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 >
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