Hi The max RPM is 3200 and we could get to that value no problem, didn’t want to hold it there for too long, just a few minutes. We did a 20 min test at 3000 RPM where we held 6.8 knots. No problems were found and although very loud she ran well. There was no current, wind or waves to speak of. Cheers, Bill
On Aug 15, 2014, at 10:28 AM, Josh Muckley <muckl...@gmail.com> wrote: > Be careful over pitching it cause continuously running the engine below 80% > of full load can cause other problems such as coking up the exhaust elbow and > glazing the cylinders. Lots of people like the idea of over pitching the > prop to run a little faster at a lower rpm. I say, the difference in speed > is minimal and as for fuel efficiency, with these little engines your > probably not gonna use a full tank in a season anyway. So that causes > problems too. > > For me I want to be able to reach instantanious max rpm. I won't run there > but I could get there if I had to. > > Also as the bottom gets dirty you'll slow down, rpms will need to go up to > maintain speed...but you probably won't be able to speed up once the bottom > gets dirty enough. If you overpitch the prop then at this point you will be > overloaded, below max rpm, and start blowing black smoke. > > I'm kinda with Joel. At most you might want to go the other way and > underpitch it a step. > > Josh Muckley > S/V Sea Hawk > 1989 C&C 37+ > Solomons, MD > > On Aug 15, 2014 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] 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 > >
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