Propane Conversion

[turbofiat124]

I have always wanted to do a propane conversion on my gas lawn mower engine. I've seen different ways of doing it. I've seen people that just put a hose from the propane tank right into the intake. I have also seen people take off the gas line and just run propane into the carburetor. This is thr method I would like to do. If anyone has already done this and has tips or plans on how to convert to propane I would really appreciate that.

I seen where some guy removed the carburator all together and regulated the engine speed using the needle valve from a propane torch.

Simple Conversion To Run A Lawnmower On Propane.

I guess like how engine speed is regulated on a diesel engine where the throttle controls how much fuel is sent into the engine where as on a gasoline engine the throttle plate to control engine speed.

This might work OK providing the engine runs at a constant speed govenor never kicks. I still don't see how this setup would be efficient.

Maybe on a generator , like as I said where the engine runs at a constant speed and there is no need for the fuel mixture to be constantly adjusted.

 

[panabiker]

So, does anybody know if propane gives an cost advantage over gasoline at current prices of gas and retail propane refill?

 

[Carscw]

So, does anybody know if propane gives an cost advantage over gasoline at current prices of gas and retail propane refill?

With gas being $3.05 a gallon right now I don't see that you would really save enough money to make it worth it

 

[Terry CleanFuel]

I have alot of experience w/propane powered equipment, and i can tell you what you have mentioned as methods for feeding the fuel are both VERY dangerous. While you didn't mention the type of LP tank, I have to assume you would use a standard home grill tank. First, the pressure of the LP must be reduced from tank pressure (300+psi) to under 5psi. Second, LP is heavier than air and must be mixed w/ intake air as it is introduced into the venturi. After that it could work very well.

Whoa Nellie! Propane tank pressure is typically 70-200psi depending upon ambient temperature. Yes, it does need to be regulated but you need a "demand" regulator to do it.

If you want the low-down go here. There's step by step instructions:

Clean Fuel LPG Propane Conversions, Eco-friendly

 

[Terry CleanFuel]

So, does anybody know if propane gives an cost advantage over gasoline at current prices of gas and retail propane refill?

Here in Boise Propane has a price advantage of 60%. Not only that but propane is 80% less polluting and you can extend oilchanges by three.

 

[Terry CleanFuel]

I've converted several Kohler engines from gasoline to LP. Mostly M8 and M18-20 engines. We replaced the gasoline carb with a gaseous carb and ran a two stage regulator between the tank and carb. The two stage regulator allows you to run tank pressure into one side and then directly into the carb from the other side. The two stage regulator has a primer button for cold starting. We got the regulators and the carbs from Allgas Industries. I have also done some older K series like the Kohler K582 using primary and secondary regulators on them. On those we ran a solenoid valve in the fuel line using voltage from the coil feed to open and close the valve. Usually had to run about an .018 plug gap. Some regultors may require a balance line on the secondary side. The ones I did we ran a line from a balance block between the carb and intake port on the block to the secondary regulator. You need to pay very close attention to the fuel/air mixture with gaseous fuel. If you run too rich a mixture, you could fry the piston. So the mixture and air filter/cleaner has to be kept in top shape at all times. Gaseous fuel does not have the same BTU's that gasoline does, so there will be a slight drop in power with LP. And like was stated earlier, running gaseous fuel into a gasoline carb could be very dangerous!!!

Kohler twins are not the greatest engine to convert to propane because of their single intake affecting combustion balance.

Propane has roughly 10% fewer BTUs than gasoline but has much higher octane (107+) so it's a wash. We average pretty close to 1:1 with propane winning the engine-wear battle.