Propane Powered - - The Friendliest Tractor Forum and Best Place for Tractor Information
Backyard Round Table - L & G Tractor Related Topics Lawn and Garden Tractor Related Topics General Discussion Board

Thread Tools Display Modes
post #1 of 10 Old 04-05-2012, 08:42 PM Thread Starter
Senior MTF Member
Join Date: Feb 2010
Location: mississippi
Posts: 538
Propane Powered

At work today they had two BOB CAT 60'' zero turns delivered set up on propane.They have a GENERAC two cylinder air cooled engine in them. Don't know how they're gonna work out because where i used to work we had our trucks on it and you had to have the regulator hooked to the coolant system to keep it from freezing up.

2007 John Deere 5203 2009 John Deere X500 48'' deck 2010 John Deere X300 42'' deck And too many attachments to list
scm is offline  
Sponsored Links
post #2 of 10 Old 04-06-2012, 12:29 AM
Slowly turning green...
lobsterbox's Avatar
Join Date: Sep 2009
Location: Alberta, Canada
Posts: 1,244
Images: 3
Re: Propane Powered

Wow, that's a pretty neat idea running mowers on propane. It must save them a ton of money on fuel! My grandfather has a 2 cylinder air cooled Gentrac engine set up to run nat. gas as part of an auxiliary power unit. As far as I know, those engines are based on the popular Chinese built honda clones that we all here so much about. I am curious to see how alternative fuel engines like these preform in such diverse applications. I believe that propane only liquifies in extreme cold (-40 C or so) so that shouldn't be an issue (I assume) given these are to run in the summer.

My Youtube Channel: lobsterbox20
2000 John Deere 425 w/ 54" Deck, 54" Blade, 50" Tiller, 47" & 46" Snowblowers, Cosy Cab ~400hrs
1992 John Deere 322 w/ 50" & 48" Deck, 46" Snowblower, 42" Tiller, ~1300hrs
1981 Case 646 Loader w/ 44" Deck, 42" Tiller, 3 Point Hitch
1978 Sears SS/19.9 Twin w/ 42" Deck ~350hrs (trailer queen).
1975 Roper RT/16 w/ Tote Box, Sickle Mower & 3PH.
lobsterbox is offline  
post #3 of 10 Old 04-06-2012, 04:32 AM
15,000+ Posts & Climbing
Join Date: Jun 2009
Location: Sault Ste Marie, Ontario
Posts: 17,909
Re: Propane Powered

I believe that most, if not all, propane engines run on liquid propane, not propane vapour like a barbecue. When the liquid propane vapourizes at the carb, it extracts heat from the area for vapourization and that can lead to ice buildup on a humid day at the right temperature and load conditions.

Even a gasoline carb will ice up under the right, above freezing, conditions. That's why there is an exhaust crossover on V type engines and the intake manifold is often nested with the exhaust manifold of inline engines.

It's not fun trying to slow down from interstate speeds for a rest area with the carb and its linkages covered with an inch thick layer of ice because that crossover is plugged.

Propane liquifies at -40, C or F - same temp, at atmospheric pressure. At +68*F (20*C), it takes about 250 psi to make it liquify. You won't start a propane powered vehicle at -40* without a tank heater, and it is possible to have carb icing on a relatively cool foggy morning unless there is heat applied to the carb somehow. ( For propane, it isn't called a carb, but I forget offhand the proper term. Oldtimers disease.)


Click for The Hydraulics Forum!

Sometimes you get on a roll, sometimes the roll gets on you.

In Service
MF GC2310, Husqvarna YTH20B42T

Down for Repairs
MF1655 w/ FEL, MF1655, MF12H, MF8H, MF7H
Spending too much time on MTF to work on my toys.
TUDOR is online now  
Sponsored Links
post #4 of 10 Old 04-06-2012, 08:51 AM
Loving Life :-)
marlboro180's Avatar
Join Date: Jan 2010
Location: WI, eh
Posts: 4,007
Re: Propane Powered

Ferris also has a propane mower, big commercial ZTR. Twins tanks on it , and they are rather large. Gravely, Dixie Chopper have propane models as well as others.

Case 222, 448 ,648 LBH ,, Craftsman 11-36, DLT 3000, Ransomes Motor 180 x 2 :-) Gilson RE-11, Plymouth Gilson something,?and some Hondas and other stuff- the e c l e c ti c gang LOL "Got Solar?"
Help save the DLandreth Seed Company
marlboro180 is offline  
post #5 of 10 Old 04-06-2012, 12:20 PM
Senior MTF Member
john9001's Avatar
Join Date: Jun 2010
Location: south west pa
Posts: 905
Images: 1
Re: Propane Powered

How Does a Propane Engine Work?

A propane engine works similar to a regular gas motor. The propane is pulled from the tank and is switched to a vapor to allow it run into the fuel lines. The vapor is passed through a mixer that combines the vapor with air. The mixture is then sent through the combustion process by a fuel injector system. The injection system is a sequential process that sprays into each chamber one at a time. The motor is very similar to a gasoline motor as it is a timed process. Each cylinder has to be firing in sequential order for it to function correctly.

