install in-board,shaft etc

[noname]

can anyone offer ideas to set position of engine,setting bearers and set up of prop shaft and drilling hole through hull,boat is islander 23,has small stub on hull where shaft exits advice on parts e.g.cutlass bearing etc,only thing i m sure about is boat s got to be out of water!!!

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[Avocet]

Spend some time making as accurate a scale drawing of the hull as you can - at least the bit with the engine and stern tube in it!

Choose an engine & gearbox based on the sort of power which that boat and hull form are likely to need (10-15hp should be plenty for a 23 footer) Remember to err on the generous side to account for transmission losses and head winds, fouled hull, etc but don't go mad or you'll never get the engine working hard enough!

When you select an engine ask for installation drawings. I guess most new engines will come with outline scale drawings and dimensions. Make a cardboard template full-size and offer this up to your drawing.. To be honest, it won't be that much more work to make the template 3-d to offer into your hull(OK, forget about details, just hald a dozen blocks will do. Err on the large side.

Once you've done this you will get a pretty good idea of where it has to go and where the mountings will be. See how this suits your boat. If it doesn't, choose another engine.

I think it's worth adding all the extras in one go (e.g. tappings for a calorifier if you're going to have one, engine bay fire extinguisher(s), sound deadening panels, heat exchanger (if not raw water cooled) and so on because it can be hard to do this retrospectively.

Remember the engine manufacturer might have installation requirements too (like maximum permitted inclination in side-view). Also allow space for oil and filter changes.

Good luck!

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[colvic]

Has there been an engine instaled before?

Phil

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[charles_reed]

Starting from scratch, with no previous knowledge, - I don't know whether to take my hat off to you or suggest you visit your GP.
What you're proposing cannot be covered by a simple bit of advice over a BB but needs a good engineering background and lots of drawings.

I'd suggest as simple an engine as possible - preferably a diesel.

If you're buying new look at the 1GM10 Yanmar, if you're going to buy second hand I'd suggest the following people:

1. Don Evans Diesel Engines
Broadheath
Tenbury Wells, WR15 8QX
tel 01886 853279

2. John Skues
Cellar Garage Marine
Penhallow
Helston
tel 01326 280214

3. For bits of sterngear and props, he supplies most of the professionals and doesn't suffer DIY fools gladly:
Les Hill
Lake Engineering
Unit 5, Stepnall Reach
BlandfordRd. Hamworthy PH16 5BW
tel 01202 621631

Good luck


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[jleaworthy]

Could I suggest that most of your questions would be answered if you were to buy a suitable book on the subject? Perhaps you could consider "Build Your Own Boat" by Ian Nicholson (George Allen & Unwin); "From a Fibreglass Hull"by Michael Collins (Adlard Coles); "Home Boat Completion" by David Everett (Hale), and I'm sure there are plenty more. Each of the three named have extensive sections on engine selection, engine installation, shaping and fastening of engine beds, installation of stern tubes and drive shafts, fitting fuel and exhaust systems etc etc.
Well worth a modest investment in time amd money. Good luck. If you can't find any of the above I'll lend you mine.

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[snowleopard]

strongly recommend you plan for a hull-mounted flexible thrust bearing . this will prevent the thrust of the prop from acting on the gearbox and from there the engine mounts. that means you have few worries about alignment, less noise and less bother with stern gland leaks.

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[pete]

I did the same as you propose starting from scratch
I cut a piece of block board about 28mm thick to the footprint size of the engine including flexable mounts to this I fixed two upright boards front profile of engine and profile at flexi drive from gearbox they were mounted to the baseboard in the corect positionswith brackets, every thing was cut very basicaly but not under size then I measured and marked the exact output shaft position on rear board and drilled a 1 inch hole and inserted a length of 1 inch straight dowel through this hole from the back making sure this dowel is centered on the front profile board you have to copy the shaft angle from the engine drill through the front board and slide dowel through use this as a template to decide position, check clearances and fabricate engine bearers once happy with this bolt template to bearers slide dowel back until it touches hull and make the exit hole obviously loads of checking along the way, this system worked well for me but expect to shim under engine mounts to get exact alignment.

good luck

Pete

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