no forward speed.

As to Prop walk you CANT stop it BUT you CAN use it to advantage as above or negate it by - oh my - is that 'rudder authority thing' again getting the boat moving so the rudder controls your direction not prop walk which is a fact of life and cant be eliminated only overcome and tamed and used in a positive way.

Again it is about learning how to sail your boat - and like Ladies which they all are of course they may all look similar but they have all got quite different idiosyncrasies and  temperaments but putting that aside we do love them and are passionate about them - i am of course speaking about 'The Admirals' now ;-)

regards

David

[David Mackintosh]

Not really Jack - it depends on the rotation of your prop.

regards

David

[Ivars]

...if you look closely on the underside of the transmission there is a lever
that will change the direction of rotation of the prop and shifting prop
walk to starboard... A new prop will be needed... To keep forward from
being backward and backward from being forward :=) :=)

-----Original Message-----
From: benetea...@googlegroups.com
[mailto:benetea...@googlegroups.com] On Behalf Of j...@ouimet.biz
Sent: Tuesday, September 14, 2010 7:58 PM
To: Beneteau Owners
Subject: {Beneteau Owners} Re: Max Prop Performance

--

[Rick Donovan]

On Sep 15, 2010, at 9:40 AM, Ivars wrote:

> ...if you look closely on the underside of the transmission there is a lever
> that will change the direction of rotation of the prop and shifting prop
> walk to starboard... A new prop will be needed... To keep forward from
> being backward and backward from being forward :=) :=)

is this true?? I have never heard of such a thing.
or is Ivar's playing with my head??

Rick Donovan
Biddeford, Maine

[Ivars]

Absolutely not true, couldn't resist messing with all the prop walk BS so I
thought to create some of my own

-----Original Message-----
From: benetea...@googlegroups.com
[mailto:benetea...@googlegroups.com] On Behalf Of Rick Donovan
Sent: Wednesday, September 15, 2010 9:45 AM
To: benetea...@googlegroups.com

Rick Donovan
Biddeford, Maine

--

[Rick Donovan]

On Sep 15, 2010, at 10:34 AM, Ivars wrote:

> Absolutely not true, couldn't resist messing with all the prop walk BS so I
> thought to create some of my own

that is not funny for some of the old guys!! I had never seen anything like it but I have not seen it all, yet, lol.
I thought about the possibility for a while before responding to ask the dumb question whether it was true or not.
I hate looking stupid.

Ivars one, list zero

Rick Donovan
Bideford, Maine

[David Mackintosh]

Interesting bit of Quasi science - why does the max boat speed not match max bollard pull?  Even a wee bit about why it did not would be 'interesting'  Similarly in reverse why does stopping time/distance not match bollard pull?  Also why did they not drag test the boat with the various props on?  Probably because the difference would have been insignificant perhaps immeasurable -  I do wonder if they did and then had to put them on the dinghy to get any 'useful' figures - putting these props on a lightweight dinghy to get drag figures was interesting but hardly relevant.....BUT most silly of all was the suggestion that "prop drag will add about four hours to a typical cross-Channel passage." lets say this Bennie does 6 knots cruising that is another 24 miles and lets say prop drag is worth a knot in boat speed that is like you have been sailing for 24 hours to cross the English channel :-(  Also prop drag is only important - or matters - when you are sailing in lighter winds at under hull speed - once you have ooodles of extra horsepower from your sails you can forget about it.  Also since their static figures did not match the dynamic figures (what a surprise not) surely that makes the prop walk figures equally suspect???

Re the B40 with the R/H/S prop walk  surely it is easier to use the prop walk to help you dock even when you are on the other side of the boat from the dock.  IF being on the wrong side is a problem go fly by wire electronic engine gearbox controls and have them at both helms. 

http://pdf.nauticexpo.com/pdf/vetus/vetus-general-catalogue/21508-16448-_50.html

If the gearbox has the same ratios forwards and astern you could 'maybe' (depends on the gearbox) swap F&R and change the prop for the other hand then make a small adjustment to your morse cable control to swap over forwards and reverse actuation at the gearbox end.

