| Author | Message | ||
| Fred Wheeler (Freddie) (209.240.198.60)
Rating: N/A |
I am looking at a bus with a 6.5kw LP Onan genset. I would like to know the positives and the negatives of this type of setup. Also about how many gals or pounds per hr of LP gas would it use. The bus has a 100lb. bottle. I do not know how much Lp gas weighs per gallon to tell how many gals in 100lbs of gas. Any help would be much appreciated. Thanks Fred | ||
| FAST FRED (209.26.115.209) Rating: N/A |
If you live in an area , or like to travel to an area where the Air Cond is NOT on 24/7 , propane is the best choice for a gen set. If your just outside Bagdad the Diesel would be better for less fuel comnsumption. The reason Propane is chosen for the best RV's is many. The exhaust won't poison you , or the folks in the next tent site. The exhaust note is easiest to quiet. Stopped ,the fuel will evaporate , so the dirty carb problems in an unused gasolene set will never hassel you. There easy to get started in the real (minus zero) cold , even with a pull rope. A tiny diesel needs block heaters , manifold pre heaters and a big Charged! set of batts, for the attempt. Not a chance with a pull rope. The fuel burns so clean that the oil stays fresher & the combustion is clean enough that most Propane will outlast the lawn impliment diesels used in many gen sets. Many propane are air cooled, (which makes the instalation more dificult) but they heat up faster so wear out much less if used improperly (turned on for 4 min for the microwave, then off). Biggest downside is the fuel costs a bit more than diesel , but the cheaper , less frequent maint will make up for it, as may the longer life. My guess is operation about 300 hours a year is the cut off, above that just get a little diesel & leave it on like a reefer truck , (they , unlike most RV'S actually do get good life from their diesels.) The other hassle is that the larger Propane units only create about 10KW , so its never enough for the TEC boys.Barely enough to run a range on. Your 6.5 will run two old inefficent air cond , or basements , and still have some left over for batt charging or TV etc. I would assume your refrigerator,furnace , hot water , & cooking will all use this silent source of energy. Way to go if your a big time boondocker, or standard RV user. FAST FRED | ||
| Phil (204.89.170.126) Rating: N/A |
Propane weighs about 5 pounds per gallon but a 40 gallon tank only holds about 35 gallons due to required air space. A new Onan 6.5 LP generator uses (per Onan's/Cummins website www.onan.com) 3.5 pounds per hour at 1/2 load and 5.3 Pounds per hour at full load. I have had both an 6.5 LP Onan and a 7.5 Onan Quiet Diesel (current). I prefer the diesel as I am more willing to leave it running due to the fuel consumption. Fred's points are all valid and I can't justify from economics the use of the diesel but it is much less hassle keeping the diesel tank full than having to refill the propane. Also, the diesel has always stated with no problem even in winter, maintainence has not been a problem and the Onan is serviceable from the bottom. Without the generator running off the propane I only fill it two or three times a year and that is with using the heat about every other weekend up here in northern New York winters!! I find getting propane when I am local to be a pain in the a**. On the road it is easier at places such as Flying J stations but the price is all over the board. locally I have paid as much as $3 a gallon or more and rarely less than $2. | ||
| Scott Whitney (66.82.9.18) Rating: N/A |
I have a 6.3 Onan LP genset. I like it. Runs pretty quiet. Reliable so far, but I only have 147 hours on it. I would have preferred diesel, but could not afford a new one and did not have the space to put one. So the air cooled propane unit works well for me. But it makes me a meiser on running it since propane is expensive. Maybe that is a good thing. If you want to boondock a lot or run A/C 24/7, you will want a diesel unit. For sporadic, occasional use, the propane is probably best. Scott | ||
| Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A |
And for me, I'd never go diesel. I've got a 7Kw Onan Marquis that I converted to propane and I love it. But I have to admit I have a thing for propane. My rig has a 110 gallon tank, so running out of the stuff isn't a problem, and I buy it here at home delivered for a buck and a half a gallon max, usually more like $1.20 As Fred says, propane is about the best thing you can do to an engine... as a matter of fact, if you convert a new "gasoline" engine to propane and don't put 50 hours on it first with GASOLINE, the propane is so easy on the engine that it will never "break in" the rings, ie the hash marks left from lapping the cylinders will never go away, the oil control rings will never seat, and it will burn oil forever. Engines that are "made" for propane are broken in mechanically, usually by some method like putting a tbsp full of BonAmi mixed with some oil into each cylinder and rotating the engine over 20-30 times, then cleaning it all out and send it on it's way. No lie! I took a week-long intensive propane school from Impco, and that's how they do it! I've seen an engine with 250,000 miles on it, propane, and there was so little wear that the hash marks were still on the cylinder walls!! So what's my point? Engines running on propane rarely need oil changes, run virtually forever, never flood, always start when you need them, never gum up, and their exhaust smells good to boot. Yup, it's way cool stuff for engines!! The minus points? Diesel has about 10% more energy per gallon than does gasoline which has 10% more energy per gallon than does propane, so if it's space you need to save, you're going to need aproximately 20% more tank volume per hour with propane than with diesel. But that's about the only negative when I consider "my way"!! Cheers Gary | ||
| FAST FRED (209.26.115.194) Rating: N/A |
Depending on where you live , fuel cost can be a big variable. Propane is cheap in Texas , but dear in other places, a diesel on house fuel will always be cheaper to run than Propane. FAST FRED | ||
| Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A |
Too bad this is no longer happining- back in the 80's the REASON I converted my Superior pusher to propane (for the ENGINE!) and stuck 325 gallons of tank on it was that I could drive to mexico 30 miles away and buy the stuff for ten cents per gallon!! The bus's wonderful 6MPG SUCKED! But, I logged almost 100,000 miles going back and forth to San Fransisco to the Ren-Faires, costing me $20 or so per 1200 mile round trip! But in the real world today, NEVER convert a gasser to propane if you want to save money on fuel (although it was neat to see the engine oil looking exactly the same -pristine clean- as the day I put it in, 50,000 miles later!!) Yup, those were the days...  Cheers Gary | ||
| john marbury (Jmarbury) (65.100.118.38)
Rating: N/A |
Gary, Where is the best place to look for converting a gas genset over to propane? Is it cifficult to do? John | ||
| Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A |
John, I've converted 6-7 engines to propane and it's simple to do. There are three options to consider: (1) Buy the factory parts and install them. It's the most expensive but easiest to do. Not my cup of tea. (2) Buy a kit that installs a secondary propane venturi between the existing carb and air cleaner. Again it's an easy job but starting the engine remotely can be an issue, because it's in front of the choke and as such there's no vacuum at the venturi to suck propane during startup. The fix: the regulator can be purchased with an internal 12 volt "prime" solenoid- I simply hook that to a pushbutton located with my remote control. Hold the button down, count to three, then start the engine. A second benefit to this type of kit is that the engine will still run on gasoline. Dual-fuel!! (3) Modify the carb permanently by drilling out its main jet and installing a dedicated conversion kit. It's definitely the best way to go but a bit more involved, because you're modifying the carb and once done, you can't go back. This type of conversion works very well, usually will produce more power than option 2's method, and starts just fine without requiring a prime solenoid because the engine's original choke still functions. I've done most of my engines this way and like it the best. .................... To do #1, of course just call Onan or whoever made your genset and order the parts. Usually about $400 worth. For #2, go to http://www.otherpower.com/otherpower_propane_convert.html Email the guy and buy a kit from him (it's not in his online catalog) - it's about $100 or so, and be sure to also get the 12 volt low pressure solenoid valve that is a required safety shutoff. The electrical connection to this valve would hook up where your electric gasoline fuel pump now connects. This kit is a "low pressure" withdrawal kit which I will explain later. For Kit #3, go to http://www.propane-generators.com/ and look at their "type 1" or "type 3" kits. They also have a type 2 kit which is the same as the one mentioned above, but the otherpower guys have better prices for that style. REMEMBER with any kit, on an RV it's a requirement to have some form of safety shut-off. Some regulators do this internally using a vacuum line to the engine. Some require an exernal solenoid running on 12 volts. Just make sure one way or the other that you have provided for this function in your system!! ............ Now a few other things to make it even more confusing! Depending on how you want to draw propane out of your tank, you'll need to make more decisions. (a) You can take the fuel out of your tank as "high pressure" meaning that the regulator in the kit you buy hooks directly to the VAPOR outlet on your tank, and runs at tank pressure (around 200psi on a warm day) In this case you'd buy a "high pressure" kit (b) A "low pressure" kit. In this method, since you probably already have a primary regulator on your RV system that provides propane at less than 1-PSI to feed your stove, fridge, heater, etc, you purchase a "low pressure" kit (the one from Otherpower is low pressure only) and install it in your existing low pressure system. The only catch is that your primary regulator must be large enough to accomodate the generator's rate of gas usage at full power. I've found this to not be a problem even when using a simple BBQ regulator. I personally like this kit the best simply because I like high pressure propane lines to be as short as possible, not running all around my bus. This way you mount your primary regulator very close to the tank, and then only low pressure lines are running around to the genset and all the appliances. Much safer and less prone to leaking... 3/4" Iron pipe works fine with stainless steel flex hoses for the last couple of feet to the genset. (c) Liquid propane withdrawal systems: Forklifts use this type of system because their tanks are small and their engines are large and use a lot of fuel. In this system, Liquid propane is drawn out of the tank, and vaporized in a remote water-cooled vaporizer, then sent to the engine's regulator. The added complexity of this system is sometimes necessary if your tank is small- reason being that on gaseous withdrawal systems, the propane is boiling and turning to gas within the tank, and if the tank is too small for the rate that you're withdrawing fuel, because there is not enough tank surface are or mass to make up for the heat required to boil the propane, it will refrigerate and freeze, and quit providing fuel!! With a tank of 40 gallons or larger this shouldn't be a problem. But I've made BBQ gallon tanks freeze up with my 7KW genset running full bore. I doubt it will really present a problem with a 35-40 gallon or larger tank, but I thought I'd explain why it's used anyway. Hope that helps Cheers Gary | ||
| john marbury (Jmarbury) (65.100.118.38)
Rating: N/A |
Gary, thanks for the info. I'll read it over and over till I understand it. I have no system installed yet. I do have the gas genset but it's not installed. John |