Doodlebugs Latest Project... Engine at front of boat?

[waterworks]

 

 

What's wong with spinning the Seagull through 180 degrees?

The fact that its physically impossible ( with any standard mounting bracket known to man )

[MtB]

 

A third of a ton sitting above the centre of buoyancy and centre of gravity - what could possibly go wrong?

 

Doodlebug, will you be sitting this engine down in the bottom of the hull or up on the deck?

 

Richard

 

 

And another third of a ton for the alternator, engine beds and everything else I haven't thought of. (can hardly believe a CS weighs only 1/3 ton!)

 

Mr Bug plans fitting it up on the foredeck in full view in his OP IIRC, so that all seems fine...

 

jeez, these design engineers are a liability, innit!

[peterboat]

I have a rare earth magnet dc electric motor with 24 volt controller. I bought it years ago cost a fortune. I was going to use it for a hybrid system on my last boat but changed the boat before I had a chance to install it. You now have me thinking of doing it in this boat

[John V]

 

I would say that is a massive warning flag. Bet you John thought it would be simple when he started out

 

Richard

 

Oh Richard! You truly speak the truth.

 

It was an all electric 72' boat where someone else defined the size of the engine room and then filled it with a generator

I don't have a clue how much it would properly cost as most of the bits I wheeled and dealed for over several years.

If I had to do anything similar now it would be a diesel hydraulic.

but to be honest I would be looking for a more conventional answer

[Doodlebug]

I doubt the rest will come to that much.

 

Still it rules out the possibility of the hydraulic drive doesn't it?

Its frustrating that diesel weighs double that of a petrol engine.

 

Otherwise I could do it for less than 200kg.

[waterworks]

A 5/1 weighs 760 lb, without fuel or cooling tank.

 

You know they are gravity tank , or radiator cooled, and you would need to add a water pump ?

 

If that's not mounted on engine beds at bilge level then you will be steering a submarine in a very short time.

[RLWP]

How much does a cabin weigh?

 

Ahh - he's cutting off the cabin to compensate!

[John V]

a Mitsubishi 2 cyl engine 12Hp at just over 100 kilo

[RLWP]

Its frustrating that diesel weighs double that of a petrol engine.

 

Old ones do. Modern ones don't because of the commercial pressure to reduce the weight to fit them into motor cars and contractors plant and equipment

 

But you don't want a modern one

 

Richard

[Doodlebug]

 

Ahh - he's cutting off the cabin to compensate!

 

Actually you make a good point. The front section of the boat is tarp and has no steel in it.

 

I calculate that if we did have a steel top on the front section it would weigh 211kg so actually adding 300 doesn't seem too bad.

[RLWP]

a Mitsubishi 2 cyl engine 12Hp at just over 100 kilo

 

BORRRRIIIING!

 

Richard

 

[waterworks]

I doubt the rest will come to that much.

 

Still it rules out the possibility of the hydraulic drive doesn't it?

 

Its frustrating that diesel weighs double that of a petrol engine.

 

Otherwise I could do it for less than 200kg.

Yes but with the CS you have chosen the most elderly vintage Diesel there is, circa 1909, there are plenty of other lister and Petter engines that would do what you want at a fraction of the weight. LT1, AC1, SR, SW PJ, ect ect.

[RLWP]

Yes but with the CS you have chosen the most elderly vintage Diesel there is, circa 1909, there are plenty of other lister and Petter engines that would do what you want at a fraction of the weight. LT1, AC1, SR, SW PJ, ect ect.

 

Any idea what an Enfiled diesel would weigh?

 

Richard

[John V]

Oh don't worry, I have some ideas for wild systems.....How about a Humber barge driven by a Flettner rotor

[Delta9]

 

Ahh - he's cutting off the cabin to compensate!

I don't believe he has a cabin on the front

[ditchcrawler]

I do like a challenge!

 

 

I like the simplicity of the idea but worry about the sheer size of the engine needed. 5hp seemed pretty large though I may be able to stretch to 10. I did find the whole business of sourcing a pump and motor very confusing. Or would any hydrolic pump work?

 

 

 

Only issue here is having to change the steel work substantially though its still an idea worth looking at. Wonder how you stop the twisting of the prop over such a length.

My pump was ex refuse lorry, the motor second hand but unused. Volac positive displacement units.

[RLWP]

Oh don't worry, I have some ideas for wild systems.....How about a Humber barge driven by a Flettner rotor

 

[FadeToScarlet]

Oh don't worry, I have some ideas for wild systems.....How about a Humber barge driven by a Flettner rotor

Hotchkiss cones.

[waterworks]

 

Any idea what an Enfiled diesel would weigh?

 

Richard

Enough to sink to the bottom of the cut when you find out there are no spares available.

Hotchkiss cones.

Raspberry ripple ?

 

 

Reference hydraulic drives, the pump and motor have to be specifically sized for the engine hp, and sized in relation to each other for the correct reduction ratio. You can't just use any old units from the scrappy.

Edited March 6, 2016 by waterworks

[RLWP]

Enough to sink to the bottom of the cut when you find out there are no spares available.

 

There seem to be complete engines available for not too much money, so that might not be a problem

 

I rebuilt an Enfield gearbox last year - it was a very nice piece of engineering. A bit OTT perhaps for a boat

 

Richard

[waterworks]

Have you seen my avatar picture ?

 

Must be something in there ?

[zenataomm]

Ok cool. I know this is asking for a guess but how many hp do you think are needed to keep a shortish boat moving at tickover?

 

I knew enjineerin' was was based on exact science, however I never realised you had to be so precise as that!

[bizzard]

The tried and tested, simple Phutt phutt tube could be the answer.

[Scholar Gypsy]

This video (which featured in a C&RT newsletter published on Friday) describes a boat (based in Cambridge) which runs its electric motor from batteries, charged entirely from the solar panels.

 

No sun, no boating: but they get a decent daily range

[Phil Ambrose]

The fact that its physically impossible ( with any standard mounting bracket known to man )

Quote a common method of getting reverse, even the little Honda 2.3 uses this method, I had one once also one or two other O/Bs which did the same, this method is usually reserved for low HP models, once you get to 4hp there is usually a reverse fitted.

Phil

This video (which featured in a C&RT newsletter published on Friday) describes a boat (based in Cambridge) which runs its electric motor from batteries, charged entirely from the solar panels.

 

No sun, no boating: but they get a decent daily range

The trip boat "Ra" run by the Broads Authority on Barton Broad is totally run by it's PV array.

Phil