Or for a cheap and easy fix - if this is your home berth use a fixed length spring with a loop in the end - drop that over the dock cleat first - and use that to stop the boat.

regards

David

[Noble, Milner E.]

That's odd... I have a lever located there...
--Milner

-----Original Message-----
From: benetea...@googlegroups.com [mailto:benetea...@googlegroups.com] On Behalf Of Rick Donovan
Sent: Wednesday, September 15, 2010 10:44 AM
To: benetea...@googlegroups.com
Subject: Re: {Beneteau Owners} Re: Max Prop Performance

Ivars one, list zero

Rick Donovan
Bideford, Maine

--

[David Mackintosh]

HO HUM

just read the wee lever post :-(

MY post is accurate - cross my heart and all of that :-) the gearbox dont care which way is forwards or backwards BUT some gearboxes have different Forward and Reverse ratios.

If in doubt ask the gearbox manufacturer.

regards

David

[MagicaTi]

In my 393 a FOF folding prop was fitted as part of the "performance
package".
Very good forward thrust and under sail performance; almost
unmanageable in reverse.
Changed to a Max-Prop 3 blade feathering prop: walk reduced by 2
thirds and absolutly predictable. Forward and sailing performances
seem unaffected.
Cheers

[Guy]

Drag at various speeds... the drag increase exponentially with boat speed... while sailing at 7kts with my 3 blade, the propwash is like I have the motor on.

 

Yes the drag at 2-3 knots, will kill you in a race, but at 6-8 kts, its really a bear.

 

I've raced against a bunch of guys with martec folder and with OEM 3 blade... with 15kts across the deck, close hauled, I can't point as high or as fast with 3 blade vs martec.

 

anecdotal vs measurable, but you know what I'm saying.

-------------------------------------------------
Captain Guy
New Smyrna Beach FL USA
386-689-5088
-------------------------------------------------
s/v Island Time (Beneteau 352#277)
AICW 845.5

----- Original Message -----

From: David Mackintosh

To: benetea...@googlegroups.com

Sent: Wednesday, September 15, 2010 10:44 AM

Subject: Re: {Beneteau Owners} Re: Max Prop Performance

[Guy]

Check the math

 

24 miles at 6 kts = 4 hours

24 miles at 7 kts =  3.4 hours

delta = 0.6 hours or 36 minutes

-------------------------------------------------
Captain Guy
New Smyrna Beach FL USA
386-689-5088
-------------------------------------------------
s/v Island Time (Beneteau 352#277)
AICW 845.5

----- Original Message -----

From: David Mackintosh

To: benetea...@googlegroups.com

Sent: Wednesday, September 15, 2010 10:44 AM

Subject: Re: {Beneteau Owners} Re: Max Prop Performance

[David Mackintosh]

OK here is my maths

We are looking for a 'about' four hour difference in passage time - vis a vis the same boat with a fixed or folding/feathering prop

Forgetting that the English channel is 21 miles wide at its narrowest point -  and that i have sailed from the east end on the English side to the other west end on the French side actually it was Guernsey in 16 hours

Fixed prop to take four more hours on passage than a folding/feathering prop with 'around' a one knot speed advantage to the boat with the F/F prop

Fixed 6 knots  F/F 7 knots

Would be a passage of 'around 160 NM

Fixed takes 26 hours 40 mins

F/F takes 22 hours 52 mins

Around a 4 hour difference

The typical cross channel passage from the Hamble to Cherbourg is around 80 miles - so you will understand why i thought that was just too silly for words.

okidoki

[Guy]

and a trip around the world will take a few weeks longer...

 

you statrted by saying crossing the channel appx 24 miles, now its to gurnesy?

 

whatever... the speed difference is ~15% greater (6 vs 7).

[Rick Donovan]

I have 76HP, and 20" Max Prop..by the way, PYI Inc states that you can also use 19" Max Prop, and I wonder how that changes things.

