Stus-List PROPELLER PITCH
Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the proper propeller pitch should be? She has an aftermarket Maxiprop, and based on engine performance, I believe the pitch may be set too high. Richard Luna, Lake Champlain, VT ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Stus-List Propeller Pitch
Thanks for all the helpful comments and thoughts. Luna's problem is that she cruises under power at about 5.5 kts at 1500rpm, but starts to smoke and overheat above that. She'll do about 6kts at 1800rpm. Next time I pull her out, I'll have a closer look at the prop. I have the original owner's manual, but the chart showing the propeller specifications is gone. Does anyone with a 35MK III have the original propeller specifications? ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List propeller / pitch
Can your SB8 achieve full rated RPM either in calm or choppy conditions? Calypso's 3 blade MAX prop was intentionally over pitched (by 10%) for many years. I did this to allow calm water hull speed at an engine RPM "smooth spot". Worked fine for most PNW inland waters. For our trip around Vancouver Island I wanted to be sure Calypso could power upwind effectively in all wind/sea conditions. I "down shifted" the prop by 15% (now 5% under pitch). The 20 year old Perkins 4-108 could now run up to full rated RPM (3600) while powering into a wind and sea. I did not observe a significant change in fuel usage but we did choose to use 6.6 to 6.8 knots (down from 7 to 7.2) as our target powering speed through the water. My key point is: If your engine cannot reach full RPM it is not achieving full rated horsepower. The pitch of a prop may be more important than the diameter or number of blades. Martin Calypso 1970 C&C 43 Seattle -Original Message- From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Allen White Sent: Wednesday, February 13, 2013 3:38 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List propellers I have a 26 with a single cylinder SB8 that is not able to push the boat to hull speed easily in wind and chop. Has anyone specs on what prop should be on the boat, and any possible upgrades. The current prop is a 2 blade fixed, unsure of the specs. I cruise more than race, and seem to wind up motoring home often when the wind gives up on me. I love the boat and would welcome any advise you guys can offer. Allen C&C 26 Windfall - ___ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com ___ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com
Re: Stus-List propeller / pitch
That's what makes me want to question the prop. I can achieve about 4 - 4.5 in most conditions, but increasing RPM doesn't seem to increase boat speed. I do not have a tachometer, we use the shakeometer to find comfortable RPM. I only got the boat late last summer and did not get nearly as much time on it as I wanted. I am extremely happy with the sailing performance, but I guess small sailboats just don't motor well. Certainly not why we have sailboats anyway. I have sailed at 5.5 - 6 comfortably and exceeded that downwind. I was thinking I should be able to motor easily in the 5 - 5.5 area. Am I wrong ? I sail in the Hudson River and buck tidal currents often. Every little bit helps when the missus is tired of the diesel Allen C&C 26 Windfall Poughkeepsie Yacht Club Hyde Park, NY -Original Message- From: Martin DeYoung [mailto:mdeyo...@deyoungmfg.com] Sent: Wednesday, February 13, 2013 6:31 PM To: awh...@thegateguys.com; cnc-list@cnc-list.com Subject: RE: Stus-List propeller / pitch Can your SB8 achieve full rated RPM either in calm or choppy conditions? Calypso's 3 blade MAX prop was intentionally over pitched (by 10%) for many years. I did this to allow calm water hull speed at an engine RPM "smooth spot". Worked fine for most PNW inland waters. For our trip around Vancouver Island I wanted to be sure Calypso could power upwind effectively in all wind/sea conditions. I "down shifted" the prop by 15% (now 5% under pitch). The 20 year old Perkins 4-108 could now run up to full rated RPM (3600) while powering into a wind and sea. I did not observe a significant change in fuel usage but we did choose to use 6.6 to 6.8 knots (down from 7 to 7.2) as our