Propane Fueled Outboards

What do you think guys? Is there a market for small outboards fueled by propane? Let me hear your thoughts on the idea.

HopCar wrote:
What do you think guys? Is there a market for small outboards fueled by propane? Let me hear your thoughts on the idea.

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*Not really...but most 4 stroke (not sure about 2 stroke with oil injection)carbed engines are easily modified to run on propane.

It would either be another fuel to lug around for many or it would be a PIA to get some more fuel quickly unless you always carried around enough propane to have for the dingy.

HopCar wrote:
What do you think guys? Is there a market for small outboards fueled by propane? Let me hear your thoughts on the idea.

Free enterprise being what it is, I think that if there were a market for propane fueled outboards, someone would already be making them.

I wouldn't expect to go very far on the small disposable canisters and lugging a 20lb propane tank around on a dinghy doesn't seem very practical either.* Propane is every bit as dangerous as gasoline if not handled and stored properly.

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I don't have a propane stove on my boat so I haven't paid attention, do many marinas sell propane? I agree with the draw backs both of you mentioned. To me there are a few advantages. Propane is a lot cleaner to handle than gasoline and produces cleaner exhaust. In my case the small outboard may sit unused for months at a time and I wouldn't have to worry about the carb getting gummed up. I converted my gasoline emergency generator to propane for that reason. It can sit a year or more and fires right up.

HopCar wrote:
I don't have a propane stove on my boat so I haven't paid attention, do many marinas sell propane?

No, marinas do not normally sell propane.* Many home centers and even grocery stores now have cylinder exchange programs for the common 20 lb tanks folks use for home grills though.

You DO NOT want to store propane in enclosed areas on boats.* It's just like gasoline in that respect.

Unlike a gasoline powered outboard, you can't "top off the tank" with propane.* You use what's in the tank and then replace it or take it to be refilled.* I have a propane stove on my boat and a spare tank.* When the active tank is empty, it's a small inconvenience to replace it with the spare.* You wouldn't want to carry a spare 20 lb propane tank on your dinghy.

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The big heavy steel 20 pound propane tanks would be a big pain, but what about a light weight fiberglass tank designed for marine use?

HopCar wrote:*

*In my case the small outboard may sit unused for months at a time and I wouldn't have to worry about the carb getting gummed up. I converted my gasoline emergency generator to propane for that reason. It can sit a year or more and fires right up.

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The best reason for the conversion by far.* *

If it became popular, or maybe what is need for it to become popular is a tank that would fit in the bottom of the dink that is flat and long.*Or one that would hang on the transom inside the boat like a few of the plastic*gas tanks do.* *Structurally it would be strong enough to stand on so on the bottom of the floor or under a seat would work.

An AL or the new fiberglass tanks in the right shape might be the answer.* It weighs less than gas by about 2 lbs a gallon and cost half as much at $2.19 a gal.

JD, the cost is an interesting point, but probably not very significant given how little gasoline you use for a dinghy motor. You also get fewer BTU's per gallon of propane so the cost saving isn't quite as good as it first looks. I like your tank idea.

I wonder how long you could run say a 2 hp dinghy motor on a pound of propane? Any body know how to calculate that?

Compared to gasoline the energy content of LPG is 74%

HopCar wrote:
I wonder how long you could run say a 2 hp dinghy motor on a pound of propane? Any body know how to calculate that?

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Here's my take on it...

This web forum post, on a forum coincidentally also owned and operated by our new Master and Commander Andy R,* discusses a comparison of the Honda eu2000I propane conversion.* He states he gets 4 gas tanks worth of running time out of a 20 lb propane tank.* The eu2000i gas tank is 1.1 US gal.* The 1.1 US gal gas tank lasts 4 hrs under high load.*

My Honda 2hp motor runs 50 mins at WOT on*0.26 US gal.* (That's over 16 nmpg at 5 kts!!)**If *20 Lbs of propane is equivalent to 4.4 US gal gas, then one lb propane = 0.22 gal gas, or approximately 85% (0.22/0.26=0.85)*of a Honda BF2D 2hp gas tank.** So rather than a 50 minute run on a full gas tank, the BF2D would run about 42 minutes on a one lb propane bottle.*

Note: Propane contains*fewer*BTUs*than an equivalent volume of*gas, but this difference is already accomodated in the 'running time' comparison above.*

OK guys, take a look at my numbers and fire away.* Am I close?

I am still hoping we will get off foreign oil and start converting to natural gas/propane as we have a lot of it.* About 15+ years ago we had a plant pick up converted to propane as all our plant fork lifts are propane.** It would not take much to convert/change over.

All of the riverboats on the San Antonio Riverwalk run off propane. Don't know if they converted gas ones or bought them that way though.

Flyright, I kind of like your numbers. My wild ass guess was about half an hour run time on a pound of propane.

