Gas for an Out Board

Roy Smith · 26 May 2008, 18:48

I noticed an add to day about Gas conversations for cars
I wondered if with the cost of petrol going up and up
Is it possible to convert an out board to LPG (local garage as it at the pumps)
and would it be worth it, Costs etc.

Neil Harvey · 26 May 2008, 19:00

Is it possible, yes. For outboards? yes.

The question will be marine availability of LPG. there are only about 8 filling stations around the coast, and you need one of these because the marine valves are I think different to car valves, stopping you from filling up at land based petrol stations.

I guess you might be able to have the system fitted with car valves, but not sure about that. this would then stop you filling up at water side pumps but may not be an issue if you still have petrol tanks to fall back on.

Cost depends on the amount of tanks you have fitted and the capacity. Finding the space can be an issue as they have to be cylindrical somehow (I think you can also get doughnut shaped tanks to fit in spare wheel spaces in cars (but these are still kinda cylindrical if you get my point...). Guess you are loking at at least a couple of grand, but that was a few years ago based on inboard conversions and a fading memory.

Rogue Wave · 26 May 2008, 19:17

yuk

calarific content of LPG is something like 70% less than petrol so you gonna need a big tank of Fkkn explosive gas strapped to your bote or you convert your old tank space and get less range.

obviously four strokes can in theory be adapted but so far I haven't heard any sucess stories. If you want to go LPG wy not get a boat with an inboatd petrol fitted and convert that. (you wouldn't get an inboard petrol engine coded however.

Roy Smith · 26 May 2008, 21:39

I know nothing about LPG Etc, it just looked like a good idea

codprawn · 26 May 2008, 22:31

There is an easy source of LPG - it even comes with it's own tank. They tend to be big and orange/red. Usually have the word Calor on the side. They work great on the back of forklifts so why not?

i know Honda do kits for their Petrol gennies and I bet some of the smaller outboards are the same carbs...................

9D280 · 27 May 2008, 12:35

Surely the extra weight of lugging a tank of gas around is going to kill off any savings you will get by burning the gas in the first place?

And then add the cost of the conversion.......

codprawn · 27 May 2008, 12:54

Not really - a calor gas bottle empty is not really any heavier than an inboard tank. You would probably need 2x tanks feeding at the same time as outboards are a bit thirstier than a forklift.
You could have 2 bottles under the floor in cradles - the valve at the stern as you need liquid to flow not gas.

9D280 · 27 May 2008, 13:29

Aha! I knew there was a reason I used those lightweight plastic ones.......

bernithebiker · 27 May 2008, 17:34

I would think you'd be far better of going with ethanol, E85, assuming you can find it. It's just over half the price of petrol here.

All you need to do is apply a small ECU control box thingy to your engine to adjust timing and air/fuel ratios slightly, and Bob's your uncle, that's it.

Consumption will increase by about 10% but you're paying 50% less for the fuel. And it's bio!!!

I am currently using it in our Audi A2, completely standard, at a ratio of about 60% petrol to 40% E85.

(Don't forget normal petrol has up to 5% ethanol in it already).

Limey Linda · 27 May 2008, 17:41

Quote:

Originally Posted by codprawn

Not really - a calor gas bottle empty is not really any heavier than an inboard tank. You would probably need 2x tanks feeding at the same time as outboards are a bit thirstier than a forklift.
You could have 2 bottles under the floor in cradles - the valve at the stern as you need liquid to flow not gas.

I think you will find that instaling gas tanks under the deck without a drain hole for fumes at the lowest point is illegal and highly dangerous. Just how would you do that? It certainly is illegal in the US.

codprawn · 27 May 2008, 21:34

I think our laws only apply to inland waterways but I am prob wrong.