target powering speed through the water. My key point is: If your engine cannot reach full RPM it is not achieving full rated horsepower. The pitch of a prop may be more important than the diameter or number of blades. Martin Calypso 1970 C&C 43 Seattle -Original Message- From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Allen White Sent: Wednesday, February 13, 2013 3:38 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List propellers I have a 26 with a single cylinder SB8 that is not able to push the boat to hull speed easily in wind and chop. Has anyone specs on what prop should be on the boat, and any possible upgrades. The current prop is a 2 blade fixed, unsure of the specs. I cruise more than race, and seem to wind up motoring home often when the wind gives up on me. I love the boat and would welcome any advise you guys can offer. Allen C&C 26 Windfall - ___ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com ___ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com
Re: Stus-List PROPELLER PITCH
Try this propellor calculator. rbbi.com/folders/prop/propcalc.htm Sent from my T-Mobile 4G LTE DeviceDoug Mountjoy POYC Rebecca Leah Lf39 Original message From: Bunky via CnC-List Date: 12/17/17 14:18 (GMT-08:00) To: cnc-list@cnc-list.com Cc: Bunky Subject: Stus-List PROPELLER PITCH Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the proper propeller pitch should be? She has an aftermarket Maxiprop, and based on engine performance, I believe the pitch may be set too high. Richard Luna, Lake Champlain, VT ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Be sure you know your transmission ratio, prop-hull clearance, ideal engine RPM, etc. before you rely on a simple calculation. This is a question that seems like it should have a simple answer but "...it depends on several other parameters.." so a simple answer could be wrong. If the Max-Prop allows, you might just change the pitch and see if the performance improves. Sent from my iPhone > On Dec 17, 2017, at 5:18 PM, Bunky via CnC-List wrote: > > Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the > proper propeller pitch should be? She has an aftermarket Maxiprop, and based > on engine performance, I believe the pitch may be set too high. > > Richard > Luna, Lake Champlain, VT > > ___ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
While motoring in forward gear, run the engine at full throttle. Your engine should be able to reach maximum, or close to maximum rated rpm. If not, your pitch is to high. If the engine runs much higher than maximum rated rpm at full throttle, your pitch is too low. Alan Bergen 35 Mk III Thirsty Rose City YC Portland, OR On Sun, Dec 17, 2017 at 2:18 PM, Bunky via CnC-List wrote: > Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what > the proper propeller pitch should be? She has an aftermarket Maxiprop, and > based on engine performance, I believe the pitch may be set too high. > > Richard > Luna, Lake Champlain, VT > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://urldefense. > proofpoint.com/v2/url?u=https-3A__www.paypal.me_stumurray&d= > DwICAg&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=9w3G7 > Cf8YfQnrjmtuNxwDJYr3JMv9f1pAfgAJ9xXYQQ&m=SIgdw_VNv2aYuYBIiP9 > 132yL5Tf25-eb158mHK45k-4&s=veOqs6D_FOgishyZRlxruce5bZIVYxeuZ3Ha5pbNrvA&e= > > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
With a standard 4.61 transmission ratio, I use a 17" Max Prop set to 10 pitch (18° blade angle). 2500 RPM gives me 6 knots in fairly smooth water. Jim Watts Paradigm Shift C&C 35 Mk III Victoria, BC On 17 December 2017 at 16:21, ALAN BERGEN via CnC-List < cnc-list@cnc-list.com> wrote: > While motoring in forward gear, run the engine at full throttle. Your > engine should be able to reach maximum, or close to maximum rated rpm. If > not, your pitch is to high. If the engine runs much higher than maximum > rated rpm at full throttle, your pitch is too low. > > Alan Bergen > 35 Mk III Thirsty > Rose City YC > Portland, OR > > On Sun, Dec 17, 2017 at 2:18 PM, Bunky via CnC-List > wrote: > >> Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what >> the proper propeller pitch should be? She has an aftermarket Maxiprop, and >> based on engine performance, I