I think we could write up a grant proposal, sell it as a green project and get millions in startup money from both wall st. and the guvmint to develop a propane outboard motor carburetor. Then, after a year with a large salary, golden parachute, & global hobnobbing, I'll declare bankruptcy, default on my loans and grants, and retire to Curacao.

Ken

Don't most of us have propane stoves and diesel engines?* If your outboards ran on propane,*you wouldn't need to carry a third fuel (gasoline).* Smallish propane cylinders sound a lot more*handy than*spillable gasoline containers.

Ken, you'll get a much bigger grant if you can work "Solar" into the grant proposal. The current administration is a sucker for anything with the word solar in it.

markpierce wrote:
Don't most of us have propane stoves and diesel engines?* If your outboards ran on propane,*you wouldn't need to carry a third fuel (gasoline).* Smallish propane cylinders sound a lot more*handy than*spillable gasoline containers.

I don't believe we (as consumers) can legally refill the small cylinders so we would still have to carry two different sizes. And we would have to carry at least one spare on the dinghy.* It's hard to tell how much propane is left in the tank but with gasoline you can just unscrew the top and look.

I can top off my dinghy motor from a one gallon gas jug, put the jug in the dinghy with me, and go for many hours.* If, by some chance I ran out of gasoline, I could even call TowBoatUS and have them bring me more (that's part of the membership deal).* I could buy gasoline at most marinas if I was getting low.

Powered by propane, once I run out, I'm out of luck.* Row or get towed back to the mother ship.

I don't think propane (or electric for that matter) are quite ready for prime time for boat propulsion.

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-- Edited by rwidman on Thursday 26th of January 2012 06:41:28 AM

pound of propane? Propane has about 95,000BTU per gal. Gas about 120,000BTU

The biggest advantage to propane is its store ability.

Todays ethanol gas absorbs water , and in a month its garbage.

Gas is even worse with oil mixed in .

Propane could be ancient and will work 100%.

Additionally gas evaporates out of the carb and leaves varnish, the propane does not seem to.

For these reasons , as well as the non poisonous exhaust many RV's prefer propane noisemakers.

rwidman wrote:* It's hard to tell how much propane is left in the tank but with gasoline you can just unscrew the top and look.*

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*Not so with the new fiberglass tanks.* They are transparent like a plastic water or holding tank is.**I think*they only come in one configuration @*5, 10 and 20 lbs**at present but if the demand for a*different size or shape would arise then I'm sure they would become available.

Just do a Google* "fiberglass propane tanks" search.

I like the idea.* Two tanks one on the boat and one in the dink. When one get's toward empty you just switch out before heading out on your adventure.* May be carry a few one pounders to get you buy if you need to.

JD wrote:rwidman wrote:* It's hard to tell how much propane is left in the tank but with gasoline you can just unscrew the top and look.*

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*Not so with the new fiberglass tanks.* They are transparent like a plastic water or holding tank is.**I think*they only come in one configuration @*5, 10 and 20 lbs**at present but if the demand for a*different size or shape would arise then I'm sure they would become available..

Still, you can't refill them and with a fiberglass tank, you can't just exchange it for a full one at the grocery store, gas station, or home center.* You would have to go to a place that refills them on site.

It's possible, I just don't see the point.

BTW: I weigh my metal tanks with a fish scale to see how much propane is left.

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-- Edited by rwidman on Thursday 26th of January 2012 09:32:10 AM

I think there might be a reason you don't see different shape propane containers. It's probably not practical to change the shape of the container. It may be possible to put multiple smaller containers into a larger package shape which would then appear to conform to someones idea of the perfect shape. I'll include that research in my grant proposal. It should gather another couple of million siphonable dollars.

And great idea, I forget who proposed it, (thank you, a Vice Chairmans job with golden parachute awaits you) but I'll add a solar charging panel to the reconfigured propane package. It will charge the lithium-unobtainium battery for the safety warning system which warns if the CO emmisions exceed some radically miniscule number.

Who said get rich quick schemes didn't work? Now if I could just find someone with a little start-up money..........

About 3 years ago ordered a fiberglass cylinder, when I went to have it filled I was informed that they are not legal to fill in Louisiana, and I was told that is so in several other states also. So if you are in the US best to check in your area, or wherever you may need to have one filled while travelling, beforehand. I had bought it from the local West Marine store, the first (and only) one they sold. They took it back and I bought an Aluminum one which is no problem to have filled here.
The state inspector told me there have been cases of the fiberglass (composite) tank top and bottom halves separating and exploding, I think that may be BS, but they were sticking to it. Being able to see the fuel level in the fiberglass tanks is a very nice feature.
I'm guessing one of our politicos has a steel tank factory somewhere.
Maybe That reg has changed I'll check.

Here is a link to an article by Parlatore re propane outboards
http://oceanlines.biz/2009/12/propane-for-the-dinghy-outboard-part-2/
Steve W

2bucks wrote:
...*Now if I could just find someone with a little start-up money..........

