Also remember Yanmar wants to sell more (i.e., bigger) engine. :) Dennis C.
On Mon, Jan 12, 2015 at 7:12 PM, Josh Muckley <muckl...@gmail.com> wrote: > 37+ = 16700lbs > 1.5 per 1000 = 25hp > 1 per 500 = 33.4hp > > Remember the 3HM35F has funny ratings. IIRC they call it a 30hp engine > but at 3400rpm it's actual output is ~32hp and at 3600rpm it puts out ~34hp. > > Josh > Josh pretty much restated my argument for repowering from an AT4 to a > diesel. My main reasons were flatter torque curve and better fuel > economy. The gasoline flammability issue had very little to do with my > decision. > > Punching into a seaway with an AT4 sucks. To generate the horsepower, an > AT4 needs rpm's. The 1:1 drive just results in making bubbles. A diesel > with a flat torque curve, a reduction gear and a big pitched prop takes a > bigger bite without cavitating. Blenders are great for frozen drinks but > not for driving a boat through waves. > > The admiral and I spent a couple hours punching dead upwind in a narrow > channel one day in 3-4 foot seas and mid-teens on the nose. Sucked. > Sitting back in Mandeville was a brand new 25 hp diesel and all the parts > to repower. We just didn't have time to complete the swap before that trip. > > As for the original thread, Yanmar, I think, recommends 1 hp per 500 lbs > displacement. I think that's a bit light. > > I seem to recall Nigel Calder recommends 1.5 hp per 1000 lbs. > > Dennis C. > Touche' 35-1 #83 > Mandeville, LA > > On Mon, Jan 12, 2015 at 5:46 PM, Jake Brodersen via CnC-List < > cnc-list@cnc-list.com> wrote: > >> Josh, >> >> >> >> Great reply with good detail. I’ve had my share of bashing into heavy >> seas and with just the engine, it can’t be tough going. My 30hp Yanmar >> maintains a steady 3000 rpm, regardless of speed in these conditions. >> Heck, we could be sliding backwards and the engine won’t slow down. Gotta >> love diesel torque. >> >> >> >> I find it easier to motorsail when conditions get extreme. The ride is >> easier and you do go faster. The heel stays fairly constant too. >> >> >> >> Jake >> >> >> >> *Jake Brodersen* >> >> *“Midnight Mistress”* >> >> *C&C 35 Mk-III* >> >> *Hampton VA* >> >> >> >> >> >> >> >> *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of *Josh >> Muckley via CnC-List >> *Sent:* Monday, January 12, 2015 10:46 AM >> *To:* DJ Hawk; C&C List >> *Subject:* Re: Stus-List C&C 37+ engine size >> >> >> >> When you are experiencing heavy currents and can only go 3 kts to round >> the mark. Is that 3 kts being measured by the gps or is it 3 kts measured >> by the speed log? It sounds to me like it is 3kts by gps and if so then >> from all of the other listers comments and my own experience a larger >> engine would only allow you to proceed at 4kts. >> >> When people experience a mismatch between boat size and drive train >> performance it is most often experienced in heavy chop. I believe there >> are two main factors at work in these "under powered" cases. >> >> The first is the diameter of the prop. Smaller engines = smaller props = >> less bite in the water and when things get sloppy the prop slips and >> cavitates more. >> >> The second part is prop speed. In order to use a smaller engine to do >> the same job the designers will gear it to gain mechanical advantage. The >> prop will have to spin faster than its higher powered counterparts. Faster >> prop=less bite and closer to cavitation. >> >> When these two factors are at play the speed log will slow >> disproportionately to the gps speed. Everyone has probably experienced >> plunging the bow into a breaker and seeing the boat speed come down. The >> question is how long does it take go recover. These smaller props spinning >> at higher rpm slip and cavitate more so speed recovery is longer. If the >> next breaker gets to you before the speed recovers.... >> >> Remind me, your boat, Lolita?, has an A4 right? Is it direct drive? If >> my recollections are correct then you have a couple of things that set your >> experiences apart from what you could expect from a larger diesel powered >> boat such as a 37+, 38LF, or a 40. Forgive me if my recollections are >> incorrect. >> >> First is that the gas engines don't have as much low end torque so when >> those breakers come and the boat needs to make up, the engine has a harder >> time coming back up to speed. >> >> Second, the direct drive (1:1) means that right from the start the prop >> has to spin much faster and an increase in load at the prop is directly >> felt as an increase in load at the engine. There are no gears to help in >> having less low end torque so the prop pitch is much less as well, again >> meaning more cavitation. >> >> Third, being a shorter and lighter