believe the pitch may be set too high. >> >> Richard >> Luna, Lake Champlain, VT >> >> ___ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - >> use PayPal to send contribution -- https://urldefense.proofpoint >> .com/v2/url?u=https-3A__www.paypal.me_stumurray&d=DwICAg& >> c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=9w3G7Cf8YfQn >> rjmtuNxwDJYr3JMv9f1pAfgAJ9xXYQQ&m=SIgdw_VNv2aYuYBIiP9132yL5T >> f25-eb158mHK45k-4&s=veOqs6D_FOgishyZRlxruce5bZIVYxeuZ3Ha5pbNrvA&e= >> >> > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Call Fred at PYI, he is a veritable font of information. You'll need to know the prop diameter and transmission reduction; he will have a table with your boat and engine on it. He was terrifically helpful when I put the new engine in Peregrine. Andy C&C 40 Peregrine Andrew Burton 61 W Narragansett Newport, RI USA02840 http://sites.google.com/site/andrewburtonyachtservices/ +401 965-5260 > On Dec 17, 2017, at 17:56, svpegasus38 via CnC-List > wrote: > > Try this propellor calculator. > rbbi.com/folders/prop/propcalc.htm > > > > Sent from my T-Mobile 4G LTE Device > Doug Mountjoy > POYC > Rebecca Leah > Lf39 > > Original message > From: Bunky via CnC-List > Date: 12/17/17 14:18 (GMT-08:00) > To: cnc-list@cnc-list.com > Cc: Bunky > Subject: Stus-List PROPELLER PITCH > > Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what > the proper propeller pitch should be? She has an aftermarket Maxiprop, > and based on engine performance, I believe the pitch may be set too high. > > Richard > Luna, Lake Champlain, VT > > ___ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Your engine manual should have a max achievable RPM listed. If you mash the throttle and can't get to that RPM, you need to dial in finer pitch. Andrew Burton 61 W Narragansett Newport, RI USA02840 http://sites.google.com/site/andrewburtonyachtservices/ +401 965-5260 > On Dec 17, 2017, at 18:23, Charles Nelson via CnC-List > wrote: > > Be sure you know your transmission ratio, prop-hull clearance, ideal engine > RPM, etc. before you rely on a simple calculation. This is a question that > seems like it should have a simple answer but "...it depends on several other > parameters.." so a simple answer could be wrong. If the Max-Prop allows, you > might just change the pitch and see if the performance improves. > > Sent from my iPhone > >> On Dec 17, 2017, at 5:18 PM, Bunky via CnC-List >> wrote: >> >> Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the >> proper propeller pitch should be? She has an aftermarket Maxiprop, and based >> on engine performance, I believe the pitch may be set too high. >> >> Richard >> Luna, Lake Champlain, VT >> >> ___ >> >> Thanks everyone for supporting this list with your contributions. Each and >> every one is greatly appreciated. If you want to support the list - use >> PayPal to send contribution -- https://www.paypal.me/stumurray >> > > ___ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Or contact jerome blakely, max-prop service mgr at pyi. Phone # 425.355.3669. They are rebuilding my max-prop now.Jim schwartz38 LFSEA YA!washington nc Original message From: Andrew Burton via CnC-List Date: 12/17/17 7:46 PM (GMT-05:00) To: cnc-list@cnc-list.com Cc: Andrew Burton Subject: Re: Stus-List PROPELLER PITCH Call Fred at PYI, he is a veritable font of information. You'll need to know the prop diameter and transmission reduction; he will have a table with your boat and engine on it. He was terrifically helpful when I put the new engine in Peregrine.AndyC&C 40Peregrine Andrew Burton61 W NarragansettNewport, RI USA 02840 http://sites.google.com/site/andrewburtonyachtservices/+401 965-5260 On Dec 17, 2017, at 17:56, svpegasus38 via CnC-List wrote: Try this propellor calculator. rbbi.com/folders/prop/propcalc.htm Sent from my T-Mobile 4G LTE DeviceDoug Mountjoy POYC Rebecca Leah Lf39 Original message From: Bunky via CnC-List Date: 12/17/17 14:18 (GMT-08:00) To: cnc-list@cnc-list.com Cc: Bunky Subject: Stus-List PROPELLER PITCH Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the proper propeller pitch should be? She has an aftermarket Maxiprop, and based on engine performance, I believe the pitch may be set too high. Richard Luna, Lake