James

James,

when I was doing my research before buying a feathering prop, I had this same discussion with a couple of sales people. I had been told to use as large a diameter as was recommended by a friend. I decided to try to find out why.

in short, the larger diameter allows the prop to have a slightly less pitch on the blades than the smaller diameter and the end result is that larger diameter should have a bigger "bite" in the water because of that little bit of extra prop blade surface available. the advantages are not real noticeable until it gets a bit snotty on the water. imagine a sea state where you are working the bow into a sea and are climbing up and falling down 3-4 feet or more on each wave. the up down motion of the boat disrupts the bite of the prop some what as the boat moves vertically in the water. that is a scenario where less pitch but a larger diameter is an advantage because it generates a bit more power from the same prop rpm. sort of like a lower gear ratio in a race car helps it to  accelerate quicker. 

however, there are limits to what diameter you can safely swing. there are formulas the pro's use to calculate things like tip clearance and bending forces on the prop shaft itself as well as where the cutlas bearing is in relation to the prop, i.e. how close is that support of the cutlas bearing. the major considerations are the diameter of the prop shaft and the clearance at the blade tip to the hull. if either one of these calculations are wrong, you could end up with some nasty vibrations.

Rick Donovan

Biddeford, Maine

[markd...@hotmail.com]

It is connected to the lever on the bottom of the mast which extends the telescoping upper section and makes the mast 50percent taller when needed. Funny, I never see anyone else use that...

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-----Original Message-----
From: "Ivars" <dbg...@mindspring.com>
Sender: benetea...@googlegroups.com
Date: Wed, 15 Sep 2010 09:40:00
To: <benetea...@googlegroups.com>
Reply-To: benetea...@googlegroups.com
Subject: RE: {Beneteau Owners} Re: Max Prop Performance

....if you look closely on the underside of the transmission there is a lever

[David Mackintosh]

I think you need to go and read carefully what i wrote  i do HATE people miss quoting me i said " that is like you have been sailing for 24 hours to cross the English channel"  

Four hours  the difference in passage time time that they said you would gain or loose depending on your mindset) at 6 knots was 24 miles

regards

David

[David Mackintosh]

does it work the other way for ICW bridges as well?

regards

David

[Daryl Davies]

HI Ed,

I have the 3 blade flex i fold on my Ben 40 and the prop walk is minimal.

Hope your boat is working out. I have found on my 40 that I am continually repairing items.  This is partly due to the fact that I charter this boat out of Long Beach and thus it is getting more use than a normal boat (about 100 days per year), but also I believe that the problems are somewhat related to the fact that my boat was purchased and delivered the first year when Beneteau was selling this model as fast as they could make them -- and thus the quality may have suffered.  This month I had to replace the battery charger.  The old one was suppose to be a Xantrex that was matched with the inverter, but it wasn't as the manufacture had run out during production of the boat.  Now it is a Xantrex that is matched nicely to the inverter, but of course, at my expense.  All in all, a very nice sailing boat, but it has taken me a bit of time to weed out some of the quirks that seemed to slip through the inspection process of the boat.

Daryl

[Jack Vetter]

You are right. It is a Volvo Penta 2003 BT Turbo 27-43Hp

Jack

[Bill Jarvis]

The prop rotates in the opposite direction therefore prop walk is to
starboard not port.

[Mark J Wilme.]

Kinda depends where you cross doesn't it? Its only 21 miles at Dover, it gets a little wider the farther west you go, maybe not 24 hours wider but ...

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---

From: David Mackintosh <sv.highl...@gmail.com>

Sender: benetea...@googlegroups.com

Date: Wed, 15 Sep 2010 17:48:42 +0100

To: <benetea...@googlegroups.com>

ReplyTo: benetea...@googlegroups.com

[David Mackintosh]

yes BUT to have a passage where a one knot speed difference at 6/7 knots makes a four hour difference in passage time you are looking at a 'around' a 160 mile passage

21 miles at 6 knots is 3.5 hours at 7 knots it is 3 hours
21 miles is a 30 min difference
4 hours divide 30 mins equals 8 
21 times 8 equals 168 miles

regards

David