Hi guys, I haven't been around for a while. Life got busy...
So, I'm thinking I should be able to run this engine on propane. Has anyone here done this? It sure seems possible, although I could see a couple of issues like lubrication that may cause a problem. I have plenty of propane that could be earmarked for generator use if necessary, having an alternate fuel source would be a good thing.
well first off propane doesn't have the btu's like diesel, and also wouldn't the injector pump die a premature death?
Hi Fellas. If propane is cheaper than Diesel, it can be bled into the intake in a controlled manner reducing the diesel/hp ratio. This way the injector stays lubed. In Australia large trucks use LPG/Diesel combo setups commonly. Cheers, Derb.
Quote from: Derb on March 30, 2012, 01:43:38 AM
Hi Fellas. If propane is cheaper than Diesel, it can be bled into the intake in a controlled manner reducing the diesel/hp ratio. This way the injector stays lubed. In Australia large trucks use LPG/Diesel combo setups commonly. Cheers, Derb.
This is the easiest way to do this. Remember, the governor that controls your engine RPM and the output frequency regulates the fuel output by the injector pump. IF you went total propane route, you would need a governor and propane fuel control system to maintain a constant engine RPM. If you bleed propane into the intake at your lightest load till the governor lever(the one with the spring on it) NEARLY reaches the shutoff position, then the governor will add diesel fuel to handle any loads beyond that point. that way the governor still maintains a constant RPM under varying loads, it just does it using a fraction of the diesel fuel it normally would.
Of course if for some reason ALL the load goes away, such as a popped circuit breaker, the engine will overspeed as the propane delivered for that minimum load is way more than what is needed for no load. So any type of system that adds propane realy needs an overspeed sense circuit to cutoff the propane in the event of an overspeed condition... This could be as simple as a solenoid valve and a switch that can be activated by the existing governor lever when it completely closes the IP rack, which would happen if the engine went above the governed RPM...
Just thinking out loud, I wonder if liquid propane could be fed through the injection pump? If it could would it burn?? Would it provide enough lubrication for the pump??? Purging the system could be tough though.
Quote from: Ronmar on March 30, 2012, 08:10:54 AM
Quote from: Derb on March 30, 2012, 01:43:38 AM
Hi Fellas. If propane is cheaper than Diesel, it can be bled into the intake in a controlled manner reducing the diesel/hp ratio. This way the injector stays lubed. In Australia large trucks use LPG/Diesel combo setups commonly. Cheers, Derb.
This is the easiest way to do this. Remember, the governor that controls your engine RPM and the output frequency regulates the fuel output by the injector pump. IF you went total propane route, you would need a governor and propane fuel control system to maintain a constant engine RPM. If you bleed propane into the intake at your lightest load till the governor lever(the one with the spring on it) NEARLY reaches the shutoff position, then the governor will add diesel fuel to handle any loads beyond that point. that way the governor still maintains a constant RPM under varying loads, it just does it using a fraction of the diesel fuel it normally would.
Of course if for some reason ALL the load goes away, such as a popped circuit breaker, the engine will overspeed as the propane delivered for that minimum load is way more than what is needed for no load. So any type of system that adds propane realy needs an overspeed sense circuit to cutoff the propane in the event of an overspeed condition... This could be as simple as a solenoid valve and a switch that can be activated by the existing governor lever when it completely closes the IP rack, which would happen if the engine went above the governed RPM...
Ronmar,
I am currently fogging natural gas via a needle valve into the intake of my 6/1. It is setup up so that at 1500 watts the fuel rack is almost completely closed with just enough diesel to keep the engine running with no load. When the load increases the rack opens as you said, but, if the load goes completely away the engine will not overspeed. When the engine tries to over speed the governor just closes the rack more until there is not diesel going into the engine and the natural gas will not ignite without it. As the engine slows below the governed rpm the rack begins to open again keeping the engine running. the only thing i have seen when the load is dropped the engine actually doesn't fire on each compression stroke because of the excess natural gas and the rack closed down so far.
Cool! Then it becomes a Hit 'n' Miss diesel! ;D
Ron
Interesting discussion, thanks for the input. I think that for my needs, I could just use the propane directly to run a propane fridge. Oh well, it was worth asking.