Champlain, VT ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Max rpm is 3600 for that engine. On Sun, Dec 17, 2017 at 8:09 PM detroito91 via CnC-List < cnc-list@cnc-list.com> wrote: > Or contact jerome blakely, max-prop service mgr at pyi. Phone # > 425.355.3669. They are rebuilding my max-prop now. > Jim schwartz > 38 LF > SEA YA! > washington nc > > Original message > From: Andrew Burton via CnC-List > Date: 12/17/17 7:46 PM (GMT-05:00) > To: cnc-list@cnc-list.com > Cc: Andrew Burton > Subject: Re: Stus-List PROPELLER PITCH > > Call Fred at PYI, he is a veritable font of information. You'll need to > know the prop diameter and transmission reduction; he will have a table > with your boat and engine on it. He was terrifically helpful when I put the > new engine in Peregrine. > Andy > C&C 40 > Peregrine > > Andrew Burton > 61 W Narragansett > Newport, RI > USA02840 > > http://sites.google.com/site/andrewburtonyachtservices/ > +401 965-5260 > > On Dec 17, 2017, at 17:56, svpegasus38 via CnC-List > wrote: > > Try this propellor calculator. > rbbi.com/folders/prop/propcalc.htm > > > > Sent from my T-Mobile 4G LTE Device > Doug Mountjoy > POYC > Rebecca Leah > Lf39 > > ---- Original message > From: Bunky via CnC-List > Date: 12/17/17 14:18 (GMT-08:00) > To: cnc-list@cnc-list.com > Cc: Bunky > Subject: Stus-List PROPELLER PITCH > > Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what > the proper propeller pitch should be? She has an aftermarket Maxiprop, > and based on engine performance, I believe the pitch may be set too high. > > Richard > Luna, Lake Champlain, VT > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > -- Joel 301 541 8551 ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Hi I have 3GM30F with Kanzaki KM3P transmission and 1 inch shaft. Boat is Frers 33 so a bit different. Prop that came with the boat was Martec Eliptical RH16DX14P-3. This may be of some use. The Martec was replaced last Fall with a Flex-o-Fold (better reverse/less vibration). They spec'd the prop as below: "With a 3GM30F, 27/3600 ( gear reduction ratio 1:2,61 ) we would recommend a 2-blade 16x12R or a 3-blade 16x11-3R propeller for your Frers 33." Note that the Martec has 10 years use and is available if anyone is looking Mike Persistence Halifax, NS http://users.eastlink.ca/~mhoyt -Original Message- From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Bunky via CnC-List Sent: Sunday, December 17, 2017 6:18 PM To: cnc-list@cnc-list.com Cc: Bunky Subject: Stus-List PROPELLER PITCH Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the proper propeller pitch should be? She has an aftermarket Maxiprop, and based on engine performance, I believe the pitch may be set too high. Richard Luna, Lake Champlain, VT ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
The problem that I see with this calculator is that there is no value for prop diameter (and slip is pretty intangible, though I suspect using .10 slip might be a good approximation for 90% efficiency). The rule of thumb that a local propshop told me is that changing prop diameter by 1” is approximately equivalent to changing the prop pitch by 2”. So diameter also enters into the calculation. I believe each prop maker has their own calculator for recommending initial diameter and pitch, based on boat weight, engine HP and targeted cruising RPM, transmission reduction ratio, and hull speed. Rick Brass Washington, NC From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of svpegasus38 via CnC-List Sent: Sunday, December 17, 2017 5:56 PM To: cnc-list@cnc-list.com Cc: svpegasus38 Subject: Re: Stus-List PROPELLER PITCH Try this propellor calculator. rbbi.com/folders/prop/propcalc.htm Sent from my T-Mobile 4G LTE Device Doug Mountjoy POYC Rebecca Leah Lf39 Original message From: Bunky via CnC-List mailto:cnc-list@cnc-list.com> > Date: 12/17/17 14:18 (GMT-08:00) To: cnc-list@cnc-list.com <mailto:cnc-list@cnc-list.com> Cc: Bunky mailto:richard.h.bernst...