propane?

Today I was browsing you tube and came across a propane outboard that was shown at a boat show in Miami. I thought I would post something and see if there are conversion kits or if anyone has any info about them. I wouldn't think it would be too difficult to do with a fourstroke but a 2 stroke im not sure about.

Re: propane?

Sweet.You could put in a plug in for the bbq.

Re: propane?

http://forums.iboats.com/showthread.php?t=533448&highlight=propane


they sell them here on iboats.

http://www.boatmotors.com/motorparts/index.cgi?pid=8098&flag=2


Don't know of any conversion kits.

You still have to lubricate the engine, so if you want to convert a 2 stroke, you will have to come up with an oiling system for all the bearings and rings.

A four stroke already has a lubrication system, so you are good to go.

Lehr still provides very limited info on these motors.

Local propane distributors has propane powered engines on all their transfer pumps.

According to them, there is no less maintenance on the engines.
In fact, they say they are quite finicky, but when running well, they work fine.

Re: propane?

I used to have a 1990 Chevy Silverado that was dual fuel propane/gasoline. One consideration with larger engines running propane is that you must evaporate the propane into a vapor form so it can burn. Liquid propane will not burn. I was able to evaporate mine by using an evaporator which pulled heat from the engine coolant before it was recycled and recooled into the radiator. For smaller outboards not requiring a high fuel input, this is not an issue. However on larger engines, the fuel must be evaporated to be used. Propane acts as a refrigeratant when pulled from a pressure vessel and will not deliver the full capacity that it can if allowed to evaporate in the tank due to cooling of the gas and eventually freezing up. This is solved by drawing liquid from the tank, running it through the evaporator and into a carb therefore maximizing BTU potential and minimizing vessel pressure drops. Conversion is possible however when you consider the weight of the tank, evaporation equipment, and the lower energy potential of LPG vs gasoline it makes sense to stay with gasoline for larger engines. Smaller outboards that draw less fuel can be reliably run from LPG without the freeze up issue.

I hope this all makes sense... I tried, lol!

Re: propane?

One benefit to propane vs gasoline is propane burns insanely cleaner than does gasoline. I changed the oil in that silverado after 4000 miles on propane alone and the oil looked just as good when it came out as the day it went in. Overall it is a superior fuel from a mechanical and environmental aspect, however it does have its weaknesses in the equipment required to make it work on large engines. 300,000 miles on a propane engine is equivalent to 100,000 on gasoline. I have personally seen many vehicles (service trucks) that have been on propane their entire life with 300,000 miles plus and never seen an engine rebuild. Overall the cleanliness of the fuel makes up for the lower energy potential in the long run in maintenance costs.

From a chemistry perspective, a gallon of gasoline weighs about 6 pounds while a gallon of propane weighs about 4 pounds. Gasoline is a heavier fuel therefore has more energy potential per unit volume. All that to say this, in order to receive the same amount of work, more LPG is required than an identical system running gasoline.

Re: propane?

Finding a way to run it on a 2 stroke would be ideal. The consumption of fuel is considerably less than gas from what I have heard. Plus the cost per gallon is cheaper. I just think it would be really neat to load up two or three propane tanks(the kind that forklifts use) and go out on the water for the weekend and not have to stop and pay $5 a gallon for fuel on the water. Plus it would be a big wow for other boaters to see how I get around. Also I have read that there is power loss with propane how much I don't know.

Re: propane?

I did a bit of research on propane, gasoline and natural gas. At the time gas was cheaper that it is today, but if you compared BTUs of gasoline to BTUs of propane, the cost was about the same. Natural gas is way cheaper, and has more BTUs that propane. That would be the stuff to use. The conversion technology should be about the same as for propane.