Interested in installing a 15hp diesel into an Oday 25. Boat is not currently equipped with an inboard and would like some engineering info on hull requied modifications.
Inboard Diesel Installation
- Thread starter sunshinemartini
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Hi,
There's an awful lot to consider, but hull modifications aren't one of 'em. What you need to install are stringers, which are fore & aft supports for the engine mounts.
More importantly, if you don't have an inboard engine on the boat yet (using an outboard), you'll have to deal with building a stern tube which is the hole that the propeller shaft fits through.
Experience in inboard diesels in C25s indicates a severe lack of access to the engine, but even more importantly to the critical stuffing box. And the C25s have a quarterberth to starboard. As I recall, your O'Day 25 has a galley across the entire companionway, so I'm not sure how you'd gain access for quick oil checks and normal service. Correct me if I'm wrong.
You will also have to deal with fuel storage, and most likely a significant electrical system upgrade to support not only starting the diesel, which isn't really very much, but making the best use of the alternator output it will provide.
It's be interesting to know what your impetus for this modification has been.
There's an awful lot to consider, but hull modifications aren't one of 'em. What you need to install are stringers, which are fore & aft supports for the engine mounts.
More importantly, if you don't have an inboard engine on the boat yet (using an outboard), you'll have to deal with building a stern tube which is the hole that the propeller shaft fits through.
Experience in inboard diesels in C25s indicates a severe lack of access to the engine, but even more importantly to the critical stuffing box. And the C25s have a quarterberth to starboard. As I recall, your O'Day 25 has a galley across the entire companionway, so I'm not sure how you'd gain access for quick oil checks and normal service. Correct me if I'm wrong.
You will also have to deal with fuel storage, and most likely a significant electrical system upgrade to support not only starting the diesel, which isn't really very much, but making the best use of the alternator output it will provide.
It's be interesting to know what your impetus for this modification has been.
adding diesel to 25
There were a couple of 25's and 26's made with diesels. But spending that much to modifiy a boat that old is questionable.
If you have experience in installing engines in boats and have old but good diesel to install, maybe.
But there are many good old boats with engines in them at reasonable prices. Even if you had to change engines, the boat is already set up for the internal.
On the 25 you would probably check oil from cockpit access hatch and climb down next to engine. Fuel tank probably could go in locker where out board fuel tank goes.
Structurally as already pointed out is the need for additional support be it stringers, motor mounting pilars, stongbacks, or more. And engine oil catch basin.
But properly installing an inboard in a boat that old? Major surgery.
I agree, look for a boat with a diesel in it or get a good outboard.
Ed K
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There were a couple of 25's and 26's made with diesels. But spending that much to modifiy a boat that old is questionable.
If you have experience in installing engines in boats and have old but good diesel to install, maybe.
But there are many good old boats with engines in them at reasonable prices. Even if you had to change engines, the boat is already set up for the internal.
On the 25 you would probably check oil from cockpit access hatch and climb down next to engine. Fuel tank probably could go in locker where out board fuel tank goes.
Structurally as already pointed out is the need for additional support be it stringers, motor mounting pilars, stongbacks, or more. And engine oil catch basin.
But properly installing an inboard in a boat that old? Major surgery.
I agree, look for a boat with a diesel in it or get a good outboard.
Ed K
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Thank you for the input. I have modified many boats still not sure if I want to take this on. My resoning for considering this is that the boat fits our needs having a remote launch area without a lift within 30 miles. Since we sail primarily on Northern Lake Huron waters we would like the assurance of a second power source, Lake Huron can be fickle, I think hanging an additional outboard on the stern rail just doesn't look right. Also we are looking for extended cruising range now and not sure what the range of the 15 hp 2 cycle mercury bigfoot is with a 6 gallon fuel tank would be.