@uvm.edu> > Subject: Stus-List PROPELLER PITCH Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the proper propeller pitch should be? She has an aftermarket Maxiprop, and based on engine performance, I believe the pitch may be set too high. Richard Luna, Lake Champlain, VT ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Take prop manufacturers recommendations with a grain of salt. Years ago I requested a recommendation from Flexofold. The rep at the time was Chuck Angle who was highly regarded. He said he didn't have a good prop recommendation for my 35-1. :) I went with Martec. In 2011, I repeated the request and got a recommendation for a 15 x 12. In 2016, I again asked and they said 16 x 12. Currently, Touche' is swinging a 14 x 14 Martec which seems a bit under pitched (or too small a diameter). I can run at 6.4-6.5 knots at cruise rpm (80% max, 2450 rpm) and flat water, no wind. On my list for next year's haul out is to measure and document (photograph) the prop tip clearance distance. I will also measure the hub and swing pin location. The swing plane for different props varies. I think prop selection is part science, part art and a bit of voodoo. Dennis C. Touche' 35-1 #83 Mandeville, LA On Mon, Dec 18, 2017 at 9:59 AM, Rick Brass via CnC-List < cnc-list@cnc-list.com> wrote: > The problem that I see with this calculator is that there is no value for > prop diameter (and slip is pretty intangible, though I suspect using .10 > slip might be a good approximation for 90% efficiency). > > > > The rule of thumb that a local propshop told me is that changing prop > diameter by 1” is approximately equivalent to changing the prop pitch by > 2”. So diameter also enters into the calculation. > > > > I believe each prop maker has their own calculator for recommending > initial diameter and pitch, based on boat weight, engine HP and targeted > cruising RPM, transmission reduction ratio, and hull speed. > > > > Rick Brass > > Washington, NC > > > > > > > > *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of > *svpegasus38 > via CnC-List > *Sent:* Sunday, December 17, 2017 5:56 PM > *To:* cnc-list@cnc-list.com > *Cc:* svpegasus38 > *Subject:* Re: Stus-List PROPELLER PITCH > > > > Try this propellor calculator. > > rbbi.com/folders/prop/propcalc.htm > > > > > > > > Sent from my T-Mobile 4G LTE Device > > Doug Mountjoy > > POYC > > Rebecca Leah > > Lf39 > > > > Original message > > From: Bunky via CnC-List > > Date: 12/17/17 14:18 (GMT-08:00) > > To: cnc-list@cnc-list.com > > Cc: Bunky > > Subject: Stus-List PROPELLER PITCH > > > > Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what > the proper propeller pitch should be? She has an aftermarket Maxiprop, > and based on engine performance, I believe the pitch may be set too high. > > Richard > Luna, Lake Champlain, VT > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Flexofold has gotten better. When I replaced my prop a year ago, they wanted to know not only shaft size, but also information about my engine and transmission. This is how they responded: Hello Matthew Thank you for the missing gear reduction. With a Westerbeke W40, max rated 37hp/3000rpm (V-drive) ( gear reduction ratio 1:2,00 ) we would recommend a 2-blade 17x12L or a 3-blade 16x12-3L propeller for your C&C 42. I ended up getting the two-blade and am happy with it. The best part is that it’s no big deal if I forget to send somebody down below to turn the shaft when we go racing. From: Dennis C. via CnC-List Sent: Monday, December 18, 2017 11:24 AM To: CnClist Cc: Dennis C. Subject: Re: Stus-List PROPELLER PITCH Take prop manufacturers recommendations with a grain of salt. Years ago I requested a recommendation from Flexofold. The rep at the time was Chuck Angle who was highly regarded. He said he didn't have a good prop recommendation for my 35-1. :) I went with Martec. In 2011, I repeated the request and got a recommendation for a 15 x 12. In 2016, I again asked and they said 16 x 12. Currently, Touche' is swinging a 14 x 14 Martec which seems a bit under pitched (or too small a diameter). I can run at 6.4-6.5 knots at cruise rpm (80% max, 2450 rpm) and flat water, no wind. On my list for next year's haul out is to measure and document (photograph) the prop tip clearance distance. I will also measure the hub and swing pin location. The swing plane for different props varies. I think prop selection is part science, part art and a bit of voodoo. Dennis C. Touche' 35-1 #83 Mandeville, LA On Mon, Dec 18, 