Feathering prop

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Moocher
Moocher
NSW
42 posts
NSW, 42 posts
25 Aug 2014 8:10am
Does anyone have or know anyone that has a Kiwiprop, I've done as much research as possible but it would be great if I could speak to someone that actually has one. The company has a great reputation for after sales issues etc., but I've heard conflicting stories about the prop itself, any feedback would be much appreciated, thanks.
MorningBird
MorningBird
NSW
2711 posts
NSW, 2711 posts
25 Aug 2014 7:06pm
A good mate put one on his S&S34 when he put in a new engine. He isn't happy with it as, despite adjusting the pitch to get the right revs at full power, the boat speed is way below what it should be.
At full power, after an anti foul, I do around 6.8kts, he gets maybe 5.8kts. Engines are similar power, mine shaft drive and his sail drive. My boat is heavier than his by quite a few hundred kgs (I have a wind vane, inner forestay, 300 litres of water (he has 100) and 80 litres of fuel (he has 60), 40kg liferaft).
The kiwi prop pitch is constant from hub to blade tip which reduces its efficiency. Whether this is the problem with his I don't know but he just can't get the best boat speed from it. It goes astern far better than mine.
seabird
seabird
QLD
227 posts
QLD, 227 posts
26 Aug 2014 1:45pm
I looked at the Kiwiprop but decided to go with the Flexifold 3 blade folding prop .
It's been great no loss of performance under motor and noticeable difference when under sail maybe .5-1 kt improvement.
I do have to give it a few more revs in reverse to get it to bite.

When sailing I select reverse which stops it spinning and the water pressure makes it fold, even at slow speed.
HG02
HG02
VIC
5814 posts
VIC, 5814 posts
26 Aug 2014 1:58pm
How long have you had that prop seabird
seabird
seabird
QLD
227 posts
QLD, 227 posts
26 Aug 2014 3:34pm
HG02,
Fitted the folding prop about 4 yeas ago.
When I slip I always check it still folds with growth around it before cleaning, and it does
HG02
HG02
VIC
5814 posts
VIC, 5814 posts
26 Aug 2014 3:58pm
Thanks seabird it's on one of my lists for later on
QLDCruiser
QLDCruiser
QLD
160 posts
QLD, 160 posts
26 Aug 2014 7:34pm
I fitted a Kiwiprop on my S&S34 - with a Bukh DV20 saildrive. It replaced a 3-blade fixed prop, and I was very happy with it. Increased sailing speed by at least half a knot, and a bit better speed under power too (though probably because the old prop was overpitched). From memory, we used to get nearly 7kt under power.

It has a fixed, high pitch in reverse which means it stops the boat very quickly and easily without a lot of revs - but you won't get full revs if you need high power in reverse, eg to back off a grounding.

As MB says, the blades are constant pitch which must detract from their efficiency under power, but does lead to very low drag when sailing. My recommendation would be that if motoring performance is important to you, maybe consider an alternative. But if sailing performance is the main criterion, it would be hard to get better. And when I bought mine, the Kiwi was a lot cheaper than anything else.
MorningBird
MorningBird
NSW
2711 posts
NSW, 2711 posts
26 Aug 2014 7:40pm
I ended up putting a 2 blade Gori folding prop on MB. It works fine. I cruise at 6 or so kts, it folds neatly so sailing performance isn't affected. It won't stop you on a dime but it does stop the boat with a burst of power.
HG02
HG02
VIC
5814 posts
VIC, 5814 posts
26 Aug 2014 8:09pm
MorningBird said..
I ended up putting a 2 blade Gori folding prop on MB. It works fine. I cruise at 6 or so kts, it folds neatly so sailing performance isn't affected. It won't stop you on a dime but it does stop the boat with a burst of power.


How long have you had it fitted MoriningBird? They are a well know folding prop
Just had a peek at the Flexifold 3 blade folding prop looks like a good prop as well
Wonder what the cost difference is between the two
MorningBird
MorningBird
NSW
2711 posts
NSW, 2711 posts
26 Aug 2014 9:42pm
It has been on a couple of years. I had a Gori 15" by 9" which was worn out and under geared. I looked at a range of props but couldn't justify the extra cost above the Gori price, about $1350. I got a 15" by 10" and it is spot on. I get max revs with a clean prop and hull with the boat just below hull speed.
Moocher
Moocher
NSW
42 posts
NSW, 42 posts
27 Aug 2014 7:20pm
Thanks for the feedback, the prop I'm ordering will be a 4bladed feathering, so if anyone needs any info I'm happy to oblige
HG02
HG02
VIC
5814 posts
VIC, 5814 posts
27 Aug 2014 7:42pm
Moocher said...
Thanks for the feedback, the prop I'm ordering will be a 4bladed feathering, so if anyone needs any info I'm happy to oblige

What motor and what horse power?
And yes please more info the better
Thank you
Moocher
Moocher
NSW
42 posts
NSW, 42 posts
27 Aug 2014 9:39pm
Yanmar 4JH3 56hp
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