Sounds like you nailed it. I wouldn't change anything. Joel
On Friday, August 15, 2014, Bill Hoyne via CnC-List <cnc-list@cnc-list.com> wrote: > 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 > <javascript:_e(%7B%7D,'cvml','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 > <javascript:_e(%7B%7D,'cvml','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 >> <javascript:_e(%7B%7D,'cvml','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 >> <javascript:_e(%7B%7D,'cvml','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 >> <javascript:_e(%7B%7D,'cvml','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 <javascript:_e(%7B%7D,'cvml','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 >> <javascript:_e(%7B%7D,'cvml','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 >> <javascript:_e(%7B%7D,'cvml','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 >> <javascript:_e(%7B%7D,'cvml','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 >> <javascript:_e(%7B%7D,'cvml','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
