I confirmed the prop on Sapphire is a flexofold 3 blade 16 degree pitch x 11” blades
I do about 6.8 knts around 2,200 rpm in a flat sea, in a head sea around 5.4 or less but need to increase rpm. -Rob Sent from my iPhone > On Aug 20, 2025, at 9:23 PM, CHARLES SCHEAFFER via CnC-List > <cnc-list@cnc-list.com> wrote: > > > I have the smaller 34R with a 27Hp diesel. The transmission is slightly > above 2:1. I have a 15" two blade prop and set it to 18 degrees, I think. > The setting from PYI when I got the prop was a little aggressive and I > dropped it 2 degrees. > > If I let the bottom get horrible, the first sign is slow speed and wiping off > the scum makes a huge difference. Generally I can get good speed with a > clean bottom up to about 6.6 at 2800 rpm. I get better speed sailing, as the > two blade lacks area to really push the hull. Compared to similar boats, I > got the wrong prop and a 16" would have been better for my boat. The two > blade is preferred for racing, as you can set the blades vertically and > decrease the drag. > > Based on your email, I think you lowered the pitch rather than increased it. > > Chuck Scheaffer, Resolute 1989 C&C 34R, Magothy River, Md > > > > >> On 08/20/2025 4:10 PM EDT rockland bazemore via CnC-List >> <cnc-list@cnc-list.com> wrote: >> >> >> Wondering what setups you all have with this configuration. >> We have a newer 16" Maxprop (I never measured) with recently adjusted to 14º >> pitch based on Rob's 37+ setup. He does a lot closer to hull speed. >> >> When we left for our trip in Annapolis we could do 5.2kn. The bottom was >> cleaned about 3 weeks prior. >> I changed the pitch to 14º in Block Is. >> Couple weeks later and now we only do 4.2kn in slack water. >> The bottom doesn't seem to be THAT bad. The prop and shaft are very clean. >> I'm wondering now if its possible transmission slipping? The ATF oil smells >> fine. >> >> Gear ratio 2.14 Prop shaft 1-1/8" >> >> Ideas? >> >> -- >> Rockland Bazemore >> S/V Blue Pearl >> C&C 37/40+ >> Annapolis, MD >> Your contributions help pay the fees associated with this list and help to >> keep it active. Please help by making a small contribution using PayPal at: >> https://www.paypal.com/paypalme/stumurray All contributions are greatly >> appreciated. > Your contributions help pay the fees associated with this list and help to > keep it active. Please help by making a small contribution using PayPal at: > https://www.paypal.com/paypalme/stumurray All contributions are greatly > appreciated.
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