CLP
Well-Known Member
Has anyone any experience of Kiwi feathering propellors? The recent write-up in YM was positive and the information on their web site sounds convincing too.
Feathering Propellors
- Thread starter CLP
- Start date
sailorman
Well-Known Member
kds
Well-Known Member
Check out Darglow.
Ken
Ken
FullCircle
Well-Known Member
They are absolute rubbish. Never buy something you havent done a search on. Mine is going in the bin. I wish I'd done a search on its effectiveness on here before I bought one. So expensive, and dont work at all in forward or reverse. Blades are a different material to the rest of it, never knew that, as I hadnt really looked at the history of the things here. Rubbish design by some foreign mob, and represented by a non caring lot here, I think. Dunno tho.
I think that the message here maybe that if you go to the search and type in Kiwiprop and extend the date out to 1 year, you may find a wealth of practical info, and, on this subject, fairly data driven.
I think that the message here maybe that if you go to the search and type in Kiwiprop and extend the date out to 1 year, you may find a wealth of practical info, and, on this subject, fairly data driven.
thalassa
Well-Known Member
Re: Fullcircle. Jim, this is a 180degree change of heart. What happened? Or was this tongue-in cheek?
My KIWI -installed in April- performed reasonably well, but I had one of a batch made last winter, when they redesigned a bearing (bronze >SS), causing the reverse to jam after a few months. Not every prop developed this, but seeing the mails I've got, more often than the dealer led me to believe. Prop is now back to the dealer, who will repitch the blades too.
My KIWI -installed in April- performed reasonably well, but I had one of a batch made last winter, when they redesigned a bearing (bronze >SS), causing the reverse to jam after a few months. Not every prop developed this, but seeing the mails I've got, more often than the dealer led me to believe. Prop is now back to the dealer, who will repitch the blades too.
TiggerToo
Well-Known Member
Kiwi on ours, no problems so far! Fingers x-ssed!
ricknesham
New Member
I can only speak as I find, which in my case is that I fitted a Kiwi at the beginning of the season to a 34' fin keel, spade rudder sloop. It replaced a two blade folding Volvo. The results, for me, were spectacular. I now get 6.25 kts at 2000 rpm (in forward - haven't tried maximum speed in reverse!). Beforehand I was achieving 5.5 kts. Naturally, changing from two blades to three should improve performance, but given I have gained little or nothing in drag, I consider that hugely beneficial. Reverse is now more or less instant and apparently completely free of prop walk, which was very pronounced with the VP folder. However, one of the biggest benefits is that you obtain excellent drive at tick over speeds as you don't have to spin the prop fast to unfold the blades. It makes manouevring in marinas a calm and controlled event. I have no problem with "plastic" blades - they may even deflect where more rigid material break should they strike flotsam. They can be replaced very quickly with the boat still afloat - though I believe the manufacturers claim only 16 have been replaced worldwide. The product appears sound, so maybe FullCircle's problems lie in the set up? I found the UK agents very helpful. Perhaps their advice should be sought.
davidbains
Well-Known Member
I also don't know what Full circle is talking about.
In fact he may be joking rather poorly.
Fitted a Kiwi prop this season and am very impressed with it.
As others have said the reverse is amazing, so powerful and instantaneous, and strangely almost no propwalk.
Forward speed has been increased slightly but there is definitely more power available while manoevring.
Sailing especially in light airs is significantly improved. There may be some additional advantage due to the Kiwi prop feeding the rudder clean water.
It's main advantage over other designs is that the blades align with water flow rather than the shaft, means much less drag. I'm sure the Delrin blades are strong enough although I paid for a spare "just in case". After all if you hit something with a metal blade youve still got problems, and will have to haul, whereas a Delrin blade can be replaced underwater if nec.
It's important to liase with Vectamarine, who are very helpful, to establish correct size. And after trials there is scope to easily adjust the pitch to the power available.
In fact he may be joking rather poorly.
Fitted a Kiwi prop this season and am very impressed with it.
As others have said the reverse is amazing, so powerful and instantaneous, and strangely almost no propwalk.
Forward speed has been increased slightly but there is definitely more power available while manoevring.
Sailing especially in light airs is significantly improved. There may be some additional advantage due to the Kiwi prop feeding the rudder clean water.
It's main advantage over other designs is that the blades align with water flow rather than the shaft, means much less drag. I'm sure the Delrin blades are strong enough although I paid for a spare "just in case". After all if you hit something with a metal blade youve still got problems, and will have to haul, whereas a Delrin blade can be replaced underwater if nec.
It's important to liase with Vectamarine, who are very helpful, to establish correct size. And after trials there is scope to easily adjust the pitch to the power available.
theotter
Well-Known Member
I fitted a KiwiProp to my new D1-30 and saildrive at the begining of the season. I completely agree with everything said by Salty Pork
DaveS
Well-Known Member
I think you'll find that FullCircle is extracting the urine, and that he's also a Kiwi fan - as am I. The point being that it's a subject aired on quite a few earlier threads which a search should reveal.
On a related topic: I'm about to take my boat out after my first successful season with a Kiwiprop. I'm thinking about reducing the forward pitch a little to give me (a) lower tickover speed, and (b) higher engine revs to reach full speed. On the latter, I can currently only reach 2500 in forward gear and the engine spec (VP2002) says 3200 - which it easily does in neutral. So my reasoning is that the prop is still a bit too course.
