Propane powered outboards

[Frantic]

Hey everyone, we just got one of these in here at my job and it looks pretty interesting! Heres the website: http://golehr.com/marine.php

I'm certainly in no financial position to pick one up, but these seem pretty interesting.

[joe16]

I'm considering one of these for my 16.  I'm tired of dealing with the old 2 stroke so I'm already looking for newer motors and the idea of not having to deal with the whole gas/ethanol situation is quite tempting.  As is the fact it runs on the standard camping propane canisters - apparently for an hour at full throttle.  I'd say most of the time I stay under 50% throttle on my current motor, and I'm typically only using the motor to leave the dock and come back, so I'd think a small canister would last me a while.  But replacement canisters would be easy to carry.  Weight is a bit lighter than comparable 4 stroke gas motors I've been looking at and price is fairly comparable.

Practical Sailor magazine had a test of the 5 HP version this month with positive results.  I'm looking at the 2.5 HP though, so I'm hoping that these motors perform consistently across all of their HP options (they have a 2.5 and 5 HP currently with 9.9 HP coming soon).

My only real concern is making sure that there are no leaks from any stored propane... since it is heavier than air, I wouldn't want it settling in the bottom of the cabin.  Seems like the spares would need to ride in the cockpit to be safe given the openness in the 16 from the lazarette compartment to the cabin.

Has anyone seen one of these in action or have one and can offer some feedback?

[Salty19]

No feedback on the motor...sounds very interesting.  Propane would be a great fuel for the occasional, low volume fuel use of small sailboats. Your concerns are valid about ethanol and the storage of propane.

One could store the bottles off a bracket or soft sided bag on the engine mount, or otherwise off the transom to keep any accidental fumes from filling the cabin.  Also you could get a high quality air and watertight storage box for the bottles, only open it while in the cockpit.

[wes]

Haven't sailed with one, but stopped by the Lehr demo at Annapolis last fall where they had one running in a bucket. It looked good. I see it as the alternative option that's most similar to gas in terms of power, motor weight, and noise. I was a little disappointed by the noise; had hoped it would be quieter but it was about the same as gas.

Personally I am holding out for an electric option with adequate power. The Torqeedo is on my short list but I have lingering concerns about whether it will get me home safely in a scary situation. Electric is improving all the time and it will be a happy day when I see the last of that gas tank.

Wes

[Shawn]

"My only real concern is making sure that there are no leaks from any stored propane... "

If you have a swim ladder mount a PVC pipe to the side of it with hose clamps. Put a reducer on the bottom of the pipe and a cover on top and it makes a very good propane locker. If a tank leaks it just flows overboard. Mine is sized for three tanks.

Shawn

[ribbed_rotting_rusting]

My boat is a 23' and the place that currently holds the gas/fuel at the rear of the cockpit would seem to be perfectly safe, it addresses the same concerns you would see with propane. If I not mistaken there has not be a larger propane tank developed for this particular outboard. this where my concern would be. I think a possible composite material has been mentioned. If I'm not mistaken automotive use of LP is usually based on an intake vacuum demand and the heating necessary to keep the regulator from freezing up when the pressure from the tank is dropped to normal operating pressure for gas(-maybe 15-45 PSI ?) is supplied by a hot water bypass from the cooling system. I guess my concern would be how the fuel line would be shut off from a larger tank if any off the supply lines are more than 2 feet long--I think an electrical solenoid is use on forklifts and automotive applications.  I guess I should say that I am talking to some guys about developing add on LP setups on portable generators--our part off the midwest has some pretty old electrical infrastructure and a lot of trees that come down from either wind or ice storms. I personally use a 3 point PTO unit on one of my tractors--diesel and able to move it.

[wes]

Lehr says their motor will run on either the small propane bottles attached directly to the motor, or the large 5 gal. "BBQ" type tank attached via hose. Doubt the 5 gal. tank would fit under the lid of the fuel compartment in my 19, unfortunately.

Wes

[joe16]

Shawn - you wouldn't happen to have a picture of that would you?

I would think that a fuel locker would typically be okay for storage but alas, my 16 has no such locker.  As I recall, the later 16's lost the lazarette storage in favor of a teak grate that would cover a fuel tank sitting on the cockpit floor.  I prefer the storage area myself, but it does mean that a fuel tank would take up foot space in the cockpit floor since the storage area is open to the cabin and not separated like fuel storage needs to be.

[skip1930]

Their is no reason why one can or can not run propane with it's 2,800 btu per cubic foot. Gas is about 180,000 per gallon.
You need a atmosphere compensating carburetor and a different sized jets.

Forklifts fitted with the same engine run propane, natural [1000 btu /cuft], gasoline, diesel, it's just a matter of having the right carburetor to create the vapor to bun.

Because the densities and vapor pressure vary for all fuels their will not be one ratio or carburetor or pulses from a fuel injector that will handle switching between fuels.

In the end, to make say 5 hp to push your boat at 4.5 knots, the same amount of btu's burned to make heat will be the same from any of these fuels discussed.
Only the amount in gallons or cubic foot of fuel used and pounds of air to burn will change. The heat stays the same.

We should buy 'heat' by the btu's, no matter what fuel we burn.

Some 3,412 btu/kw, some 12 thousand and some thing btu/hp...THE ONE problem with a natural or propane carburetor on forklifts is freezing the carburetor during the coefficient of expansion and then turning the vapor back into a liquid. Liquids don't burn, hence the engine runs like crud.

skip.

[Shawn]

Joe,

You can see the propane locker in this pic...



Shawn

[Salty19]

Shawn, nice looking boat and family.  Your PVC locker seems like the best solution unless you wanted to get fancy with wood/glass.

However I'm deducting points for the fenders in the water.  

I say go for the propane motor!  Will never have to deal with ethanol, spillage, hastle, etc.
They make perfect sense for small motors for sailboats.

Skip, I wish we could pay by the BTU.  Will never happen, costs of producing, refining, transporting and storage each fuel are different.  Throw in a supply a demand curve, it's easy to see propane costs more and probably always will, until we can pipe them right to gas stations, and of course drill baby drill.

Makes little difference here, might cost $6-$10 more per season at regular use (2X week, motoring 10 minutes total).  With no carb maintenance or fuel problems, it's actually a good investment.

I think you can get refillable 16oz containers that would fill with a standard 20 gal tank. Might be a lot more convenient and cheaper.

[Shawn]

Lol, I heard the same thing from my father who took the picture. That was first time out 'singlehanded' with my family and I was more worried about keeping the admiral calm/happy. 

I wouldn't refill the 1 pound bottles for outboard use. You can only get the bottles around 1/4 to 1/2 full with the adapter as there is not enough differential to fill them properly. Could be dangerous to run out at the wrong time.

Shawn

[joe16]

Shawn - thanks for the picture and the idea.  I may not have enough transom height on the 16 to get 3 bottles in there, but I'm going to look into that and see what I can fit.

Skip - you're not the only one thinking about things in BTU's... when my company puts together an energy model of a building the software calculates the total annual building energy use in kBTUs for both electricity and the various fuel usages.  That's probably primarily to get them in a common unit system and because the modeling software is really an advanced HVAC sizing program, but still an interesting tidbit I thought.

I was wondering about refilling the little canisters, but the pressure issue off a standard tank makes sense... Seems to me they pump the 20 lb containers full at the filling station, and I don't savor the idea of pumping propane at home (nor would the Admiral allow it, if I had to guess).

[Salty19]

Huh..didn't know that about the refillables!  Never mind then  

[Bob23]

Shawn:
   I'm ADDING POINTS  for the genuine Tilley hat!
bob23