Motor Conversion?

sailaway78 · Dec 17, 2008

Engine choices

IMHO On an older 24 footer I think the cost of purchasing and installing an inboard engine would be much more than the value of the boat. Not only will you have to purchase an engine, and a tranny, but also a prop shaft, prop, and strut. Plus make a hole for the shaft out of the boat, a shaft seal, or packing for it, and make everything line up. The engine alone will probably cost more than a new outboard of comparable size. I realize that sometimes what one wants over rides everything else, so if you decide to go ahead and go inboard, your best bet would probably be a one lung Yanmar. These were made with several horsepower ratings. I think the lowest was 8 HP and the largest in the neighborhood of 12HP.
Whatever your decision, the best of luck to you.

David in Sandusky · Dec 17, 2008

Possible: Yes. The big issues will be the design and glass work to accommodate the shaft, and the cost.
Recommended: Hmmm... How about telling us why you want an inboard?
Acceptable: sure. But you will spend a lot of money without adding much at all to the value of your boat.
Knowing a little bit about your sailing plans, and the waters you will sail will help, too.

But an outboard is the most common solution for a 24 footer, and you may not need 10 hp. A smaller outboard engine could be light on your stern, and very easy to handle.

A motor sales operation who know sailboats should be able to compute the performance you could expect out of different power levels.

Best of luck with your new boat!

Ross · Dec 17, 2008

There is a wide range of single cylinder diesels in the range of 5-10 hp. But as was stated the cost will be substantial. I repowered my boat when I rebuilt her and the engine(Volvo 2001 model 10 hp) cost me $4500 with the transmission in 1995. add to that a new shaft $120,new PSS seal $195 , plus coupling, drive saver, fuel filters, fuel lines, filler port, vent tubing, fuel tank, fuel tank mounts, batteries, battery boxes, battery cables, control cables, control panel, exhaust hose, mufflers, exhaust port through hull, Raw water filter, new engine beds and the cost came up to about $6500 total. And I have the skill and the tools to do all of the labor for the installation.

higgs · Dec 17, 2008

Forget it.
The boat is not worth the infusion of $.

A single cylinder anything is not an engine that will give you a comfortable ride. A four stroke 9.9 will be much smoother. A two stroke 9.9 will be smoother than a single cylinder inboard.

I am one who feels an outboard should avoided, but in your case, I think it is the way to go.

Steve Dion · Dec 17, 2008

The rule of thumb for an inboard engine conversion is 1 hp/500 lbs.

I doubt that it is worth the expense. Take that money plus the sail of the current boat and invest it in a boat with an inboard engine.

sailingdog · Dec 18, 2008

The real problem is that you'll be putting a lot of money into converting the boat into an inboard. After doing so, you'll have a boat with far less interior room than its sister ships, that is far less marketable than its sister ships in the event you decide to sell it. The engine and transmission alone are likely to cost almost as much as a C24 is worth in good condition, not counting the cost of the glasswork, the prop shaft, cutless bearing, packing gland, and propellor.

Also, an inboard is often more difficult to maintain and more expensive to maintain. An outboard, especially in the size range you're talking about can often be dismounted and taken in to the local shop for service and repair. That isn't possible with an inboard.

I don't think you've really properly thought this through. The amount of space an inboard engine takes up is far greater than that of just the engine. You also have to have a raw water through-hull, water strainer, prop shaft, etc...

Ross · Dec 18, 2008

Stormer, over here on the Chesapeake Bay the skipjacks have a yawl boat that they use for pushing them in and out of harbors and for when the wind doesn't blow.
The yawlboat is a small boat with a big engine and propellor that is lashed to the stern of the skipjack with her bows in a socket made for pushing and steered with a pair of tackles from each quarter rail. Of course the skipjacks are somewhat larger than your boat so it probably wouldn't be a convenient way.

BobM · Dec 19, 2008

Stormer,

Have you considered electric? It is certainly feasible for a boat that size. Again, it likely woudn't be as cheap as an outboard. I found this interesting review article by Jim Kerr online, but can't vouch for its veracity.

http://www.mindspring.com/~jimkerr1/sebc&t.htm

http://re-e-power.com/ sells complete solutions at about $3000 for a 24 footer. Again, I have no experience with this set up, but it is interesting.

Ron20324 · Dec 19, 2008

Or maybe a saildrive?

Ross · Dec 19, 2008

I have often thought that if I were building a boat I would ballast with batteries and power with an electric motor and run a diesel generator for battery charging or for long distance motoring. And if I had a lot of money I could afford to try that. But I ain't made of money and someone else will have to try it.

There have been more different propulsion schemes tried then any one person could dream up in a lifetime but we keep coming back to an engine, transmission, shaft , stuffing box and propeller. Perhaps because it is the best balance between cost and efficiency.