Converting outboards to autogas!!!

Stevie J · 30 March 2009, 11:34

A local garage converts petrol cars to autogas which comes in about £600+ for the convertion to 60p per litre fuel. The savings pay for the work pretty quickly! About 32 tanks of fuel!

I disussed the idea of converting my 90hp mariner outboard engine and he saw no reason why it couldn't be done. The 15L gas cannisters used for heaters etc could be used as convenient and safe fuel tanks (and are cheaper as they don't attract vehicle fuel duty! ssshhhhh!!). You'd still need a petrol supply for warming on start up and as as fall back should gas not be available, but changing gas tanks still way less messy than petrol!

My mariner is a bit long in the tooth and I was hoping to upgrade at some point to twin 60hp, this may double my costs sadly, but still at 2 miles to the litre it is worth considering over the life of a new engine.

Has anyone experience of outboard gas convertions?

Marinautic · 30 March 2009, 11:46

I believe some harbour master boats round here have run on lpg, either Hondas or Mariner's. 4 stroke of course.

Chris · 30 March 2009, 14:22

Quote:

Originally Posted by Stevie J

A local garage converts petrol cars to autogas which comes in about £600+ for the convertion to 60p per litre fuel. The savings pay for the work pretty quickly! About 32 tanks of fuel!

I disussed the idea of converting my 90hp mariner outboard engine and he saw no reason why it couldn't be done. The 15L gas cannisters used for heaters etc could be used as convenient and safe fuel tanks (and are cheaper as they don't attract vehicle fuel duty! ssshhhhh!!). You'd still need a petrol supply for warming on start up and as as fall back should gas not be available, but changing gas tanks still way less messy than petrol!

My mariner is a bit long in the tooth and I was hoping to upgrade at some point to twin 60hp, this may double my costs sadly, but still at 2 miles to the litre it is worth considering over the life of a new engine.

Has anyone experience of outboard gas convertions?

Im not a great fan of LPG conversions the engine tends to run hotter and on the Rangerover I had converted I had head gasket problems which I attribute to the gas conversion.

I would say any savings over the life of the engine would be offset by the shortening of its life !

codprawn · 30 March 2009, 15:17

But outboards have plenty of cooling anyway. It would be easy enough on a carb engine but what about some of the latest high tech ones? I know you can do it for cars but would anyone bother making the correct injection systems etc for an outboard as it's such a small market.

You could use the huge 47kg propane bottles on a big RIB or the smaller 19kg ones - you would have to put the valves facing the stern as it's liquid and not gas you want.

chewy · 30 March 2009, 15:20

£600 seems far too cheap for a LPG conversion.
What kits are they using?

Kernow Buoy · 30 March 2009, 15:30

If set up properly engines should have no problem on lpg, my V8 has been on it now for 8 years, we put in a high torque cam a couple of years ago and she was really clean inside. Lpg is a much higher octane than petrol BUT the ignition needs serious recalibration or problems will occur, I've got a power amp fitted that advances then retards for whichever fuel I'm on.

Rogue Wave · 30 March 2009, 16:30

Quote:

Originally Posted by Marinautic

I believe some harbour master boats round here have run on lpg, either Hondas or Mariner's. 4 stroke of course.

True but not for long, it was the hamble harbour master using Honda's

Poly · 31 March 2009, 00:22

Quote:

Originally Posted by chewy

£600 seems far too cheap for a LPG conversion.
What kits are they using?

- I know someone (local) who would probably pay this for a car conversion if that price is right...

chewy · 31 March 2009, 05:48

For my 5 cylinder Volvo its £1200 and thats very cheap.

codprawn · 02 April 2009, 00:01

Depends where you get the kits from - imported direct from Italy or Holland they are cheap but they are a lot cheaper here as well now.

http://www.lpg-kits.com/vsgi4.htm

Sequntial injection for a modern 4 cylinder is about £400.

You can install the kit yourself or get someone local to do it - then they will check it over and give you a proper certificate.

chewy · 02 April 2009, 05:51

I think its down to you get what you pay for though.

codprawn · 02 April 2009, 11:29

Quote:

Originally Posted by chewy

I think its down to you get what you pay for though.

Not always - some people choose to operate with much higher profit margins than others.............

Pete7 · 02 April 2009, 12:30

Quote:

Originally Posted by Stevie J

I disussed the idea of converting my 90hp mariner outboard engine and he saw no reason why it couldn't be done. Has anyone experience of outboard gas convertions?

Steve, you say the Mariner is a little long in the tooth, is the Mariner 2 or 4 stroke? because if its a 2 stroke how are you going to get the 2 stroke oil in it?

Pete

chewy · 02 April 2009, 13:24

Quote:

Originally Posted by codprawn

Not always - some people choose to operate with much higher profit margins than others.............

I know what your saying but I'd rather pay the extra for a decent kit with a guarantee so that the engine is covered.
You could fit a kit yourself get it passed and then have a component fail and your engines recked.
How does your insurance look upon having gas bottles piped to your engine....

codprawn · 02 April 2009, 16:18

It is decent kit and it does have a decent guarantee - in fact it's one of the best on the market.

chewy · 02 April 2009, 17:04

Does it have a guarantee if fitted DIY or does it have to be fitted by an approved installer?
Still haven't answered the question about gas bottles...

codprawn · 02 April 2009, 18:30

I am not sure but forklifts seem to manage.........

http://www.lpg-kits.com/

Look at their FAQ. I think it comes down to making sure the bottles fit properly in a suitable cradle.

willk · 02 April 2009, 18:51

Quote:

Originally Posted by chewy

Does it have a guarantee if fitted DIY or does it have to be fitted by an approved installer?
Still haven't answered the question about gas bottles...

Slightly off topic - I got a peek at a nice rib today, she had a GAS oven and hob fitted, and a fridge (possibly gas too). Cylinder storage must have been sorted somehow.

chewy · 02 April 2009, 19:25

Forklifts vent to atmosphere if a leak occurs rather than filling the bilge of your boat. I suppose you could have them mounted on the deck in a cradle?

I see the sight is quoting LPG as been cheaper than petrol on its home page. LPG actually gets you less mpg and will need serving every year too.
I think if it was worthwhile more people would do it.

codprawn · 03 April 2009, 00:18

Petrol is back up over 90p - LPG is 49p. You don't get the same mileage out of gas but it prob works out at 58p v 90p - when you are burning 40 or 50 litres an hour or even 90 at WOT that's quite a difference. Almost £30 an hour difference - not to be sneezed at - 20hrs WOT would pay for the kit!!!

And remember LPG for heating carries no road duty so even cheaper!!!