Engine swap

[lance gasman]

Hi does anyone know if you can fit an engine that has an lpg conversion . Will be done to gas regs but looked a d can't see any info on it . Cheers 

[Jen-in-Wellies]

Welcome to the forum. Section 2.17 of the boat safety scheme requirements for private vessels covers LPG driven engines, so it has been done. Worth a peruse. They will want to use an examiner who knows how to inspect to the appropriate ISO reg BS EN ISO 15609.

https://www.boatsafetyscheme.org/requirements-examinations-certification/private-boat-requirements/

 

[BoatinglifeupNorth]

I kew of a guy that wanted to fit a gas fuelled generator into his engine bay to charge the batteries. The big problem was there was nowhere for the gas to vent in the event of a leak, with gas being heavier then air and the engine compartment being mainly under the water, it would of just filled the engine bay. Even the BSS/gas boat safe inspector couldn’t really find a solution how to vent it, so he just got a diesel generator, as no one came up with a solution.

[David Mack]

How are you going to store and refuel your gas? Bottled gas will be expensive for your main propulsion fuel, and canalside boatyards don't tend to have lpg pumps. If you are going to be reliant on Calor bulk deliveries as some households do, you are probably going to need a very large (for a boat) tank, to meet minimum delivery volume requirements.

[lance gasman]

Can get lpg for a good price.  With the way diesel is rising and the stigma around it I am exploring other ways of fueling music boat . Have already got an engine I can use and fitting I can do myself . Dont want ro go down the expense of an electric system . And to be honest like the sound of an engine 

[ditchcrawler]

I am sure there use to be a gas engined hire boat in the Rugby area many years ago, it may even have been Rose, but it was a long time ago. 

[Alan de Enfield]

8 minutes ago, lance gasman said:

Can get lpg for a good price.  With the way diesel is rising and the stigma around it I am exploring other ways of fueling music boat . Have already got an engine I can use and fitting I can do myself . Dont want ro go down the expense of an electric system . And to be honest like the sound of an engine 

 

What age is the boat ?

[MtB]

13 minutes ago, lance gasman said:

Can get lpg for a good price.

 

That's not the issue. How are you going to store it in big enough amounts to use as propulsion fuel.

 

You intend using fork lift bottles would be my guess.

 

 

[Tony Brooks]

1 hour ago, ditchcrawler said:

I am sure there use to be a gas engined hire boat in the Rugby area many years ago, it may even have been Rose, but it was a long time ago. 

 

Was the not Firefly, the steam hire boat. I am sure that was gas fired when being hired.

[BoatinglifeupNorth]

 As I mentioned, how will it be safe(BSS)

you have a LPG engine with no drains out of a confined space as it’s under water. say you have a gas leak, it will fill the engine bay with flammable gas, where you have electrical components maybe batteries all with a potential to ignite that gas, hows it going to work?

 These were the points my friend had with putting a gas run generator in the engine bay, even though the gas bottles were outside. No-one would put their job on the line and give any ideas how to  overcome the gas leak problem, so a diesel generator installed.

Edited September 21, 2023 by BoatinglifeupNorth

[ditchcrawler]

51 minutes ago, Tony Brooks said:

 

Was the not Firefly, the steam hire boat. I am sure that was gas fired when being hired.

Not the one I was thinking of, I did see that, but this was an IC engine

[David Mack]

2 hours ago, ditchcrawler said:

I am sure there use to be a gas engined hire boat in the Rugby area many years ago, it may even have been Rose, but it was a long time ago. 

I seem to recall one on the Leeds & Liverpool too. Probably back in the 70s or 80s.

[Francis Herne]

57 minutes ago, BoatinglifeupNorth said:

 As I mentioned, how will it be safe(BSS)

you have a LPG engine with no drains out of a confined space as it’s under water. say you have a gas leak, it will fill the engine bay with flammable gas, where you have electrical components maybe batteries all with a potential to ignite that gas, hows it going to work?

The engine could be mounted in a sealed bay above the waterline with drains, like a very large gas locker.

 

Hydraulic transmission probably easiest as a provably gas-tight shaft seal is unlikely.

 

This all seems impractical to retrofit into an existing boat - I'm sure the cost would exceed any possible saving on fuel.

Edited September 21, 2023 by Francis Herne

[BoatinglifeupNorth]

25 minutes ago, Francis Herne said:

The engine could be mounted in a sealed bay above the waterline with drains, like a very large gas locker.

 

Hydraulic transmission probably easiest as a provably gas-tight shaft seal is unlikely.

 

This all seems impractical to retrofit into an existing boat - I'm sure the cost would exceed any possible saving on fuel.

So the engine would be basically sitting on the back deck or somewhere outside the cabin?

 Why do people want to reinvent the wheel? If LPG Gas was the way ahead why hasn’t it become an alternative to the diesel engine, were LPG conversions being offered when the cars were getting them done? I would say it has too much potential to be dangerous.

