Compressed Natural Gas

[obezag]

On another thread "Uraijit" mentioned installing a natural gas kit on his engine. I've been wondering about this. We have a 1992 Wellcraft Eclipse with the 5.7L Mercruiser I/O. Feasibility? Coast Guard Approved? You can get a "fill station" installed at your home to hook into your gas supply in certain areas now. We have a gas well on our property so we get free gas. This would be very tempting. Comments?

 

[chiefalen]

Re: Compressed Natural Gas

i know down south they run trucks on farms goes back 30 years when i saw it and they run buses here in ny on natural gas.i too would like to know about this can it be done on the cheap and is it legal?

 

[tommays]

Re: Compressed Natural Gas

I would search web sights in europe as it done there becasue there fuel price have been high for a long time

 

[rthomas]

Re: Compressed Natural Gas

i would imagine the same stuff used to convert gas to propane would apply, that being said SIGN ME UP! IIRC it takes about twice the cng by volume to equal gasoline, but for the price i think i could find room for some extra tanks

 

[Hoss 350]

Re: Compressed Natural Gas

More that moderate interest. I run my farm truck on CNG (NOT Propane) and have been absolutely thrilled with the results.

FYI: Carberated Chevy 350 rated at 245 HP from factory.

The conversion kit (not counting tank cost) was just about $1000.

My next step is to alter the compression ratio (to 11.5 - 1) as CNG has an octane rating of about 130 and bring the HP and efficency up. (Targeting 300 HP) At the same time I will be completely eliminating the gasoline fuel system.

Once I have this done its time to look at doing it with the boat.

Want to hear your thoughts...

If someone was to offer a conversion system/service for your boat what would you consider to be a fair cost? (Keep in mind this includes fuel tanks, piping, air venting, engine set up, etc.) Most importantly keep in mind you will be paying around $.80 per gallon compared to gasoline. (Not really a gallon but has the same energy as a gallon of gasoline.)

If you made the conversion, would you consider buying a system to fill your tanks at home? (Assuming you have a natural gas supply.) Cost of the system is around $1,500 to fill a tank in 12 hours, or around $3,000 to fill the same tank in 5 hours.

Put big tanks on it. Gonna be hard to refuel when out and about. Other than that, have at it, my friend. Sounds like a heck of a good idea, if you can get it to work (and get it legal). "course, I've been boating for a bunch of years, don't believe I've ever been boarded and inspected by anyone, much less USCG. The furthest anything has ever gone is I had to show that I had a noise maker and show a life jacket for everyone on board.

 

[Bondo]

Re: Compressed Natural Gas

and the tanks (Carbon fiber for low weight) used have been tested extensively but the DOT in extreme crashes.

Ayuh,...

How Big are the tanks,... Portable,..??
How many gallons,..?? pounds,..??

 

[rodbolt]

Re: Compressed Natural Gas

aside from the fact that its not legal in the US, unlike an automobile, gas simply cant escape, it collects in boat bilges until the concentration reaches the correct air/fuel ratio. just after that bad things can happen.
while its a clean burning fuel and fairly efficient it has no place in a hull with any enclosures.
its tough enough with gasoline vapors, ever see a propane or CNG carb leak?
when the diaphram ruptures it can empty a 20 gallon tank rather rapidly.
the results of that in a boat would be a disaster for the operator,passengers and bystanders .

for the cost of the conversion you can simply fuel your boat for 3 seasons or so.
I actually use my boat more than average, I take it to worky worky and back 3 or 4 times a week, 11 miles each way.
I still only fill the tank 6 or so times a year, last fill up was 220 dollars.
next one3 will be about 250.
my suggestion would be to contact the USCG and ask if any systems are USCG and SAE rated for marine use and proceed accordingly.
the USCG regulations on marine use are not there simply to aggrevate, they are actually there to prevent folks from becoming a Darwin award winner.

 

[obezag]

Re: Compressed Natural Gas

That's my biggest concern. It would have to safe for marine application.

 

[rodbolt]

Re: Compressed Natural Gas

wasnt questioning your abilities, was stateing that as far as I am aware compressed LNG or CNG so far has not been approved for use in marine pleasure or commercial vessels in the US.
there is a reason for it.
its also why small boats use liquid alcohol for cooking and not bottled gas.
CNG and LNG in the natural state are gasses unlike gasoline, and we have enough explosions with gasoline.
kinda like the auto industry, certain modifications are simply not legal for use outside a sanctioned motorsports event and most of those have their own regulations.
I would start by contacting the USCG and finding out how or if you can legally make the conversion, or how to produce a kit for sale that will be USCG compliant
I know fuel prices are nasty, but there is a reason why the regulations are there.
and your not the only person in the past 75 years ever had that idea.
we used LPG and CNG forklifts and all the sperry fleet trucks at hunters point were duel fuel,CNG or gasoline.
and we had many many failures that allowed gas escape that in a confined space like an engine box, would have possibly been rather nasty.