Propane Engine

[NELOG]

Before I get to making my splitter, I didn't know if anyone had experience with gas engines that have been converted to propane. Specifically, are they more expensive fuelwise? Are they more or less reliable? Louder? HArder to work on/ have repaired? I'm thinking that an older forklift motor might work well.

 

[Old_School_Nut]

I have only been around 2 propane engines, and only used one on a regular basis. one on a forklift and the other on an aircraft tug. the engines are not loud at all, not any louder than gas. the engines also seam to burn cleaner and the oil seams to stay cleaner longer. the engines i have been around did not seam to have any more problems either, just routine maintenance. maintenance on the tug I used was easy as well, you could sit under the hood if you wanted, so you had all the room in the world, nothing different really under the hood other than the carb was replaced and I assume the ignition timing changed....

I cant say anything about what it costs to run one...

 

[redprospector]

When I was a kid we ran some pickups, and tractors on propane. The pickups seemed to loose a little power on propane, but you could switch back to gas when you were hauling a load. They lost a little mpg too but propane was real cheap so no one cared.

Andy

 

[kellog]

Propane

I have a propane fired emergency generator. I agree with Old School Nut in that it seems the oil stays cleaner (not sure why). The exhaust side also stays much cleaner. I don't know about the power issue but I am sure that would be easily found on the internet. My guess is that it takes more fuel to run it. Gasoline has a high specific power rating. I have nothing to compare the generator fuel consumption with so I cannot help you.

I think enviromentally it is much better. Small gas engines are terribly dirty but I believe propane is clean like natural gas.

It starts the engine extremely well. My generator is 12 years old and a three second crank (battery electric start) starts it every time without fail. I believe this is because it is in gaseous form when entering the engine.

I have never even so much as changed the spark plug in this engine (16 hp Briggs). Only oil changes. It runs automatically 15 minutes per week and of course kicks on when the power goes out which in our remote area is often.

I believe propane is a great fuel for a small engine but I think it is getting pricey these days. I would spend some time trying to figure the cost to run with propane.

 

[hbbyloggr]

We have a 6-cyl Chrysler 30KW generator fired with propane. The biggest problem we had was sizing the tank for the application and temperature. Get the BTU rating per hr and talk to your supplier about the temperatures you will be working in to determine tank size. This is by far the most important consideration, unless you are going to pre-heat the fuel.

I ran all tank sizes from 20#, 100#, 125 gal eventually finding the best size at 325 gal torpedo. It starts right up and does not freeze the tank up on long runs.

For a log splitter application you won't have a problem with the difference in power between fuels. Splitters don't put that much of a strain on engines.

Good luck,

Hbbyloggr

 

[jhellwig]

Real cold weather makes for hard starting.

 

[ShoerFast]

Real cold weather makes for hard starting.

Unless it is bellow -40 Deg. there is an adjustment or calibration problem if a propane engine is hard starting. If it will crank, it will start on propane.

There are a couple things you can do to keep the bottles from freezing, but if there just collecting a little ice at the liquid level, no big deal, unless your running for real long times. I ran an 83 gallon propane tank on vapor from Denver Colorado, to the Minnesota line. Setting the 83 gallon bottle up for a trip, I did not leak test it, and when I filled it, one of the black iron fittings had a flaw that leaked, (replacing the fitting would mean dumping 83 gallons of propane) so I swapped lines from liquid to vapor to semi freeze and run a lower bottle pressure. It had about a foot of ice around it, but never starved a small block Chevy at 65 mph. Sort of sucked, cause I was a little afraid to shut it down, of even stop at a light thinking the fumes would build.

Setting larger water-cooled engines up to run liquid to the vaporizer is the best way to go, a forklift engine would already be set up for that. If the engine has a vaporizer, and it still freezes the bottle, or even frost, turn the bottle so it's sipping liquid, not scavaging vapor.

Propane was way fun to run back in da day, when it was like .23 cents a gallon, but you take about an 80% power loss, and with gas at $2.50 a gallon, and the last time I bought propane at $2. bucks, it is a wash for effectiveness.

 

[infomet]

1g gasoline has 125KBTU
1g kero 135
1g propane 95
1KWH electric 3.4

So gasoline is 125/95=1.32 times as "valuable" as propane.
If propane is $2/g, then gasoline would be "worth" $2.64.

1g gas compares to 125/3.4=37KWH, which costs about $3 here, but electric motors are FAR more efficient than gas engines, so you shouold use electric if possible!

37KWH=37,000/750=50 HPhours at 100% efficiency from the motor.

A gallon of gas will do about 10HPh, far less than an electric motor at 90% (45HPh). In other words, you can't beat the power company!

Propane has no road tax, but is still pretty expensive. If gas is $2.50, propane has to be under 1.90 to break even. If you take off 40 cents road tax, it should be under $1.50!

Propane engines stay cleaner because gas has many components that do not burn well and contaminate the oil and go out as pollution.

Maybe I'll rig up my buzz saw for electric, at least when it's here in the yard!

 

[kellog]

Reply to Infomet

Infomet, nice analysis. This is really helpful for looking at the various power options.

You might want to chime in on an old thread that has had some new twists added. It’s the one called “renting or buying a splitter” but it has changed to a discussion of how to power a splitter. You may have some deep insight for the thread.

 

[Sodboa]

Convert a gas engine to propane pretty cool guide.

http://www.patooyee.com/propane/propane_1.htm

I wonder if you could find one of those meter-maid trucks cheap at a scrap yard.

 

[kellog]

Reply to Sodboa

Sodboa, I didn't realize there was so much going on in the propane power arena. This is great info. Seems like it only makes a lot of sense if you have a specific application that requires it. The conversion cost for small engines (12 hp and down) seems a bit steep unless you really have a pressing need for it or you could find some parts cheap. Thanks again.