How Much Maintenance Is Required?

Since the propane is a gas and not a liquid, it's said to burn cleaner while in the combustion chamber. There is virtually no residue, and the time between oil changes is much greater. The propane does burn hotter than gasoline, so the oil will be become more viscous over the course of time. Intervals on the oil change is every 10,000 miles as opposed to every 3,000 to 5,000 miles.

Read more: How Does a Propane Engine Work? |
john9001 is offline  
post #6 of 10 Old 04-06-2012, 12:38 PM
Retired Mod
dirtybernie's Avatar
Join Date: May 2005
Location: c-ville KY
Posts: 3,734
Images: 1
Re: Propane Powered

I had a briggs 8hp generator that had been converted to propane. I dont know how many hours it had on it, but it was a 1973 & when I pulled the head it was like looking at a brand new engine! no carbon whatsoever & a very healthy crosshatch in the cyl. that stuff burns clean.
dirtybernie is offline  
post #7 of 10 Old 04-06-2012, 02:25 PM
5000 Strong & Climbing
Join Date: Aug 2009
Location: Washington
Posts: 5,115
Re: Propane Powered

Since propane has fewer BTUs per gallon than gasoline a given engine will produce less horsepower on propane than it will on gasoline. If an engine is properly set up for propane this lower BTU/gallon disadvantage can be largely offset due to the higher octane rating of the propane. At 110 octane propane allows running a higher compression ratio and advanced ignition timing. Since the higher compression generally requires a wider plug gap and stronger spark an improved ignition system is often required. The engine must be designed to handle the higher pressures of the increased compression ratio or early mechanical failure may be expected. Lack of any lubricating additives or valve seat protection dictates that hard valve seats and Stellite exhaust valves be used.

Depending on the type of fuel system the engine has, carbureted or injected, the fuel may enter the air stream as a liquid or vapor. If the liquid is injected just ahead of the intake valve it vaporizes and cools, there by condensing, the air stream entering the cylinder. This vaporization is completed after the intake valve closes which allows more oxygen to have entered the cylinder and boosts the compression pressure. The resulting HP increase is significant over the vapor fed engine.

When vapor is fed thru the intake manifold the two methods usually employed include vapor from the tank and liquid fed to a vaporizer and then regulated into the intake air stream. Using this method the vapor displaces considerable intake air and results in less oxygen being taken into the cylinder. While less expensive to produce, and somewhat easier to maintain, this method is inferior to the injection method for engine efficiency and HP output but much more common to find in use.

Vaporizers commonly used are liquid heated, from the engine cooling system, and air heated. I've seen vaporizers that used the heated air from the cooling system on air cooled engines but have also seen a couple that had a heat collection system from the exhaust manifold. Both methods were thermostatically controlled and seemed to work well.

The tank vapor systems I've seen were used on stationary engines and fed from large tanks with sufficient surface area to allow heat absorption sufficient to supply the engines needs.

Personally I like using propane as a fuel source when the engine has been properly set up for this purpose. Seldom have I seen engines that were thus set up being used on small equipment. The efficiency, and cost effectiveness, of propane on a "conversion" that has had only the fuel system changed is highly questionable.

Just my opinion on all this of course, your milage may vary.


A gun and a parachute are much the same. When you need one nothing else will really suffice.
Tencubed is offline  
post #8 of 10 Old 04-06-2012, 03:48 PM
Senior MTF Member
Join Date: Sep 2009
Location: Austria
Posts: 843
Re: Propane Powered

I have seen a few european manufacturers use lpg for their products.

7sleeper is offline  
post #9 of 10 Old 04-06-2012, 07:09 PM
'Simple' MTF Member
Talntedmrgreen's Avatar
Join Date: Feb 2011
Location: Dorr, Michigan
Posts: 4,181
Images: 59
Re: Propane Powered

Allis offered an LP conversion kit for their B-10 model in the 1964 catalog. I've seen a picture of only one, last year someplace at a summer show, but cannot track that down. The kit appeared to include everything on the intake side, and mounting hardware for holding a tank over the front of the hood.

Reading TenCubed's post, I wonder what else was needed? Curious if they cranked up the compression with a replacement head, or accepted the HP loss...
Talntedmrgreen is offline  
post #10 of 10 Old 04-06-2012, 09:12 PM
5000 Strong & Climbing
Join Date: Apr 2009
Location: Pennsylvania
Posts: 5,747
Re: Propane Powered

Personally, I don't see the advantage of propane for any equipment used outside. It can be hard starting, dangerous to transport, can have bridge and tunnel restrictions, and the vapor is heavier than air if it leaks. Granted, it may be easier on the engine in terms of wear- but most OPE engines will die from dust or overheating before the fuel kills them. The fuel would have to be almost free for me to consider it- same as the new NG pickups that will be available to fleets next year- with their $10,000 option.

Diesel engines on OPE are a much better option IMO- and in pickups, too.
rscurtis is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the - The Friendliest Tractor Forum and Best Place for Tractor Information forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome