Why don't people use these engines in boats?

[LONG_KEELER]

I still think that way to go for a dead diesel in a classic plastic is an outboard in a well. What have you to lose ?

Pick your spot, cut a rectangular hole, beef it up and start building upwards to the required height.

Loads of conversions on the web. Most of the old petrol inboards were 2 stroke with not the greatest mpg. 4 strokes quieter , good mpg and
little smoke. Cover up the top required though to offset the loss of mobile phones, vhf's , screwdrivers etc...

How about a diesel outboard Diesel outboard engine, China diesel outboard engine, diesel outboard engine Manufacturers, China diesel outboard engine catalog

 

[Stemar]

While I accept that petrol is inherently more dangerous than diesel, a properly installed fuel system - nothing fancy, just a fixed tank, a filler that ensures spills go over the side and a vent to the outside and a spark-free fan to clear any vapour from the engine compartment would be as safe - probably safer - than most of the gas installations we live with quite happily.

To me, the main reason for a diesel is economy. All the other advantages - no worries about ignition systems in soggy bilges, etc, can be overcome. This is the 2020s, not the 1920s. We can make things as waterproof as we like now.

 

[rotrax]

I still think that way to go for a dead diesel in a classic plastic is an outboard in a well. What have you to lose ?

Pick your spot, cut a rectangular hole, beef it up and start building upwards to the required height.

Loads of conversions on the web. Most of the old petrol inboards were 2 stroke with not the greatest mpg. 4 strokes quieter , good mpg and
little smoke. Cover up the top required though to offset the loss of mobile phones, vhf's , screwdrivers etc...

How about a diesel outboard Diesel outboard engine, China diesel outboard engine, diesel outboard engine Manufacturers, China diesel outboard engine catalog

There were some diesel outboards in your link, but most of the smaller ones were in fact petrol when you got into the small print.

An interesting link. Thank you.

 

[STATUE]

Talking about the older small boats where the diesel has died and replacement far in excess of boats value. Hook up to existing prop shaft etc. Would be better than putting an outboard on the back.

13 HP 9.56 kW Petrol Engine (25 mm Shaft, Low Oil Protection, Air-cooled Singel Cylinder 4-stroke Engine, Recoil Start) - GG1-ER389-25

Obviously some engineering required e.g. for exhaust and gearbox but a base 4 stroke unit for that price? Commodity spare parts available...what's not too like?

Bring back the Stuart Turner 1.5 hp - did wonders for my state of high anxiety !

 

[rotrax]

Not much wrong with the engines, useually the fuel or magneto with issues.

In a previous life I would collect and deliver Lucas and Wipac magnetos to the Henley works after overhaul.

 

[LittleSister]

It is easier to find diesel than petrol when away cruising.

Indeed. I'd forgotten the miles trudged or taxied (and the sailing time lost) in search of petrol stations to feed my thirsty Yamaha 8hp 2-stroke outboard when cruising the West Country and Brittany years ago. Always uphill, usually a good distance from the harbour, and not always open!

Would not have been a problem at all for a local boat and day-sailing, though

 

[rgarside]

I think it would need an entirely different gearbox to make it work. I'm not saying it's impossible, I just think that it would end up being much harder than you suggest. Just for starters, to get that 13HP, you're probably emitting at least that much heat equivalent - in other words, around 10kw of heat. So, you're going to need an effective blower system to keep cool air round the engine and removing hot air from the enclosed space below decks. Without it, the engine will over-heat and the below decks will become unliveable. The exhaust is dry, so it's at a very high temperature - well over 100 degrees C, probably a lot over; certainly enough to melt solder. So, the exhaust will have to be rerouted and made safe, somehow. The existing exhaust won't do - the cooling water keeps its temperature down, so it can be routed safely through lockers etc. The existing gearbox is designed for the power curve of a particular engine; it almost certainly won't be suitable for an engine which, by its nature, will have a very different power curve.

Probably more heat than that - typical thermal efficiency around 30% so more like 20kW of heat.

 

[Laminar Flow]

Probably more heat than that - typical thermal efficiency around 30% so more like 20kW of heat.

Old Listers were aircooled, as well as some old DAF. They require proper venting of course, but both were fairly common and yes, on boats as well. There was a practicable limit as HP increased; I remember it was in the neighbourhood of around 40 HP. The dry exhaust was no problem at all, certainly not on my Lister. Aircooling also takes the pain out of a number of corrosion issues.

Once upon a time, all small engines ran on pertrol, unless they were steam driven.

Any number of MOBOs use large V8 gas engines, they seem to only explode in the movies. A boat neighbour of mine had twin V8s in his 50' Trojan; the only thing that would seriously put me off was his mind-numbing fuel bill and the lack of sails.

 

[dgadee]

Bring back the Stuart Turner 1.5 hp - did wonders for my state of high anxiety !

Did they do a 5hp one? That would have been in my first boat. Quiet but always stopped whenever I entered a harbour.