LPG.....

[Supermalc]

This hasn't been discussed one here.....has it? Well not lately unless I've totally missed it.

 

Now that boats will have to use white (obscenely taxed by our country) diesel in a year or two, what are the ACTUAL rules (laws) at present, as to running on LPG. (I'm sure a search of car/truck forums could soon find the answer) But I bet there are as many 'experts' offering their opinion on them, as much as any.

 

I didn't like the thought of running a car on it, do to the BOOM factor. Just think it could be worse on a boat.

 

But now many cars/buses/taxes have convertions I guess they have become safer. A bilge blower running in the engine compartment venting outside would be a must though.

Edited January 12, 2007 by Supermalc

[Theo]

This hasn't been discussed one here.....has it? Well not lately unless I've totally missed it.

 

Now that boats will have to use white (obscenely taxed by our country) diesel in a year or two, what are the ACTUAL rules (laws) at present, as to running on LPG. (I'm sure a search of car/truck forums could soon find the answer) But I bet there are as many 'experts' offering their opinion on them, as much as any.

 

I didn't like the thought of running a car on it, do to the BOOM factor. Just think it could be worse on a boat.

 

Someone I know was telling me recently, that years ago they ran a van on it. Just simply had a bottle in the cab with a pipe going into the top of the carb. All they did was to turn the gas on and start it up. They regulated it to run flat out by turning the gas. I suppose when they were stationary, any unused gas would just drop to the ground, being heavier than air, and the engine bay being open. Maybe they just blipped the throttle occasionally, like you used to have to do with tuned engines, before computers operated all the variable required to run an engine efficiently, at low speed.

 

So on a boat, as long as you had 'bilge blower' in the engine bay, venting outside, I suppose it should be safe.

 

 

I'm not at all convinced that you can use a diesel engine with gas. No carburettor and how do you inject gas? I would think that a gas engine would have to bee on a spark ignition cycle.

 

Nick

[Supermalc]

There are petrol engined boats.

[TimYoung]

I'm not at all convinced that you can use a diesel engine with gas. No carburettor and how do you inject gas? I would think that a gas engine would have to bee on a spark ignition cycle.

 

Nick

 

 

Nick,

 

Diesels can run on LPG using a tiny bit of diesel to provide the ignition. Most of the explosion is provided by the gas.

 

Tim

[flatplane8]

I've run (and raced) my car in NZ solely on LPG for 10 years now, 5 litre V8 and no real problems. Runs very smoothly on LPG too. I have heard of people converting marine V8s to LPG - certainly all the commercial jet boats in NZ run on LPG. Its cheaper and you don't get surge problems when racing up rivers etc.

[Pirate]

Nick,

 

Diesels can run on LPG using a tiny bit of diesel to provide the ignition. Most of the explosion is provided by the gas.

 

Tim

 

Yep Tims right, havent you seen the Gas busses?

[Andy Bell]

I have been on three car fires in the last two years all of which were caused by cowboy/DIY conversions.

 

If your going to run on gas ensure that you have the conversion done by a professional and reputable engineer.

 

The consequences of not doing so could be deadly!!

 

 

Andy

[Chris M]

I'm fairly sure that the Boat Safety Scheme states that you can't use a duel fuel engine.

 

However you can use an engine designed to run solely on LPG.

[WJM]

Unlike diesel, LPG burns (explodes) so it is bad news on a boat. I think it can also build up in the bilges waiting for a spark. Bad news.

 

 

Aside; I see the new PLA Catamaran Patrol boats use two outboard engines - DIESEL outboards.

[ChrisPy]

you don't get surge problems when racing up rivers etc.

just what we need on the K&A then.

[Supermalc]

Unlike diesel, LPG burns (explodes) so it is bad news on a boat. I think it can also build up in the bilges waiting for a spark. Bad news.

 

Most boats already have LPG for cooking and heating. So carrying one less fuel, either petrol or diesel should make them safer, not more dangerous.

 

So as things stand, will it become a viable proposition to have a professional conversion done on boats when white diesel or petrol must be used for propulsion?

 

Are we going to see boats running on LPG become the norm; fitted from new, with no diesel or petrol tanks. Filling points would be at marinas, as well as white diesel, and petrol?

 

 

just what we need on the K&A then.

 

Yep....that should wake a few up.

 

Most likely stop them moaning at me, saying I'm going too fast at 3mph. People should look at the wash, or lack of before opening their gobs, or flapping their arms about.

 

Should also annoy the fishermen as well

Edited January 12, 2007 by Supermalc

[WJM]

The beauty of Diesel is it can never be dangerous - I really dont like having LPG on my boat, I keep it turned off all the time.

[Supermalc]

The beauty of Diesel is it can never be dangerous.

 

Sorry to be a bit dense, but would you mind explaining ........

[ChrisPy]

Sorry to be a bit dense, but would you mind explaining ........

to put it into perspective, on an oil refinery the process and storage areas are defined as hazardous. Only diesel powered engines are allowed, and exhausts have to be equipped with spark suppressors. The oil industry accepts that diesel is inherently safer than LPG or petrol in a location where there is a risk of fire or explosion. Goodenufforme.