Why LPG should be any worse than petrol vapour is beyond me.

m chappelow · 28 May 2008, 11:52

the company i worked for in the 1980 s converted all the reps cars to lpg ,200 vehicles , all fords , the car still had to be started and run on petrol for about 5 mins to warm the engine then you could switch to gas there was not much difference at all power wise once the engine was warm or on a motorway . only advise was to switch to petrol every 30 miles or so for a few moments to lubricate the valve seatings. but have been told that with the newer unleaded engines the valves much harder and are much better suited for running with gas so no need to switch. only drawback found was the exhausts needed replacing a bit more due to having more water in them. our mechanic just drilled a very small hole in each silencer which cured the problem. the gas tank was like a donut shape which fitted in the spare wheel recess in the boot, down side was spare wheel was then always inthe way. the car went much further on gas than petrol mile for mile.

m chappelow · 28 May 2008, 12:02

the company i worked for in the 1980 s converted all the reps cars to lpg ,200 vehicles , all fords , the car still had to be started and run on petrol for about 5 mins to warm the engine then you could switch to gas there was not much difference at all power wise once the engine was warm or on a motorway . only advise was to switch to petrol every 30 miles or so for a few moments to lubricate the valve seatings. but have been told that with the newer unleaded engines the valves much harder and are much better suited for running with gas so no need to switch. only drawback found was the exhausts needed replacing a bit more due to having more water in them. our mechanic just drilled a very small hole in each silencer which cured the problem. the gas tank was like a donut shape which fitted in the spare wheel recess in the boot, down side was spare wheel was always inthe way.

JABS · 28 May 2008, 13:32

Quote:

Originally Posted by codprawn

I think our laws only apply to inland waterways but I am prob wrong.

Why LPG should be any worse than petrol vapour is beyond me.

It is because LPG is heavier than air and hangs around leading to problems if there is any static around.

In the US they have bilge blowers to clear petrol vapours before starting the engines.

In the UK, the gas stowage must be vented overboard from the lowest point, so it needs to be above the waterline.

I am not sure how far you would get on two portable cylinders. Consumption would be worse than petrol, since the cv is lower.

codprawn · 28 May 2008, 13:56

Quote:

Originally Posted by JABS

It is because LPG is heavier than air and hangs around leading to problems if there is any static around.

In the US they have bilge blowers to clear petrol vapours before starting the engines.

In the UK, the gas stowage must be vented overboard from the lowest point, so it needs to be above the waterline.

I am not sure how far you would get on two portable cylinders. Consumption would be worse than petrol, since the cv is lower.

Petrol vapours are heavier than air as well.

Petrol vapours are just as dangerous as LPG.

Why not use a bilge blower for LPG???

You could of course have 2 on deck tanks - much easier to change and safer but you lose space unless you use them as seats!!!

Searider · 28 May 2008, 19:28

About 10 years ago there was a big push to supply LPG on the water and quite a few boats were converted. Easy on a Twin V8 sunseeker as plenty of space below the cockpit.

Less easy on a RIB as a cylindrical tank will always take up relatively more space than a rectangular one.

There were also gas kits for various Honda outboards (not many other brands of four stroke 10 years ago!)

Hamble Harbour Masters launches had Hondas running on gas but went back to petrol - I think because of supply problems.

There was no gas available at Weymouth so those with Gas were restricted to the Solent which had several tanks or the Torquay area which also had a tank.

It was a chicken and egg situation. Noone wanted to pay to install a supply in their marina before there was sufficient demand. Owners didn't want to install a gas system in their boat until they could get gas at the places they wanted to visit.

I fear that the situation is the same now as it was then. Except the gas is more expensove now than it was.

stingraymax · 28 May 2008, 20:17

This company in the Netherlands converts out-inboards to LPG

http://www.midlandwatersports.nl/lpg

Roy Smith · 28 May 2008, 22:40

At what point will it be cost effective to convert to LPG with the way petrol prices are rising.
Is it better for the environment than petrol, why wont Marina owner put LPG tanks in.
With red diesel being phased out will petrol engines make a come back.
I have no answers, to any of the above, is there a niche market waiting to be taped.

codprawn · 28 May 2008, 22:50

The whole point of Calor bottles is you can get them anywhere!!! When they are empty just take them to a Petrol station and get more!!!

They work out at 50p per litre!!!

JABS · 29 May 2008, 10:02

Quote:

Originally Posted by codprawn

The whole point of Calor bottles is you can get them anywhere!!! When they are empty just take them to a Petrol station and get more!!!

They work out at 50p per litre!!!

I think you will find that Calor Gas costs around £2 per kg. That is just over a litre.

The only cost effective way to do this is with refillable bottles from such as Gaslow and buy the LPG from petrol stations.

Calor gas is probably the most expensive was to buy it. Camping gas is slightly more!