I bought an O'Day 25 last year that came with a small Yanmar 6.5 hp diesel and in the original brochure that it came with showed an inboard as an option. I haven't seen too many other diesel's on the 25, although I occasionally see them on the 26. It is nice not having to worry about the prop coming out of the water as a result of waves (Although an inboard would still have that problem in Ed's photo. Yikes!). I agree that unless you are really good at this stuff, this would be major surgery involving the electrical system as well as the motor installation. It might be better to just look for another boat. I saw some 26's with inboards listed on some other sites (the site had yacht in the title if I recall).
Note if they really wanted to sell them, they would post on this site. I sold my 222 within 3 weeks of posting on www.sailboatowners.com.
Dave
O'Day 25
Note if they really wanted to sell them, they would post on this site. I sold my 222 within 3 weeks of posting on www.sailboatowners.com.
Dave
O'Day 25
Unless you were repowering with another diesel inboard, I would not consider installing one in an O'Day 25; as others have suggested, you would be better off financially to sell your O'Day 25 and purchase boat with existing diesel. Now if you had a great Cape Dory you wanted to retain it might be worth the effort and expense, but we are talking about a Chevrolet of production boats.
I'd guess you get a gallon an hour fuel consumption.
There's nothing wrong with another outboard hanging off the rail. On our C25 when our regular 7.5 hp engine was in the shop, we used our 1.2 hp dinghy motor for a short period of time. Not a lot of oomph, but got us there and back at 1/2 speed.
Also sounds like you simply need more fuel storage. I assume you have a reliable basic outboard engine, and/or you know how to keep it working.
It's easy to learn your fuel consumption: put a gallon in the tank and see how long it runs at your normal cruising throttle level.
I think the quarter berth is on the port side, but neither here nor there. Probably finding a boat with a diesel inboard is the best advice, but if you re handy and have money to burn, go for it. You do have to make up motor bearers (someone called them stringers before) to fit the foot print of the engine you pick. So....pick the engine first, and then measure twice and build the motor bearers. White oak is a good wood choice as it is strong enough to tap threads into it for your motor mount bolts. But, white oak will also warp with weather, so you want to seal it up well or encapsulate it with fiberglass. You have to fiberglass it with roving anyway to make sure it is a very strong base for your engne. You need to run the shaft through the hull and so you need to figure the angle of the shaft from the engine to do that. The easiest way is to make a large hole for the shaft log and put your motor on the mounts on the bearers, connect and run the shaft through and then put the shaft log fiberglass tube (you can buy them made up) over the shaft and figure the lining up of that. Then when you know all components will work, have clearance, etc., you can fiberglass the shaft log into the hull with the engine pretty darned straight as you want it. You will need a cutlass bearing and the stuffing box (which attaches to the shaft log with a rubber hose and clamps and you also might need a strut (bronze with a cutlass bearing) to support he shaft outside the hull. Consider the right prop so you have the required hull clearance, which all will have to factor in to the angle of the inboard. So, there is some contemplation here.
You have to install the wiring harness which usually comes along with a new engine as well as the panel where you find the ignition and gauges and lights, etc. You also have to install a diesel fuel tank and you will have to consider that it has fuel lines to the engine and fuel return lines back to the engine. You have to measure the space beneath the cockpit where the engine will go and then make sure you get one to fit. And....you have to be able to find the dip stick, be able to pack the stuffing box packing, put antifreeze in the closed portion of the cooling system, install a water separator filter that is accessible, etc. I have done it successfully, but it is a lot of work, but fun for the right person. Do it for your own pleasure because you will never get the price you pay back when you sell the boat. At least an O'Day 25 boat.
You have to install the wiring harness which usually comes along with a new engine as well as the panel where you find the ignition and gauges and lights, etc. You also have to install a diesel fuel tank and you will have to consider that it has fuel lines to the engine and fuel return lines back to the engine. You have to measure the space beneath the cockpit where the engine will go and then make sure you get one to fit. And....you have to be able to find the dip stick, be able to pack the stuffing box packing, put antifreeze in the closed portion of the cooling system, install a water separator filter that is accessible, etc. I have done it successfully, but it is a lot of work, but fun for the right person. Do it for your own pleasure because you will never get the price you pay back when you sell the boat. At least an O'Day 25 boat.
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