Running on LPG

[ben8473]

Right, anyone out there running a Super Air (with GT-40) on LPG?
If so, 1) who done the conversion and at what cost?

2) How much are you saving?

3) Any problems.

[rossl]

I Haven't got a super air, but to fill our boat with 80L of LPG costs us £30 and to fill other boats at the club with 80L petrol is £80, but the petrol boats do seem to get better fuel consuption, all in all I'd say LPG boats are 1/2 the price of petrol boats to run, and no fuel filters, fuel pumps, stale gas over winter to worry about.

It seems to be around £1000 - £1500 to convert to LPG depending on engine, if it's a super air I know TVSki in datchet do the conversion. But most dealers do it.

Cheers
ross

[saltwater_cowboy]

Running costs will depend on what your paying for fuel as it varies from 25p to about 40p per litre at clubs and 30p to 50p at forecourts.

You will be using about 10-20% more LPG than you would on petrol but a well designed system will minimise this loss or even eliminate it.

TV ski charge from £1500 to install LPG systems so you need to work out how long £1500 worth of fuel will last and how long you will keep the boat to see if you'll break even or profit from it.

There are other installers about but most charge around the same price.

Next you need to decide if you want LPG only or dual fuel.

LPG only will give you more power, better economy and will be cheaper but if you can't find gas anywhere your bolloxed. If going this route make sure you ask the dealer to return the old EFI petrol system and fuel tank as they may well forget to do so!

The two types of dual fuel systems out there are single point and multipoint.

Single point works in much the same way as a petrol carb. Its very simple, cheap and on the right engine a good system but its only reliable on an engine with equal volume intake manifolds (air filter in centre of the engine) and I think the GT40 EFI has an intake at one end of the manifold meaning the first cylinders get a rich mixture while the ones at the real get a weak mixture.

Now the best type is multipoint but there are very few installers offering this on the marine market. Multipoint uses injectors mounted next to the original petrol injectors and uses the vehicles original ECU (with an interface) to control the fuel. What you get is near factory fueling (often better power and economy if well dialed) but at a much higher cost. Multipoint also keeps your original petrol system incase you are feeling flush and want to pay 97p per litre!

On my boat I have a dual fuel system (single point as I have an equal volume intake) and keep my petrol tank full (added ballast) and use two gas tanks next to the engine (V drive) which again are great as added ballast. Working it out with about 1500lbs ballast in a 22ft v drive boat it costs about £5 per set and thats with paying 50p per litre for fuel.

LPG is extremly reliable, much more so than petrol so as long as the install is done correctly you'll be fine. The only area most users have trouble with is if the boat is raw water cooled you'll need to warm the boat up at 1200-1500 rpm for 5 mins or so during the winter months as with the water temp being low you can cause the vaporiser to freeze up.

I can't recommend anyone as I install all my own systems but if you want me to look any quotes over I can advise you if your being over charged.

[j3r3m7]

Ben,

We had our club Ski Brendella converted to LPG as we had access to an LPG tank at our lake.

Our costs for 1 season's club riding went from over 2000 quid down to 900. A good saving.

Benefits:
1) Easier filling of the gas tank, simply drive up to the gas jetty and fill her up. No more petrol can shuttle runs to the nearest garage
2) Ordering of gas was done by the 2000 l, so once or twice a season at most = less paperwork
3) Major cost benefit, approx 60% saving

Downsides...
1) People helping themselves to our gas thinking it was 'free'. This was stopped when we invested in a nice set of padlocks for the pump
2) As swc mentions, one problem we encountered was due to icing if we didn't warm the engine up correctly at the start of a session.
3) Slightly less power.. didn't really notice other than a reduced top speed

[saltwater_cowboy]

Rossl there is still a fuel filter. Its in the LPG shut off valve and should be replaced every year especially if using fuel from bottles as they can contain rust and other crud.

Not expensive and easy to do.

[rossl]

Is the filter on the shut off valve in the multivalve on the tank? or is there an other one?

cheers
rossl