Yes, the Flex-o-Fold prop also solves the problem (for racing) of a Martec blade hanging down if not aligned.
From: Hoyt, Mike via CnC-List Sent: Thursday, September 19, 2019 10:21 AM To: mailto:cnc-list@cnc-list.com Cc: Hoyt, Mike Subject: Re: Stus-List The Low drag Prop saga is over! Hi Francois Our boat although much smaller than a 34+ (Frers 33) also has 3GM30F with 1:2.61 Kanzaki transmission. We had a Martec RH16D x 14P-3 prop that worked fine in fwd and poorly in reverse. Flex-o-fold sent 16x12 R bladeset and 2 blade hub. It arrived in 3 days after order. It is a bit smoother than the Martec in fwd, has much better reverse and I now know that we don’t have the possibility of one blade hanging down (we could never align shaft due to access). We are very happy with the flex-o-fold. I thought I had heard somewhere that optimum RPM is 80% of WOT. On the 3GM30F with WOT at approx. 3400 RPM that is 2720. We run at 2800RPM. 3100 seems a bit in excess of 80% I also wonder how much difference the size and weight of a boat comes into play. Our 33 is design displacement 9000 lbs and yet has same engine and transmission. Mike Hoyt Persistence 1987 Frers 33 #16 Halifax, NS www.hoytsailing.com From: CnC-List <cnc-list-boun...@cnc-list.com> On Behalf Of Francois Rivard via CnC-List Sent: September 19, 2019 10:23 AM To: captnga...@gmail.com; cnc-list@cnc-list.com Cc: Francois Rivard <jeanfrancoisriv...@gmail.com> Subject: Stus-List The Low drag Prop saga is over! Hi Gary, You're right the 34+, 34/36, 34 R's came with a variety of engines and transmissions. They had me submit both my engine serial # and a picture of the transmission placard. (Yanmar 3GM30F / Kanzaki 2.6:1 Ratio) and they said: "Your engine is the most popular out there, we know what we're doing" They didn't. Max RPM was a struggling and smoking 3000-3100. Yanmar says it should be 3,400 continuous / 3,600 1 hour rating. That + on my boat: the vibrations sounded / looked destructive. I had a lot of time to research all that and this over-pitching thing is a commonly done to make their product look more efficient. The "Voile" French Magazine did a low drag prop test and they stated that a few manufacturers had sent over pitched props / Flex o fold was the worst offender. The comment was that the Flex o Fold was very fuel efficient but: "Be careful with the throttle, the prop is dangerously over-pitched, you could damage your engine". Live and learn.. Francois 1990 34+ "Take Five" Lake Lanier, GA ----------------------------------- Hi Francois, I had the same problem. It turned out my 37+ was delivered with 2 different transmission ratios, and the previous owner had ordered the prop for the wrong ratio. I wonder if the 34+ is available with 2 different transmission ratios. Once they sent me the correct prop she was fine. Agreed, they weren't the most friendly to deal with. Gary S/V Kaylarah '90 C&C 37+ East Greenwich, RI, USA -------------------------------------------------------------------------------- _______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
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