New engine selection for new hull

[tomherrick]

About to send final plans off to a naval architect for advice on a further extension of my C-Dory hull - adding a 30" bracket-like extension to the already extended hull. His comments may nix the project, but indications so far are positive.

I'm interested in hearing from experienced C-Dory owners on what HP they'd recommend if I do the full-regalia extension project.

Background: 1984 22' Angler being extended to a total LOA of 27'10" with no additional width to the beam of 5'6"; 30" of the LOA is a bracket-like extension that's more like an extrusion of the hull. It'll give me a stable swim-step to get on and off dinghies and kayaks, plus adding further buoyancy. Here's the proposed plan:


The extension includes 30" addition to the cabin to expand the galley and - more importantly - to add a head/shower.

I'd been hoping that a 115HP main would adequately do the job of propulsion, but the more research I do, the less confidence I have in that spec. I'm not into POWER for its sake, but just enough to be safe and efficient. Thought you folks might have a coupla cents to throw into the thought process...

Thanks,

T

[Aurelia]

Assuming you load it and use it similarly to how you use it now, I would think a 115 could do just fine. But... if you increase your load significantly, maybe moving up near the 150 class would be appropriate. Beam is unchanged and weight will go up slightly. A 22 cruiser runs great with 90hp and so does my 19 at three feet shorter with the same beam. That would be simply an example of same engine working similarly for shortened/lengthened version of the same hull.

A local 27 footer, plus bracket, runs a 225 but that boat is designed and equipped differently than your proposed extended classic.

Greg

[tsturm]

[thataway]

Fantastic project--and from your track record, it will be very well done--and thought out! I cannot wait to see the photos, and read about the project!

My own tendency would be to go with as light weight a 115. You will be adding some weight--but not up to the amount of a 25. Your running surface will also be lengthened--probably keeping the same flat bottom you have now. You will also be adding floatation aft. For those who don't know this is a 1984 boat, so has the flat bottom of a semi dory--rather than the Modified V of the post 1987 boats, These boats started running with 70 to 75 hp. With the new hull bracket and the prior modification, you should be able to engineer this to handle 150 if you want.

The other would be a light weight 150 like the E-Tec Evinrude--and you would have plenty of power, even heavily loaded. The Suzuki 115 is only about 17 lbs lighter. (There are some lighter 115's) It is also 60 lbs lighter than the Honda 115, and Honda 150.

[BrentB]

Aluminum or fiberglass?

Full floatation or partial so trim tabs can be installed?

[stevej]

I would have to agree with Bob that the 150 E-TEC would be a good fit.
Better to have the extra HP and throttle back than to not have if needed.

stevej

[Will-C]

A new four cylinder Yamaha 200 hp for the weight advantage. Lots of dealers.
D.D.

[thataway]

The Evinrude E-tec, in 200 hp is from 418 to 433 lbs--and from about 40 to 60 lbs lighter than the Yahama...but I would question putting 200 hp on that hull--
It might make it a rocket--but with experience where most of the 22's much over 30 knots become a bit unstable I would wonder about the wisdom of that much HP.

[Barry Rietz]

Hey Tom, have you seen this?

http://fairbanks.craigslist.org/boa/5574428069.html

[westward]

I don't have any technical basis for this, but 115HP seems right for your purpose. I think it would keep the boat nimble as originally designed. I would, tend towards the lightest one you can find. To me 90 HP might not be enough if heavily loaded, and 150-200 HP way too much/too heavy. Cool project by the way! Mike.

[Will-C]

I have been thinking of a similar project for my 25, remove splash well, raise transom, & add a bracket, that would give 2' more cockpit area.
A 200- 225 hp Yamaha would be a great match, I had a 115 Yamaha on my 91 22 cruiser it was not too much engine. Good luck & pay no attention to the Nay Sayers!!! [/quote]

Bob,
My suggestion about the 200 hp Yamaha's weight advantage was in response to the above.
D.D.

[jbdba01]

Found this thread - somewhat related...

[jennykatz]

We have a cc23 venture hull about 3000lb plus engine and goodies about another 900lb We sold our yamaha 115 and replaced it with a merc 115 CT This throws a 14by 17 pitch 3 bladed S/S prop.It's still pretty new so it get over 30-34 mph lightly loaded .With 4 big adults and full 60 gallons of gas and 20 gallons of water we could top out at 30 mph for a few minutes and go all day at 20 mph at 4000 rpm . This motor is awsome loads of power . we are getting over 4 mpg at cruise .In fact we have put on 12 hours on motor and burned 29 gallons of fuel.Giving us a 2.41 gallons an hour fuel burn with idle and slow speed mixed in with cruising speed .

[tomherrick]

Thanks to all for the input. With the exception of Barry; my wife saw the ad for that 27 and wonders why I'm going to all this effort... (That is one nice, nice boat though...)

Doubt I'll go anything over 150HP as this is a flat-iron version. I'll have to review posts about fuel economy between the 115 and 150, which is also a consideration.

Lots to learn and think about. I'm really a newbie at all this boat stuff.

[jennykatz]

BTW the merc 115 CT (command Thrust) has the same lower unit as a 150 merc so performance pretty much the same in slow speeds That why I decided to get the CT version of the merc 115 my Yamaha was at least 400rpm or more as the merc same speed .merc at 4000 -4200 rpm 20-22mph sweet spot for venture 23