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*I hear Doug and Baker have deeper pockets than they had a few weeks ago.** :idea:

Steve wrote:The state inspector told me there have been cases of the fiberglass (composite) tank top and bottom halves separating and exploding, I think that may be BS, but they were sticking to it.

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*Sounds like not enough Gumbo was offered to the correct person.

I don't think the little one pound bottles would be the primary way to fuel a propane outboard. I think you would replace your plastic jerry cans of gas with fiberglass propane tanks and just swap them out as they empty. No messy trying to pour gasoline from can to tank. Finding a place to refill the tanks when in port will be a little harder than finding a gas station but propane is sold world wide and a lot of people cruise the world with propane stoves. I would probably carry a one pound canister in the dinghy as a back up fuel supply. The one pound canisters can be refilled but they really aren't designed for it. The problem is that you need to vent gas from them as liquid propane goes in or you won't get a good fill. To vent them you need to pull on the stem in the little safety valve while the liquid is going in. The valve was not designed for this and it's not easy to do. If somebody thought there was a market for it and could get liability insurance, they could design a system for refilling small tanks at home.
Another possible problem with propane as a fuel is that it seems harder to start an engine on propane than gasoline. This statement comes from my own experience with just one engine so it may be wrong. I have a small generator that will run on gasoline or propane. I can hand start it on gasoline pretty easy but I have to use the electric start for propane. I have hand started it on propane but it's a lot of work. There's a thought, what if the engine could be run on either propane or gasoline? Any advantage to that?

HopCar wrote:
The problem is that you need to vent gas from them as liquid propane goes in or you won't get a good fill. To vent them you need to pull on the stem in the little safety valve while the liquid is going in. The valve was not designed for this and it's not easy to do. If somebody thought there was a market for it and could get liability insurance, they could design a system for refilling small tanks at home.


There's a thought, what if the engine could be run on either propane or gasoline? Any advantage to that?

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http://www.harborfreight.com/propane-bottle-refill-kit-45989.html

Harbor Freight has these propane refill adapters for around $20.* I keep one on the boat in case I need to refill a small bottle for my grill.* To refill, you place the small bottle in the fridge for an hour to drop its temperature.* Then connect the adapter to the 2 tanks, turn the large tank upside down, open the large tank valve.* In about a minute, the flow will stop (the pressures equalize), close the valve, turn tank upright and disconnect the adapter.*



http://www.propane-generators.com/type_2.html

Here's a company that sells bi-fuel (Gasoline & High Pressure Propane) conversion kits for small generators.**The model linked above*is designed for engines 13HP and higher.* The model for smaller engines does not accomodate engine idling and throttle use.* The adapter fits inline between the air cleaner and the carb.* They are common among the RV community on the popular Honda eu2000i.* It might be a good starting point to experiment with adapting for marine outboard use.*

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-- Edited by FlyWright on Thursday 26th of January 2012 11:00:56 AM

Harbor Freight has these propane refill adapters for around $20.* I keep one on the boat in case I need to refill a small bottle for my grill.* To refill, you place the small bottle in the fridge for an hour to drop its temperature.* Then connect the adapter to the 2 tanks, turn the large tank upside down, open the large tank valve.* In about a minute, the flow will stop (the pressures equalize), close the valve, turn tank upright and disconnect the adapter.*

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I have used one of these adapters for 20 years. It works very well.I normally freeze the small tanks for an hour then fill. After filling I set the bottles outside in the sun for about an hour and let them vent if they need to (they usually do).

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Another consideration might be keeping the vaporizer/ regulator from freezing up. We have done tons of gasoline to LP conversions on forklift engines over the years and on a 50 HP engine you have to tap into the cooling system and flow coolant through the vap/Reg or it will freeze solid and stop working. I also remember seeing a small LP powered carry deck crane once that only used a short length of looped tubing with coolant inside to avoid freezing. I also repaired a hand operated floor scrubber used in a supermarket. It was an LP powered Honda engine, but the vap/ Reg had no coolant at all and it did fine. I assume the amount of fuel being vaporized was so small it was a non issue.

FF wrote:
For these reasons , as well as the non poisonous exhaust many RV's prefer propane noisemakers.

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*I read that line from FF and it's been sitting in the back of my mind for a few days now. Because I spend 7 months a year in my RV,*I am part of a number of RV forums and almost never hear people talk about their propane generators. Not about how good they are, not about how bad they are, just don't talk about them.

So, I happened across a current thread on one RV forum asking about replacing a stolen genset with propane powered. 8 out of 8 responders said don't get propane power for a replacement generator. http://www.irv2.com/forums/f84/propane-or-gas-113849.html

I personally have a diesel powered rv and wouldn't even consider going with anything but diesel genset, just like my boat, diesel main, diesel gen.

It's entirely possible that there are a bunch of propane generator owners that never have problems and never feel like posting about how well they work. I just don't know where they are.

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Ken

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