Edited January 13, 2007 by chris polley

[Supermalc]

I was tactfully trying to extract a better explanation.

 

LPG and Petrol are more dangerous than diesel, because the fumes evaporate causing an explosive mixture with air. Diesel fumes do not.

 

However the statement that diesel can never be dangerous is incorrect, and to anyone reading this, could prove dangerous in itself.

 

Once burning, it burns hotter and longer, so diesel fires can actually be harder to put out.

 

Someone I used to know found out the hard way. As a youth he said diesel is safe, and dropped a match onto the diesel soaked shed floor. The shed was burnt down.

[WJM]

it is all relative - wood and soft furnishings can burn wildly, as can cooking oil, books, DVDs

 

What makes all these things different from LPG (and petrol) is that they do not evaporate to form an explosive gas. The hull of a boat is a perfect place to make an LPG fireball!

[Graham Davis]

Can't see anyone has said it yet, but

 

YOU CANNOT RUN A DIESEL ON LPG ALONE

 

This has been looked at in great detail in the 4x4 world, and the only system available injects a SMALL amount of LPG into the injectors. This does increase power but has very little effect on fuel consumption, it does however give a much cleaner burn, and therefore less emmisions.

 

I believe it was tried by one of the big bus companies for a while, but they gave it up because it hadn't saved them enough money.

[Djuwenda]

how about converting diesel engines to run on oil?

 

I am not very technically minded but thought they were easier done on plain diesel engines, like the ones often used to power narrowboats?

 

or am I talking rubbish?

[Supermalc]

But what about boats with engines DESIGNED to run on LPG. Fork trucks, busses to name but a couple have these engines fitted.

[gbmud]

Any petrol engine can be run on LPG. (OK, some smart Alec will point out the exeption!) You simply throw out the carb (or keep it so you can use petrol and add a mixer) and add an LPG mixer - which looks a little like a gas cooker burner turned inside out. You also need an evaporator - about the size of a kettle for a gas stove - connected to the engine's cooling system. The evaporator uses warm water from the engine to allow the liquid gas coming from a tank to evaporate without problems with the whole thing freezing up - remember when a liquid changes from a gas heat is lost - and then delivers it to the mixer.

 

I think that it is possible to convert a diesel engine to LPG, but it may be expensive - ultimately, all it can take is a FIP and injectors capable of delivering (and surviving) liquid propane rather than diesel. IIRC The Body Shop runs it's lorrys on CNG (Compressed Natural Gas) - not sure what engine conversion is needed for this.

 

LPG (when correctly installed) is regarded as safer than petrol in a motor car. The reasons are that; Rather than being kept in a folded and soldered thin steel sheet tank like petrol, it is in a strong, cylindrical pressure vessel and less likly to burst in the event of a crash; If there is a spillage or leak of LPG it evaporates straight away and blows away in the wind rather than hanging about in puddles or running about in rivulets. Sadly, this does not really apply on boats as crashes are usually slow speed afairs and it all goes on inside a steel (or GRP, wood etc) hull.

 

LPG is a sealed system. When filling your tank there is no vapour released as with petrol where the vapour in the tank is displaced by the liquid petrol going in. This has health, environmental and safety benfits.

 

Cars burn LPG at about the same rate as petrol. It is reckoned to contain about 10% less calories than petrol. LPG costs about 40-50p/l when road duty is applied to it. A car running LPG costs about the same to run as a similar diesel car, I am not sure how much less LPG might cost for non-road applications but if is similar then the savings may be negated by the increased consumption...

 

What about a bio-ethanol conversion for a boat? Not sure what would need to be changed (other than needing a petrol engine to start off with) to make a regular engine run on it. In the short term I think that we will see more and more cars using it on the road. It is made by fermenting sugar - I am sure we all know about that!

 

I have to say that I see bio-diesel (processed or not) as being a more likely fuel for use in boats, at least while the current diesel engine stock lasts - perhaps we will now see builders offering alternative fuel options as the cost of boating will increase as a result of the loss of red. I know that there are lots of for and against arguments (and we do not need to re-visit those) but you cannot argue that it is cheaper than white dino-diesel. And although price is the real issue for most here, it is carbon neutral too.

 

I am no expert on any of this, just a keen observer.

 

Cheers

 

Chris

[howardang]

Some people may remember that in the very late 1970's a hire company at Silsden - I think it was Pennine Line - built a fleet of boats which ran on gas. Their normal livery was light blue (Craven Maid, Craven Queen etc) but these boats were painted green to differentiate them from the rest of the fleet. They had a large gas tank at the stern which stored sufficient gas for at least 1 weeks cruising IIRC and the tank also supplied the cooker, boiler etc.

 

The propulsion was provided by a Renault car engine suitably converted to run on gas, and there were safety interlocks connected to gas detectors, purging fans etc which prevented the use of the gas if there was any leak.

 

I don't think they operated for more than a year or two.

 

Regards

 

Howard Anguish