New inboard engine installation

AlistairM

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I was talking recently with someone who had just purchased and had fitted a new marine engine. I didn't think to ask at the time (and bearing in mind I know nothing of such things), but I was wondering how do you go about installing such a large and "solid" item in to the relatively small allocated section of the boat?

Just musing on my behalf but if anyone can provide a solution or at least let me know how they have done it before, I would be interested.

Thanks

Alistair
 
Not sure what your question is. If the boat already has an engine and you are replacing it the basic space is already there as is the location of the main fixed point, the shaft. You then build whatever is necessary to fit your new engine in place of the old one to mate up with the shaft, then install all the ancilliaries - exhaust, controls etc.

If there is no engine more is needed - installing stern tube and shaft and building engine beds using the detail installation drawings provided by the engine manufacturer.

For all but the very smallest engine you need access to some sort of lifting equipment to get the engine into the boat.

Nothing particularly difficult about the process if you can read instructions and drawings plus basic mechanical skills.
 
I'm not really sure what the question is here. You lift the old one out, you lower the new one in. Some people have used a tackle from the boom, some a full-on mobile crane, and others everything in between from scaffolding to a forklift. In most boats it can't drop vertically to its final position, so you either man-handle it backwards while still hanging from the hoist, or lower it onto the cabin sole and slide it backwards on some bits of wood. How much of the handling needs to be mechanical and how much can be simple manpower will depend on the size of the engine.

Pete
 
When I fitted my Volvo 2002's. they are only 2 cylinder engines, I got my mate, rugby player, brick s*it house type, to just lift them in. He made it look easy.:encouragement:
 
When I fitted my Volvo 2002's. they are only 2 cylinder engines, I got my mate, rugby player, brick s*it house type, to just lift them in. He made it look easy.:encouragement:

We used an electric hoist on a scaffold "goalpost" over the boat to lift Kindred Spirit's 2GM20 out for overhaul and back in again. But to get it in and out of my car (VW Polo) the boot lid was in the way of the winch wire, so two of us had to do it by hand.

Pete
 
From a DIY point of view?

Access can vary from easy like my last Macwester, open hatch in cockpit floor. undo, attach to boom used as crane, lower to hard standing.

To difficult, requiring surgery to the boat's structure, e.g. when the engine was installed before the topsides were fitted.

People will now be thinking about planks (or skateboards) to slide the engine/box forward into the saloon. Also taking off as many heavy ancillaries as they can reach

If a little marine engine, quite do-able. If a car or truck derived unit, difficult.

I've a pic somewhere of a MoD double diagonal launch where the process of removing the engine was simplified by chainsawing a 6' square hole on the side of the hull and using a fork lift. (Made a right mess of the paint though...)
 
I've a pic somewhere of a MoD double diagonal launch where the process of removing the engine was simplified by chainsawing a 6' square hole on the side of the hull and using a fork lift. (Made a right mess of the paint though...)

Quite a common approach on steel fishing boats as well, I believe.

Looking at Stavros's plans (framed on the bulkhead) there is a route for vertical engine extraction through a series of bolted-down plates in the accommodation deck, the captain's cabin, and the bridge. Might need some minor dismantling of steel and timber on the way even once the plates are opened!

Pete
 
Quite a common approach on steel fishing boats as well, I believe.

Looking at Stavros's plans (framed on the bulkhead) there is a route for vertical engine extraction through a series of bolted-down plates in the accommodation deck, the captain's cabin, and the bridge. Might need some minor dismantling of steel and timber on the way even once the plates are opened!

Pete

Three weeks ago I was doing the same thing on the Eyemouth Trent class lifeboat, lots of external SS bolts on complex GRP mouldings above where the mains must be. (You can tell I was stuck there 4 days...)

N
 
The way my old dutch steel boat had a change of engine was interesting. Cut round engine, lift boat, remove engine. Put new engine on old modified bedplate, place under boat, lower boat and weld. Simples!
 
For a single-cylinder diesel on a 20-ft Vivacity I used a 3x3 piece of timber across the companionway and the mainsheet as lifting tackle. This was a 'new' installation. The shaft was passed through a slot that I had cut in the bottom and the outer end was supported by a P-bracket. I had previously made a stern tube by wrapping fibreglass round a 38mm (?) plastic drain pipe and had threaded this over the shaft. Once the engine and the P-bracket were in line (shaft could be turned using finger power and no binding) I centred the tube around the shaft and then glassed it in place.

For a three-cylinder Lombardini to replace an old Volvo on a Westerly Centaur I first bolted the bearers (80 x 80 x 10mm angle) to existing upright 'walls'. These angles were pre-drilled to take the engine mounts. I then built temporary wooden skid-ways in line with the bearing surface. Engine was lowered onto the skidways with the mountings already bolted to the engine brackets. Engine was then slid into position and the bolts for the mountings simply dropped through the holes. Alignment with the existing shaft was 'pre-engineered' using an accurate template board (that also incorporated a representation of the drive-shaft centreline) and the shaft coupling (centred in the stern tube). Final alignment was done as usual and was minimal.
 
Apologies for not being clearer. On the boat in question, I couldnt work out how they actually got it in. From what im getting, the approach is to assemble it in situ, if there is no direct access, such as a hatch in the cockpit floor or something similar
 
Most boats have access through the hatch and then slid into the engine space. Some have removable panels or cockpit floors, but the odd (badly designed) boat has the deck moulding put on after the engine is installed so you have to cut bits out for access.
 
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