boat means that the breakers will >> cause the boat to hobby-horse around a lot more and also push the bow off >> requiring more helm. >> >> All of these factors make for a less comfortable ride and slower progress >> in the thick stuff. >> >> Good Luck, >> >> Josh Muckley >> S/V Sea Hawk >> 1989 C&C 37+ >> Solomons, MD >> >> On Jan 12, 2015 7:10 AM, "Danny Haughey via CnC-List" < >> cnc-list@cnc-list.com> wrote: >> >> I think my point is; >> >> >> >> Where we sail there are some pretty good currents and the chop picks up >> quite often. Sometimes, you have to make it home heading into both. >> That's when you want the extra hp. We sometimes have guests that get a >> little nervous when the conditions get exciting and we try to get them in >> as quickly as possible. Sure, you can move along at hull speed in >> favorable conditions but, the only time I'd be able to notice that the >> stern dug in a few inches would be in the harbour, sometimes. We almost >> never experience flat water and are typically dealing with a 3 to 4 knot >> current. Sometimes it is our favor and usually try to time our trips so it >> is. But day sailing, I don't really care as much. I sometimes could only >> get 3 knots under full power trying to round a mark to get into a harbour. >> That can be a little unnerving. >> >> >> >> Danny >> >> >> >> >> >> From my Android phone >> >> >> -------- Original message -------- >> From: Chuck S <cscheaf...@comcast.net> >> Date: 01/11/2015 11:45 PM (GMT-05:00) >> To: Danny Haughey <djhaug...@juno.com>,"CNC boat owners, cnc-list" < >> cnc-list@cnc-list.com> >> Subject: Re: Stus-List C&C 37+ engine size >> >> ". . . bigger is better. . . "? Is a bigger booty better? Will a bigger >> anchor make my sailboat go faster? >> >> What helps sailing is "no engine". Light means flight. >> >> Research the brochures and look to buy a boat with the "designed right >> size engine", not bigger. An upgrade would be a smaller diesel w a turbo. >> Just sayin. >> >> >> >> Chuck >> >> >> >> >> ------------------------------ >> >> *From: *"Danny Haughey via CnC-List" <cnc-list@cnc-list.com> >> *To: *cnc-list@cnc-list.com >> *Sent: *Sunday, January 11, 2015 7:54:45 AM >> *Subject: *Re: Stus-List C&C 37+ engine size >> >> >> >> Ok well, I guess it is adequate then. I just tend to see 40 hp engines >> in most 40 footers. >> >> >> >> Maybe not be the ideal and will be a bargaining point if it comes to that. >> >> >> >> Bigger is better in this instance I think... >> >> >> >> Thanks for the insights guys! >> >> >> >> Danny >> >> >> >> >> >> From my Android phone >> >> >> >> >> -------- Original message -------- >> From: allen via CnC-List <cnc-list@cnc-list.com> >> Date: 01/10/2015 3:53 PM (GMT-05:00) >> To: Robert Abbott <robertabb...@eastlink.ca>,cnc-list@cnc-list.com >> Subject: Re: Stus-List C&C 37+ engine size >> >> >> >> Our 30-2 has 20 hp Universal and easily reaches hull speed in light to >> calm conditions. Originally it was powered by an 18 hp Universal that >> netted 16. >> >> >> >> Allen Miles >> >> s/v Septima >> >> >> >> *From:* Robert Abbott via CnC-List <cnc-list@cnc-list.com> >> >> *Sent:* Saturday, January 10, 2015 3:41 PM >> >> *To:* Danny Haughey <djhaug...@juno.com> ; cnc-list@cnc-list.com >> >> *Subject:* Re: Stus-List C&C 37+ engine size >> >> >> >> Danny: >> Some say if you have one hp per foot of boat, you are adequately powered >> for a sailboat. A 35 hp diesel in a 37+ seems adequate to me. >> >> >> >> Rob Abbott >> AZURA >> C&C 32 - 84 >> Halifax, N.S. >> >> >> >> >> On 2015/01/10 12:30 PM, Danny Haughey via CnC-List wrote: >> >> Hi Guys, >> >> >> >> I'm eyeing a 1989 37+ but it has a 35 HP universal diesel. That, seems >> kind of small for a nearly 40' boat. doesn't it? >> >> >> >> Danny >> >> >> >> >> ------------------------------ >> >> _______________________________________________ >> This List is provided by the C&C Photo Album. >> >> >> >> Please donate to the C&C Photo Album to keep this list free for all >> subscribers. >> >> >> >> 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. >> >> >> >> Please donate to the C&C Photo Album to keep this list free for all >> subscribers. >> >> >> >> 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. >> >> Please donate to the C&C Photo Album to keep this list free for all >> subscribers. >> >> 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. >> >> Please donate to the C&C Photo Album to keep this list free for all >> subscribers. >> >> 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. > > Please donate to the C&C Photo Album to keep this list free for all > subscribers. > > 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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