Need Advice for Reprop of ‘08 h36

Dan_Y

.
Oct 13, 2008
519
Hunter 36 Hampton
Our h36 came with a Yanmar 3YM30 and Michigan Wheel DJ355 (see attached). The MI wheel is a 16”, 9 pitch, RH fixed prop. Has anyone upgraded to a flexofold or Campbell sailor? If so, would you mind sharing the specs?

It’s odd to me that when I use the MI wheel prop calculator it wants to increase the diameter to 18” and pitch to 11 or 12. WOT is 3600 RPM, but I usually stay at 3000 and never get black smoke, probably indicating I’m not overpropped. 3200 is the max I have used and no issues there. Dealer told me to stay at 3000 RPM. We make about 6-7 knots when clean.
thanks,
Dan
 

Attachments

May 17, 2004
5,736
Beneteau Oceanis 37 Havre de Grace
We have a 3YM30 on a 37’ Beneteau. It came with a 17x12 3 blade fixed prop. We upgraded to a 16x12 3 blade Flex o Fold and are very happy. With both props we can reach 3600 at WOT, and we usually cruise at 2800. Both props got us to about 7.1 kts at that RPM. The fof sails m much faster.

We contacted Flex-o-fold with our engine and transmission specs and they gave the size recommendation.
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,390
CAL 35 Cruiser #21 moored EVERETT WA
Dan.
My Cal35C came with a Michigan wheel. After running with it for a couple years, I decided to look for a better solution.
C01D7F6F-743C-44A9-81B7-EE8489770367.jpeg

It had considerable prop walk. I learned to use it to manage the boat when docking. When full throttle there was smoke and fuel out the back leaving an ugly line of stain across the stern. Never really got to full hull speed.

The folks at WestbyNorth are up in BC, north of me. They make a pretty bronze CampbellSailor.
1010FC32-94A8-4C6B-B564-E0A1D6B4EDA1.jpeg
The engineer asked a number of questions about my engine, transmission, space for the prop in order to identify the best prop for my rig.

2922CDBE-C1D8-486B-9CB7-A30D78BF72B0.jpeg



I am very pleased. I get great thrust in forward and even reverse. I no longer have the ugly stain on my stern. The smoke and unburnt fuel is gone. I get about 1.5knots better out of the boat easily reaching hull speed. The stern no longer drops 12" to 14" when I power up to cruising speed. It is the prop design, more thrust than drag.

I even improved the speed under sail by around a knot. The engineer suggested I might get a 30% improvement. I feel I got all of that and then some.

If you need power when under power, then I recommend the Campbell Sailor. If you want to optimize the sailing speed of the boat then you need to look at one of the folding type props.
 
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Dan_Y

.
Oct 13, 2008
519
Hunter 36 Hampton
Wow, the Oceanis came with a 17x12 on the 3YM30, and more amazing is the CS on Hadley is 20x13. I must be under propped. The MW DJ takes a long while to respond in reverse and by that time wind and current have caused many “go arounds”. Like others I’m looking for improved reverse. I’m the docking show too often rather than watching the show. Thanks for the input so far.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,390
CAL 35 Cruiser #21 moored EVERETT WA
The prop fits the space I have from the shaft to the hull. The additional thrust verse prop walk has been interesting to learn to use.
 
May 17, 2004
5,736
Beneteau Oceanis 37 Havre de Grace
Wow, the Oceanis came with a 17x12 on the 3YM30, and more amazing is the CS on Hadley is 20x13. I must be under propped. The MW DJ takes a long while to respond in reverse and by that time wind and current have caused many “go arounds”. Like others I’m looking for improved reverse. I’m the docking show too often rather than watching the show. Thanks for the input so far.
Prop walk with the FOF in reverse is about half of what we had with the fixed prop. It’s still noticeable but manageable (especially with a bow thruster), and there are times when it’s useful. Reverse torque is less than the fixed prop but adequate. At idle in reverse the FOF unfolds but does not pull much. I generally go up to about 1500 RPMs to back out of the slip and maybe 1200 to slow down when docking. That still leaves plenty of headroom for emergencies. I have never needed red line in reverse.
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,390
CAL 35 Cruiser #21 moored EVERETT WA
I have never needed red line in reverse.
You should not need to do that. When I installed the new prop, I took the boat out into open water and tried some emergency stops. From 6 knots, I could put the boat in reverse and stop her in 2 boat lengths. It is an interesting exercise. One I try at least once a year to remind me how fast and careful I need to be keeping watch.
 
Apr 8, 2011
774
Hunter 40 Deale, MD
So yes, 08 H36 and replaced with Flex-o-fold 3-blade. Love it. I recommend you e-mail flex-o-fold directly, provide the info they need and they’ll spec the right prop. They’ll need to know your transmission specs, for example. 3,000 rpm is my cruise speed too. You didn’t mention whether your fixed blade is 2 or 3-blade, but I have a 3-blade fixed for sale if you were interested. My FoF prop is:

1651452222723.png
 

Dan_Y

.
Oct 13, 2008
519
Hunter 36 Hampton
My MW is a 3 blade. I made the assumption the h36s all had 3 blade. The FoF price is about half of what i thought it was. Good news! thanks for that info!
 
Apr 8, 2011
774
Hunter 40 Deale, MD
My MW is a 3 blade. I made the assumption the h36s all had 3 blade. The FoF price is about half of what i thought it was. Good news! thanks for that info!
Yeah, I looked at all of the options, and FoF came out as the best value in my research. Nothing against the other folding and feathering props - they all have their fans, and deservedly so. But this is the study that made up my mind:


Also, MaineSail had a two-blade FoF and the vibration problems he experience caused him to pull it off and go with something different. For that reason I didn't consider a two-blade FoF and went for the 3-blade. It has been one of the best upgrades I've made to the boat - something that affects the boat positively under sail with increased speed (and reduced noise from the elimination of the freely spinning fixed 3-blade) and under power - I get to hull speed with less RPMs and have a higher cruise speed at the same RPMs. Propwalk is also reduced from the fixed 3-blade.
 
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Dec 19, 2006
5,832
Hunter 36 Punta Gorda
I added a Flex O Fold. on my 07 H-36 back in 08 it was
16x11 RH 3 blade 1” shaft
Been great no need for maintance just keep clean.
Nick
 
Jan 5, 2017
151
Hunter 356 SF Bay / Delta
We also have the flex-o-fold 3-blade 16x11-3R on our 356.We're satisfied with it, but I wouldn't say it was as big an upgrade as we were expecting over our factory fixed 2-blade.