Sterndrive conversion

PCUK

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Surface drives cost vastly more than an outboard or out drive and would be totally unsuitable for a seaworker. Designed for boats over 50 knots. Your idea is unworkable to put it bluntly! Not being rude by the way, stick to conventional thinking and you won't waste your money. Outdrives are often advertised at reasonable prices. I've bought them in the past and had no problems. Where are you based?
 

Dino

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What about something like this Thames police launch, ARISAIG - Ad 109196
Would probably need to live on a mooring but it would tick a lot of boxes for you. I’ve seen one that was very well refurbed and it was a lovely boat.
You could rebuild or replace the engine and refit the rest of the boat. It’s shaft drive too
 

Dieselboatman

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Yeah will stick to looking for an inboard project

I did see that Thames police launch but cant afford mooring costs in cornwall!
Shame as would be a perfect boat
 

Dino

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If you’re looking for something that you can tow home after each use and that you can launch and recover easily, I would stick to 18-20ft with an outboard engine. Anything with a diesel is going to be very big and heavy to tow and launch.
 

25931

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Hello all

I am a diesel mechanic by trade and a hobby fabricator in my spare time

I am looking at getting a project boat, but dont want an outboard

Ideally inboard but sterndrive possible

However what puts me off sterndrive (and outboards) is the cost of them

Seen some inboard boats in size I would like (18~22ft)

I rather like the colvic 20 and seaworkers personally


However, I see an awful lot of sterndrive boats available (either with no sterndrive or an old knackered one still fitted)


Would it be possible to fabricate a plate or even a box to fit where the stern drive would, and then simply have a standard inboard gearbox and a stern gland instead?
With a prop behind the boat instead of under, and then just fabricate a rear mounted rudder?

Would this work? Any issues with doing this?
Just wondered why all of the inboard boats I have seen have prop underneath and not at back (in similar location then to a sterndrive or outboard)

Any advice/assistance would be great!
I am probably talking nonsense but what about jet drive ?
 

Dieselboatman

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Yeah it's just cost of outboard units that worries me

I'm not too worried about weight of boat on trailer, I have a 2006 Toyota Hilux so towing weight is fine, and I'm used to big trailers (big farm trailers etc)

I know it would be heavier to launch but shouldn't be too bad should it?
I've seen people launching some big boats (25ft plus with twin stern drives or 3/4 big outboards)

I want to stay around the 18/20ft if possible with a single inboard diesel (1.8D is less than 200kg lump, 2.5di is around 250kg)

Will just have to keep eyes peeled for something I think!

Jet drive is something that's always tempted me (soft spot for the old PBRs I think!)
 

gordmac

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I think the boats you mention are semi displacement and should be inboard diesel anyway. Fitting an inboard diesel to a small planing Hull could be difficult, the crank centre line will probably be above the waterline requiring an angled installation, will the engine be ok at an angle? The engine etc will take up a fair bit of deck space.
Check your Hilux towing limit, from memory it won't be much over 2 ton, not hard to exceed with a diesel engined boat on a trailer.
 

omega2

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Hello all

I am a diesel mechanic by trade and a hobby fabricator in my spare time

I am looking at getting a project boat, but dont want an outboard

Ideally inboard but sterndrive possible

However what puts me off sterndrive (and outboards) is the cost of them

Seen some inboard boats in size I would like (18~22ft)

I rather like the colvic 20 and seaworkers personally


However, I see an awful lot of sterndrive boats available (either with no sterndrive or an old knackered one still fitted)


Would it be possible to fabricate a plate or even a box to fit where the stern drive would, and then simply have a standard inboard gearbox and a stern gland instead?
With a prop behind the boat instead of under, and then just fabricate a rear mounted rudder?

Would this work? Any issues with doing this?
Just wondered why all of the inboard boats I have seen have prop underneath and not at back (in similar location then to a sterndrive or outboard)

Any advice/assistance would be great!
1585983376468.png1585983376468.png
 

Dieselboatman

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That's an Interesting piece of kit!
Will have a look as been offered an 18ft boat with an old knackered sterndrive and a seized ford pinto engine.....

That coupled to a smaller diesel (1.8D ford for example would keep weight down)

Hilux is rated to 2250kg I think towing capacity
 
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