2017 at 9:59 AM, Rick Brass via CnC-List wrote: The problem that I see with this calculator is that there is no value for prop diameter (and slip is pretty intangible, though I suspect using .10 slip might be a good approximation for 90% efficiency). The rule of thumb that a local propshop told me is that changing prop diameter by 1” is approximately equivalent to changing the prop pitch by 2”. So diameter also enters into the calculation. I believe each prop maker has their own calculator for recommending initial diameter and pitch, based on boat weight, engine HP and targeted cruising RPM, transmission reduction ratio, and hull speed. Rick Brass Washington, NC From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of svpegasus38 via CnC-List Sent: Sunday, December 17, 2017 5:56 PM To: cnc-list@cnc-list.com Cc: svpegasus38 Subject: Re: Stus-List PROPELLER PITCH Try this propellor calculator. rbbi.com/folders/prop/propcalc.htm Sent from my T-Mobile 4G LTE Device Doug Mountjoy POYC Rebecca Leah Lf39 Original message From: Bunky via CnC-List Date: 12/17/17 14:18 (GMT-08:00) To: cnc-list@cnc-list.com Cc: Bunky Subject: Stus-List PROPELLER PITCH Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the proper propeller pitch should be? She has an aftermarket Maxiprop, and based on engine performance, I believe the pitch may be set too high. Richard Luna, Lake Champlain, VT ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Matthew, They did the same for me in 2011 and 2016. For example here's the 2016 reply: "With a Universal M25XPB, 26/3000 ( gear reduction ratio 1:2,05 ) we would recommend a 2-blade 16x12R propeller for your C&C 35mki. Please confirm the HP/RPM as this engine comes in different variants concerning HP and RPM." The 2011 reply had the same information attached from the submission form. "Thank you for your inquiry regarding a Flexofold propeller for your C&C 35 Mark I. For your boat, with that Universal 25XPB engine, I would recommend a 15 x 11 RH 2-blade Flexofold ($1095 + shipping) Adding the racing blade option for that prop the cost of the prop would come up to 15 x 12 RH or ($1305 + shipping)" So which do you believe? Dennis C. On Mon, Dec 18, 2017 at 11:33 AM, Matthew L. Wolford via CnC-List < cnc-list@cnc-list.com> wrote: > Flexofold has gotten better. When I replaced my prop a year ago, they > wanted to know not only shaft size, but also information about my engine > and transmission. This is how they responded: > > > Hello Matthew > > > > Thank you for the missing gear reduction. > > > > With a Westerbeke W40, max rated 37hp/3000rpm (V-drive) ( gear reduction > ratio 1:2,00 ) we would recommend a 2-blade 17x12L or a 3-blade 16x12-3L > propeller for your C&C 42. > > > I ended up getting the two-blade and am happy with it. The best part is > that it’s no big deal if I forget to send somebody down below to turn the > shaft when we go racing. > > > *From:* Dennis C. via CnC-List > *Sent:* Monday, December 18, 2017 11:24 AM > *To:* CnClist > *Cc:* Dennis C. > *Subject:* Re: Stus-List PROPELLER PITCH > > Take prop manufacturers recommendations with a grain of salt. Years ago I > requested a recommendation from Flexofold. The rep at the time was Chuck > Angle who was highly regarded. He said he didn't have a good prop > recommendation for my 35-1. :) I went with Martec. > > In 2011, I repeated the request and got a recommendation for a 15 x 12. > In 2016, I again asked and they said 16 x 12. > > Currently, Touche' is swinging a 14 x 14 Martec which seems a bit under > pitched (or too small a diameter). I can run at 6.4-6.5 knots at cruise > rpm (80% max, 2450 rpm) and flat water, no wind. > > On my list for next year's haul out is to measure and document > (photograph) the prop tip clearance distance. I will also measure the hub > and swing pin location. The swing plane for different props varies. > > I think prop selection is part science, part art and a bit of voodoo. > > Dennis C. > Touche' 35-1 #83 > Mandeville, LA > > >> >> >> > > -- > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > > ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
