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Discussion Starter · #1 ·
We've got several irrigation motors that are 4bt, 4bta, and 6bt. We were wondering how much, if any, money we would save by blending propane into them? Also what does it takes to convert them? With diesel as high as it is, it costs a fortune to fill each of them up 3,000 gallons at a time. These motors are bone stock and run all day long at the same rpm.

Thanks,
CJ
 

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There are certainly guys on here who know lots more than I do, but here's my $0.02:

Your cost up front would be pretty high (though probably not as bad as buying 3000 gals of diesel in one shot :eek:): Each motor has a 3000 gal. fuel tank? Or 3000 gallons fills up all of them? At any rate, you'd have to buy propane tanks, then fill each of them up (to 80% capacity) @ somewhere in the neighborhood of $2.60/gal.

As much as you run those things, I'd say it's financially feasible to do it. You'll pay off the propane setup pretty quickly running that many hours. Guys are gaining what, 10% fuel economy running propane? 15%? Propane's obviously cheaper than diesel, and the way I think about it is like this: For every gallon of propane you buy, that's 1.1 - 1.5 gals of diesel you don't have to buy. So you begin paying it off instantly at the rate of $2/gal. If I was guessing, I'd say you'd pay off your investment and start putting money back in your pocket in the first 3000 gal diesel fuel-up.

Same as with an on-road setup, though, you want to make sure your EGTs aren't too high.
 

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Discussion Starter · #3 ·
It's 3,000 gallons per well and they get filled up several times throughout the summer. The tanks are free with a contract through the CO-OP. If I contract enough propane, I can get it for $1.85. What does a kit cost to convert it? With it properly installed, is there a chance it could do damage to the motor?
 

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i have converted several to natural gas off the top of my head i think the ignition point of propane is two low to work but propane injection will greatly reduce your fuel use it helps combustion big time and off the shelf kits are available from ats and a dozen others
 

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If you're pretty mechanically inclined, you can build your own conversion "kit" more cheaply than you can buy one. Search the forum; someone on here posted how they built their own.

As for damage to the motor, I'd say proper installation and calibration makes it highly unlikely. The only risk I'm aware of (and I'm by no means an expert) is adding too much propane to the combustion process, which would run your exhaust gas temps too high, which can burn up your turbo. Since you're squirting propane for mileage rather than for power, your flow of propane should stay pretty low, but you're still going to want to tap in a pyrometer and check EGTs. It may take a little experimentation for you to get your system calibrated just right for your needs.
 

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Since your engines run the same RPM, it should be pretty easy to rig something up and get it flowing correctly. The correct amount of LPG used to fumigate the intake on a diesel will make the engines run more efficiently. The propane will ring out some extra power out of the fuel oil. Here is some good reading on the topic..

LPG (Propane) Fumigation for Diesel Engines
 
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