Edited September 21, 2023 by BoatinglifeupNorth

[Francis Herne]

My own pet hypothetical idea is to put a wood gasifier in a boat and run the engine off that.

 

They consume woodchip, twigs etc. so would be effectively free to run.

Trialled in cars but proved impractical due to weight, volume and the gasifier plant not being able to cover the very wide power range needed. A narrowboat application would suffer much less from those.

 

As with LPG, the problem is explosive gas and the packaging difficulties in mitigating that.

[MtB]

2 hours ago, BoatinglifeupNorth said:

As I mentioned, how will it be safe(BSS)

you have a LPG engine with no drains out of a confined space as it’s under water. say you have a gas leak, it will fill the engine bay with flammable gas, where you have electrical components maybe batteries all with a potential to ignite that gas, hows it going to work?

 

It could work in exactly the same way as petrol engines work in a boat. The risks are virtually identical. Petrol vapour and LPG have similar characteristics and behave in much the same way. Bilge blowers are used on petrol engines AIUI below the water line. Same could be done with LPG engines I reckon. 

 

 

[David Mack]

3 hours ago, BoatinglifeupNorth said:

If LPG Gas was the way ahead why hasn’t it become an alternative to the diesel engine, were LPG conversions being offered when the cars were getting them done?

Back in the 80s I knew a bloke who had done just that. He had a splendid teak and mahogany centre cockpit cruiser, about 30 ft long and 8 or 9 ft beam, which he kept on the Thames, but occasionally travelled onto the canals in London. It was fitted with some thirsty petrol engine, mounted amidships below the cockpit floor. He had converted it to run on lpg with a couple of 47kg Calor propane cylinders just standing in the corner of the cockpit. You could tell which one was in use as the bottom half of the cylinder was covered in frost! He must have got through some gas, but he reckoned it was still a lot cheaper than using petrol.

[john.k]

I was talking to someone about this just this week............he has access to the LPG tanks from scrapped cars ,which normally just pile up in salvage yards,and are allowed to 'leak' away before the tanks can be crushed or shredded...........obviously the danger point is decanting the liquid from the car tank into his tank ........all probably illegal .........but with gas being something like $1/litre ,worth a bit of risk.

[Jen-in-Wellies]

We don't know what sort of boat, or engine @lance gasman intends to convert. A petrol outboard on a GRP cruiser is going to need different considerations from a petrol inboard on a GRP cruiser and different again from an inboard diesel in a steel narrowboat.

[Onewheeler]

12 hours ago, Tony Brooks said:

 

Was the not Firefly, the steam hire boat. I am sure that was gas fired when being hired.

The steam Firefly was gas fuelled, but converted in the nineties to an air-cooled Lister diesel.

 

[Bee]

I think the expense in storage, bilge blowers, gas tight alternators, starter, electrics etc and fittings might add up to be a problem and I would be very wary of buying a second hand gas fuelled boat, happy with stuff that worries other people, overplating etc. but gas???????

[magnetman]

Ir would make sense for an outboard motor. 

 

If the idea was to be home filling small gas bottles maybe 3.9 or 6kg from a large LPG tank one could have one each side of the motor on the back of the boat. 

 

There was an LPG powered outboard motor brand not sure if they are still going but I recall it being at the Boat Show a number of yars ago. 

 

 

 

LEHR was the brand name..

 

 

google search 

 

"What happened to Lehr outboards?

 

 

Lehr was bought by another company who is not currently making outboards and not supporting the old ones. West Marine has dropped them as a vendor but may be able to help you if you call them. Tohatsu is also been marketing one."

------

 

 

Of course it is very common to see LPG generators so presumably a Honda outboard would be easy enough to convert for someone with a bit of know how. 

 

 

The LEHR outboards had their own fuel cannisters which was a bit interesting I don't know if they were manually refillable or exchanges. If the latter then it isn't surprising if the idea failed. 

 

 

Looking at it the bigger ones ran on remote tanks..

[Tractor]

Firefly had a large white gas tank fitted across the bow, forward of the fwd access doors. Leakage could be spilled overboard in the usual way for LPG.

 

[john.k]

There is a catch with gas conversions.....the motor must be in good condition,otherwise the gas leaks from the cylinders into the sump,and will wreck the sump and rocker cover on motors where they are pressed tin.

[cuthound]

16 hours ago, Francis Herne said:

My own pet hypothetical idea is to put a wood gasifier in a boat and run the engine off that.

 

They consume woodchip, twigs etc. so would be effectively free to run.

Trialled in cars but proved impractical due to weight, volume and the gasifier plant not being able to cover the very wide power range needed. A narrowboat application would suffer much less from those.

 

As with LPG, the problem is explosive gas and the packaging difficulties in mitigating that.

 

I put eight syn gas powered Stirling generators in as part of two projects, 4 generators per site.. The generators were only rated at 4kW each yet the wood chip gasifier was two stories high. The container for the woodchip lasted a week and took two tipper trucks to fill it. A bit impractical for a boat.

Edited September 22, 2023 by cuthound