Richard My MaxProp was set to 14 degrees. Gear ration was 2.6:1 Joel On Mon, Dec 18, 2017 at 11:24 AM, Dennis C. via CnC-List < cnc-list@cnc-list.com> wrote: > Take prop manufacturers recommendations with a grain of salt. Years ago I > requested a recommendation from Flexofold. The rep at the time was Chuck > Angle who was highly regarded. He said he didn't have a good prop > recommendation for my 35-1. :) I went with Martec. > > In 2011, I repeated the request and got a recommendation for a 15 x 12. > In 2016, I again asked and they said 16 x 12. > > Currently, Touche' is swinging a 14 x 14 Martec which seems a bit under > pitched (or too small a diameter). I can run at 6.4-6.5 knots at cruise > rpm (80% max, 2450 rpm) and flat water, no wind. > > On my list for next year's haul out is to measure and document > (photograph) the prop tip clearance distance. I will also measure the hub > and swing pin location. The swing plane for different props varies. > > I think prop selection is part science, part art and a bit of voodoo. > > Dennis C. > Touche' 35-1 #83 > Mandeville, LA > > On Mon, Dec 18, 2017 at 9:59 AM, Rick Brass via CnC-List < > cnc-list@cnc-list.com> wrote: > >> The problem that I see with this calculator is that there is no value for >> prop diameter (and slip is pretty intangible, though I suspect using .10 >> slip might be a good approximation for 90% efficiency). >> >> >> >> The rule of thumb that a local propshop told me is that changing prop >> diameter by 1” is approximately equivalent to changing the prop pitch by >> 2”. So diameter also enters into the calculation. >> >> >> >> I believe each prop maker has their own calculator for recommending >> initial diameter and pitch, based on boat weight, engine HP and targeted >> cruising RPM, transmission reduction ratio, and hull speed. >> >> >> >> Rick Brass >> >> Washington, NC >> >> >> >> >> >> >> >> *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of >> *svpegasus38 >> via CnC-List >> *Sent:* Sunday, December 17, 2017 5:56 PM >> *To:* cnc-list@cnc-list.com >> *Cc:* svpegasus38 >> *Subject:* Re: Stus-List PROPELLER PITCH >> >> >> >> Try this propellor calculator. >> >> rbbi.com/folders/prop/propcalc.htm >> >> >> >> >> >> >> >> Sent from my T-Mobile 4G LTE Device >> >> Doug Mountjoy >> >> POYC >> >> Rebecca Leah >> >> Lf39 >> >> >> >> Original message >> >> From: Bunky via CnC-List >> >> Date: 12/17/17 14:18 (GMT-08:00) >> >> To: cnc-list@cnc-list.com >> >> Cc: Bunky >> >> Subject: Stus-List PROPELLER PITCH >> >> >> >> Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what >> the proper propeller pitch should be? She has an aftermarket Maxiprop, >> and based on engine performance, I believe the pitch may be set too high. >> >> Richard >> Luna, Lake Champlain, VT >> >> ___ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - >> use PayPal to send contribution -- https://www.paypal.me/stumurray >> >> ___ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - >> use PayPal to send contribution -- https://www.paypal.me/stumurray >> >> >> > > ___ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > > -- Joel 301 541 8551 <(301)%20541-8551> ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
One advantage of using the manufacturer's recommendation though, is that if it isn't quite right, they will usually fix it. My three bladed Gori would not quite get up to max RPM, and smoked a little bit, so I sent it back. They sent it over to Denmark or wherever they make them and took a half an inch off the OD, airmailed it back, and it worked perfectly Bill ColemanC&C 39 Original message From: "Dennis C. via CnC-List" Date: 12/18/17 11:24 (GMT-05:00) To: CnClist Cc: "Dennis C." Subject: Re: Stus-List PROPELLER PITCH Take prop manufacturers recommendations with a grain of salt. Years ago I requested a recommendation from Flexofold. The rep at the time was Chuck Angle who was highly regarded. He said he didn't have a good prop recommendation for my 35-1. :) I went with Martec. In 2011, I repeated the request and got a recommendation for a 15 x 12.In 2016, I again asked and they said 16 x 12. Currently, Touche' is swinging a 14 x 14 Martec which seems a bit under pitched (or too small a diameter). I can run at 6.4-6.5 knots at cruise rpm (80% max, 2450 rpm) and flat water, no wind. On my list for next year's