On an earlier discussion the interesting point was made (but not, IIRC, picked up by anyone,) that there are different traditions in different parts of the world, with some seeking to do as I propose, i.e. try to hit max power at rated full engine speed; while others prefer max power at a significantly lower speed.
I'm interested in the arguments pro and con. Any views?
On a related topic: I'm about to take my boat out after my first successful season with a Kiwiprop. I'm thinking about reducing the forward pitch a little to give me (a) lower tickover speed, and (b) higher engine revs to reach full speed. On the latter, I can currently only reach 2500 in forward gear and the engine spec (VP2002) says 3200 - which it easily does in neutral. So my reasoning is that the prop is still a bit too course.
On an earlier discussion the interesting point was made (but not, IIRC, picked up by anyone,) that there are different traditions in different parts of the world, with some seeking to do as I propose, i.e. try to hit max power at rated full engine speed; while others prefer max power at a significantly lower speed.
I'm interested in the arguments pro and con. Any views?
Georgio
Well-Known Member
I can't comment on the Kiwi, but I have a Darglow three plade feathering prop and it's great. /forums/images/graemlins/smile.gif
cindersailor
Well-Known Member
I think the point here is that an engine only produces full power at full revs. If you are only reaching 2500 then you are not making use of the full power of your engine because it is overproped. Take a look at the RPM/HP curve for any engine and this becomes clear. Consequently if you reduce the pitch you should be able to get more power into the water because the engine can get up to higher revs where it produces more power. It seems to me that this is one of the benefits of the Kiwiprop, pitch can be adjusted to suit the engine/boat without sending it of to a machine shop.
thalassa
Well-Known Member
It was my dealer which told me about the pitch settings on the KIWI. He told me that, if the manufacturer has no reference of, or prior experience with, a particular setup (make of boat-engine), they set the KIWI so hull speed is reached at maximum allowable RPM. He maintains that in Holland, and most other European countries, it is common practice to choose a pitch so that hull speed is reached at lower RPM's, typically 2200-2400 engine RPM's.
I agree fully that it is a very capable prop for harbour manoevering. As said, great stopping power near tickover. Slightly lackluster starting forward. On my setup, propwalk was however stronger than on the old "duckbill ". I've let her dry out twice on hard sand, no problems with the "plastic" blades!
The article in YM was a bit of a disappointment. Mostly a paraphrase of the manufacurer's website.
I agree fully that it is a very capable prop for harbour manoevering. As said, great stopping power near tickover. Slightly lackluster starting forward. On my setup, propwalk was however stronger than on the old "duckbill ". I've let her dry out twice on hard sand, no problems with the "plastic" blades!
The article in YM was a bit of a disappointment. Mostly a paraphrase of the manufacurer's website.
DaveS
Well-Known Member
Yes, that's the line of reasoning I'm coming from, and why I'm thinking of dropping the pitch a bit. Isn't it good to have it adjustable? /forums/images/graemlins/smile.gif It does mean maintaining higher revs for a given boat speed, but I wasn't thinking that would be a problem.
OTOH is it just a regional fashion thing to opt for courser pitching which restricts max revs, or are there any actual advantages?
OTOH is it just a regional fashion thing to opt for courser pitching which restricts max revs, or are there any actual advantages?
FullCircle
Well-Known Member
Only kidding! /forums/images/graemlins/grin.gif
Do the search.
Just dealing with Vectamarine is reward enough when it comes to knowing what customer service is.
Very pleased to know that I confused a few of the Dear Readers, at least for a while. Those who have been reading my reports for a while will know how much I put into it.
Do the search.
Just dealing with Vectamarine is reward enough when it comes to knowing what customer service is.
Very pleased to know that I confused a few of the Dear Readers, at least for a while. Those who have been reading my reports for a while will know how much I put into it.
kengill
Well-Known Member
I wouldn't bother with them. True they feather but a folding prop folds out of the way and gives less drag than a featherer and also does not leave the blades out in the water stream to foul any passing rope or driftwood.
Just one point I have a 31"10" boat which has a folding prop and I can maintain 7.2 knots going forward at 3500 RPM. The folding prop has increased my average speed by about 1/2 a knot
PS folders are also cheaper!!
There again you pays your money an takes your pick.
Just one point I have a 31"10" boat which has a folding prop and I can maintain 7.2 knots going forward at 3500 RPM. The folding prop has increased my average speed by about 1/2 a knot
PS folders are also cheaper!!
There again you pays your money an takes your pick.
DaveS
Well-Known Member
And folding props usually open up OK when you put on the power...
doug748
Well-Known Member
Do you have the Beta 20hp as well? I am thinking of upgrading to this engine plus Darglow on the Contessa. I will be fitting it myself, if I go ahead, any tips? Do you have the size, part no and rough cost of the prop? thanks Brian.
sailorman
Well-Known Member
have it slightly " over-pitched" for when you might motor-sail
CLP
Well-Known Member
A lot of helpful info here, thanks everyone, although I was a bit alarmed by fullcircle's answer. Anyway I've got a Contessa 32 and I'm not sure yet if there is enough aperture size to fit a Kiwi. Most other Co32 people seem to fit Darglows. I want decent speed/power ahead into a lumpy sea and I want good reverse and limited drag when sailing - probably all too much to ask.
