I’m interested in replacing my 3 blade Campbell propeller on my Nonsuch 33 . It seems not to be able to push the boat well in adverse conditions. It is 14.75 in x 8.5 pitch which I think is not sufficient. Last summer I found myself down to about 1.5 knots into a choppy 20-25 knot wind. That seemed to me to be less capability than what it should be.
I have corresponded with Flex-O-Fold and they recommend either a 2 blade 16 x 12 or 3 blade 15 x 11. I will probably order from that company. Lots of good companies but they seem consistently well thought of.
My question is for those of you who have that brand prop … what size do you have and are you satisfied with the ability to push the boat into wind and chop.
Their original recommendation was 17x12 which was inadequate.
I had them replace the blades with the increased pitch and then it was excellent.
The size they recommended to you seems undersized and underpitched
Thank you Joe. Yes, I provided that data. I did for my last prop and I don’t think the recommendation was right. I’m doing more inquiry this time among those with practical experience.
Rob Bent
NS 33 #17
Solitude
Mallets Bay, Lake Champlain
I’ve been using a two blade 16x11 Flexofold for five seasons. It replaced my two blade fixed prop. I found little to no difference in performance and added speed to my sailing. I did have a major issue though. The installation requires a single set screw (using blue lock tite) to “prevent” the single hub nut from coming loose and backing out. Mine failed. Prop lost. Flexofold sold me a slightly discounted replacement. When we installed the new prop, we drilled out a dimple in the locking nut for the set screw to sit. Also used two shorter set screws on top of one another. Hopefully this prevents another loss.
Good luck
PeterDePascale
Irish Mist
33 #006
Branford CT
Thanks Peter. Your 2 blade is close to what I am being recommended if I went two blade. Have you had the occasion to motor into wind and chop and does the prop drive well enough?
Rob Bent
Solitude
NS 33 # 17
Mallets Bay, Lake Champlain
I had occasion to use a 14x11 fixed prop on my Nonsuch 26 with a W21 engine the summer before last. Comparing the 14x11 fixed blade to the usual 15x11 two blade Gori. The 14x11 is the Hinterholler recommended fixed 3 blade prop and 15x12 for a two blade folding.
The 3 blade was smoother when motoring.
The 3 bladed one did not generate as much power into windy conditions. Maybe half a knot less.
At 2400rom could get 5.1K vs 5.3K with the Gori motoring.
When sailing the 3 blade cost at least half a knot when I was in wind that would push me normally at 5.5K
Sailing the acceleration in the puffs was noticeably less with the fixed blade.
In light air under say 9K , fix prop performance was well, it was awful. Annoying is maybe the best way to describe it. Over a 10 hour run that extra knot could be 8 to 10 miles. Sometimes that matters.
I replaced the fixed prop with a new Gori this time a 15x12. I get 5.6K @2400rpm which is 80% of max rpm. and she sails like a sailboat! Never had any manoeuvring issues that would relate to the Gori.
Without getting into the details, when the yard reinstalled by 15x11 they made two mistakes. The first one was they did not use two lock set screws so eventually a blade fell off. These set screws that jam on the shaft are different. The first one in is pointed and the pointed end will crush up against the shaft, the "following set screw has a flat head and secures the first one in place. Red Loctite is used on both. They are not reusable, you need new ones every time you install the prop.
I can not imagine how a 14.75x8.5 would even be close to the specs for a Nonsuch 33 with an engine in the 30 plus hp range. Campbell has a good reputation, I think the sizing is way off.
I am biased towards Gori, works like a charm for me, but there are lots of nice props out there,
We have a 17x12 2 blade Flex-O- Fold with our Westerbeke 27A. We get 6 kn at 1800 and 7 kn at 2500. Lots of power and no black smoke. Replaced a 16.5x13 Gori lost in 1997. Great prop!
Dale Myrfield
NS 30C #382
Duck Soup
Collins Bay Ontario
Hi Mark,
I asked for a quote from Flex-O-Fold on a 17 X 13 3 blade as you indicated you have.
I gave them the boat description with M35 Universal 30 HP @ 3200 RPM, Hurth HBW150V transmission @2.13 :1 reduction.
They replied with a quote on a 15 X 11-3R.
Could your 17 X 13 actually be a 2 blade?
My 17 x13 3 blade is really a 17 x 13 3 blade!!
Their original recommendation was a 17 x 12 3 blade. With that prop, the boat barely made 5.5 knots.
I cannot see how a 15x11 would remotely be appropriate.
I have had mine for >10 years.
MF
Same engine and transmission.
Engine rated 30 hp at 3200 rpm.
If prop is correctly sized, you should come very close to 3200 at max throttle.
Mine is between 3100 and 3200.
Cruising rpm is 80% max throttle.
I run it at 2500 rpm.
If prop too big, you won’t get to 3200.
If too small, max rpm will be >3200
MF