haul out is to measure and document (photograph) the prop tip clearance distance. I will also measure the hub and swing pin location. The swing plane for different props varies. I think prop selection is part science, part art and a bit of voodoo. Dennis C.Touche' 35-1 #83Mandeville, LA On Mon, Dec 18, 2017 at 9:59 AM, Rick Brass via CnC-List wrote: The problem that I see with this calculator is that there is no value for prop diameter (and slip is pretty intangible, though I suspect using .10 slip might be a good approximation for 90% efficiency). The rule of thumb that a local propshop told me is that changing prop diameter by 1” is approximately equivalent to changing the prop pitch by 2”. So diameter also enters into the calculation. I believe each prop maker has their own calculator for recommending initial diameter and pitch, based on boat weight, engine HP and targeted cruising RPM, transmission reduction ratio, and hull speed. Rick BrassWashington, NC From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of svpegasus38 via CnC-List Sent: Sunday, December 17, 2017 5:56 PM To: cnc-list@cnc-list.com Cc: svpegasus38 Subject: Re: Stus-List PROPELLER PITCH Try this propellor calculator. rbbi.com/folders/prop/propcalc.htm Sent from my T-Mobile 4G LTE DeviceDoug Mountjoy POYC Rebecca Leah Lf39 Original message From: Bunky via CnC-List Date: 12/17/17 14:18 (GMT-08:00) To: cnc-list@cnc-list.com Cc: Bunky Subject: Stus-List PROPELLER PITCH Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what the proper propeller pitch should be? She has an aftermarket Maxiprop, and based on engine performance, I believe the pitch may be set too high. Richard Luna, Lake Champlain, VT ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List PROPELLER PITCH
It is not an exact science, IIRC power boaters will use loaner props and swap them around to find the best one. It is very hard on a diesel to not be able to hit the factory spec max RPMs, gasoline engines tolerate this much better. Joe Coquina From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Joel Aronson via CnC-List Sent: Monday, December 18, 2017 12:45 PM To: cnc-list@cnc-list.com Cc: Joel Aronson Subject: Re: Stus-List PROPELLER PITCH Richard My MaxProp was set to 14 degrees. Gear ration was 2.6:1 Joel On Mon, Dec 18, 2017 at 11:24 AM, Dennis C. via CnC-List mailto:cnc-list@cnc-list.com>> wrote: Take prop manufacturers recommendations with a grain of salt. Years ago I requested a recommendation from Flexofold. The rep at the time was Chuck Angle who was highly regarded. He said he didn't have a good prop recommendation for my 35-1. :) I went with Martec. In 2011, I repeated the request and got a recommendation for a 15 x 12. In 2016, I again asked and they said 16 x 12. Currently, Touche' is swinging a 14 x 14 Martec which seems a bit under pitched (or too small a diameter). I can run at 6.4-6.5 knots at cruise rpm (80% max, 2450 rpm) and flat water, no wind. On my list for next year's haul out is to measure and document (photograph) the prop tip clearance distance. I will also measure the hub and swing pin location. The swing plane for different props varies. I think prop selection is part science, part art and a bit of voodoo. Dennis C. Touche' 35-1 #83 Mandeville, LA ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
Re: Stus-List Propeller Pitch
You REALLY need less pitch and/or less diameter, and maybe less blades. This is really really hard on your engine. Joe Coquina -Original Message- From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Bunky via CnC-List Sent: Monday, December 18, 2017 1:25 PM To: cnc-list@cnc-list.com Cc: Bunky Subject: Stus-List Propeller Pitch Thanks for all the helpful comments and thoughts. Luna's problem is that she cruises under power at about 5.5 kts at 1500rpm, but starts to smoke and overheat above that. She'll do about 6kts at 1800rpm. Next time I pull her out, I'll have a closer look at the prop. I have the original owner's manual, but the chart showing the propeller specifications is gone. Does anyone with a 35MK III have the original propeller specifications? ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray ___ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
