Bill, Couple thoughts: If you are getting a max of 3000 rpm you already have too much pitch. I would not go up; I might go down one click. You should cruise at 80% of max rpm or 2500-2600 rpm.
I have a 35/3 with a max-prop set to 14 degrees, but my reduction gear is 2.6:1 I get to 3500 rpm with a rating of 3600 rpm. Joel On Fri, Aug 15, 2014 at 12:30 PM, Bill Hoyne via CnC-List < cnc-list@cnc-list.com> wrote: > Hi All, > Here are the results of my Max Prop issues. > > I have a C&C 35 Mk II with a Volvo Penta 2003 28hp with a 2.4:1 reduction > MS2B transmission max RPM is 3200. The prop is a left rotation. The Max > Prop is 14” and set to 24 deg (X=C, Y=E). This gives 11.6” pitch. The > original settings were way off with wrong settings for any degree and thus > the issues. > Now I am getting 3000rpm = 6.8-6.9 knots, 2800 rpm = 6.4 knots, 2600rpm = > 6.0 knots. > > How are does this compare with what you guys are seeing? Do you guys thing > I can go up to 26 deg and get better speed at some what lower RPM? 3000 rpm > is rather loud ( especially if you are motoring for several hours), 26-2700 > is much easier on the ears but still loud. (Any ideas on what is best to > sound proof the engine compartment?) > > Cheers, > Bill > > PS I just did my first cruise. An 11 day trip in the Gulf Islands. Lots of > fun!! No dents or dings and the boat still floats!! > > *Bill Hoyne* > Mithrandir > ’74 C&C35 MkII > in Victoria,BC > > > On Jul 28, 2014, at 11:23 AM, Bill Hoyne via CnC-List < > cnc-list@cnc-list.com> wrote: > > I think that will be the plan of attack. > > On Jul 28, 2014, at 10:24 AM, Martin DeYoung via CnC-List < > cnc-list@cnc-list.com> wrote: > > I agree with Josh on contacting Hutch at PYI to get the best info. Your > description of being unable to reach full RPM when in gear does sound like > a reduction in pitch is called for. > > I have changed the pitch on Calypso’s MAX Prop several times including the > original effort at installation. For a few years I intentionally ran 10% > over pitch to reduce cruise speed RPM. Before we went around Vancouver > Island (2011) I reduced pitch by one increment to be sure we could achieve > full RPM (horsepower) when motoring into bigger waves and higher winds. > The reduction to cruise speed (at a smooth engine RPM) was about .2 knot > with no measurable change in fuel consumption. > > The MAX prop owner’s manual has the chart that describes the X Y > relationship to pitch. I have heard tales of divers willing and able to > change the pitch on a classic MAX prop underwater. I would not attempt it > myself and in the past set up a deal with a yard to haul and hold in the > slings for the change then re-launch. It may take several haul/launch > cycles if you want to fully optimize the pitch. > > Martin > Calypso > 1971 C&C 43 > Seattle > > <image001.png> > > *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com > <cnc-list-boun...@cnc-list.com>] *On Behalf Of *Josh Muckley via CnC-List > *Sent:* Sunday, July 27, 2014 9:22 PM > *To:* C&C List; Bill Hoyne > *Subject:* Re: Stus-List Prop Grease (Now Max-Prop settings) > > > Bill, > > Contact Fred "Hutch" Hutchinson at PYI. He'll be able to tell you > immediately where to start. > > hu...@pyiinc.com > > Josh Muckley > S/V Sea Hawk > 1989 C&C 37+ > Solomons, MD > On Jul 28, 2014 12:16 AM, "Bill Hoyne via CnC-List" <cnc-list@cnc-list.com> > wrote: > Hi All, > I have a Max Prop of unknown diameter (forgot to measure when I had the > boat out of the water). I also have a Volvo Penta 2003 and when I run the > engine in idle I get 3000+ RPM,s but when I run it in gear I only get > 1900-2000 RPM’s. I suspect the pitch is a little high. ( A dripless seal, > new shaft and cutless bering were installed last year and in the process > the max-prop was taken off and may not have been installed with the > original specs of which I don’t have from the PO.) My question in does > anybody out there know what the X,Y values should be for a typical C&C > MKII? I would like a starting point to compare what is in the prop now and > where I should head to. The other question is can I do thin in the water or > do I need to haul the boat? > Thanks, > Bill > > *Bill Hoyne* > Mithrandir > ’74 C&C35 MkII > in Victoria,BC > > > _______________________________________________ > This List is provided by the C&C Photo Album > > Email address: > CnC-List@cnc-list.com > To change your list preferences, including unsubscribing -- go bottom of > page at: > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com > > > _______________________________________________ > This List is provided by the C&C Photo Album > > Email address: > CnC-List@cnc-list.com > To change your list preferences, including unsubscribing -- go bottom of > page at: > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com > > > > _______________________________________________ > This List is provided by the C&C Photo Album > > Email address: > CnC-List@cnc-list.com > To change your list preferences, including unsubscribing -- go bottom of > page at: > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com > > > -- Joel 301 541 8551
_______________________________________________ This List is provided by the C&C Photo Album Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com
