LPG as an a primary source of fuel

[Avocet]

We wanted to do some LPG conversions on various petrol vehicles at work but the vehicle manufacturer wouldn't give us a warranty on the engines unless the cylinder heads were swapped for their "LPG - spec" ones. I told them that I thought petrol engines that could run on unleaded already had hard valve seats and they told me that because LPG has a lesser cooling effect than petrol, the valve gear that was OK for unleaded petrol still wasn't up to continuous use with LPG.

 

[joeh]

i have eliminated even gas cooking on my boat by going electric ( inverter ). the peace of mind is priceless when i go out on my boat.

 

[richardandtracy]

Burning out valves

I know of 40 year old glider winches that have been running on LPG for all their lives. These engines run 8 hours a day, 3 days a week, with full power for 50 seconds after what can be a long idle period. The full power requirement can be as frequent as 30 times an hour (on a really cracking day) or down to 4 times an hour. In the evenings, for a hangar launch, I've seen the exhaust manifolds glow a dull red. I can't really imagine a worse operation profile.
However, the engines are incredibly reliable. These engines were built before 4 star went out of use, so have none of the 'hard valve seats' suggested for unleaded fuels.
I think fears about engine reliability are rather over stated. I doubt if the reliability of an lpg engine is going to be less than a petrol - which do tend to get more problems than diesel due to lower overall strength.

Regards,

Richard.

 

[neale]

Re: Burning out valves

I converted my boat and after 30 hours suffered head problems. Add this to the big problem of fuel availability and I wouldn't recommend.

Neale

 

[Slow_boat]

Re: Burning out valves

For safety reason I tend to agree that petrol on a boat isn't a brilliant idea. Even with red becoming taxed, how many yachts are really going to suffer? How much deisel does the average sailing yacht use per year, one tank full, maybe two or three?
The real losers will be motor boaters, but I have an answer to that.
Deisel engines were originaly designed to run on vegetable oil and older,non high performance deisels will still do so with no conversion, providing that a bit of deisel is run through for the anti knock chemicals every few tankfuls.
And before anyone says it can't be done, I know of a ford fiesta and a vauxhall fronterra that have been run like that for a couple of years with no problems so why not a boat?
I believe that there are some boats on the Broads doing just that for a government trial.