Converting Onan from LP to gasoline

[howardwheeler]

I have a Onan 5500 propane generator in my fifth wheel. It eats propane at a prodigious rate. Has anyone converted from LP to gasoline? What I'd actually like to do is make it dual fuel so I could hook up auxiliary gas tanks when I need an extended run. I can handle a few five gallon gasoline tanks but dry camping with only propane simply does last long enough.

[Lantley]

howardwheeler wrote:
I believe there's some confusion. The standard tanks on fifth wheels are 30 lbs not 30 gallons. The Open Range units have 4 20 lbs tanks not 4 20 gallon tanks. A twenty pound tank doesn't even hold five gallons. I think it's somewhere between four and five gallons. I wish I could carry 60 or eighty gallons, but I'm afraid it's pounds not gallons that fifth wheel capacities are measured in.

I stand correct on the gallon vs. pound however the physical tank size didn't change.
Bottom line is just get an extra tank. If you currently have 2-30# tanks get a 3rd or even a 4th. Which will give you 90# or 120# total. I think lp is still more convenient and reliable than dealing with gas cans.
Is your thought to have a built in gasoline tank or do you plan to use portable gasoline tanks and set them up each time you use genset?

I guess the biggest issue is how many hours per day do you need to run your genset. How much gas required vs. how much additional lp required.Once you determine the amount of fuel required it may be obvious as to which fuel source will be best.
Are you trying use it 24 hours a day? 8 hours a day? How many continuous days?

[wolfe10]

But, since you can only fill a propane tank to 80% of capacity, those capacity numbers would be lowered by 20%.

[camperpaul]

FWIW:

At 60°F, propane weighs 4.2 lbs. per gallon.

Therefore:

A 20 lb. tank holds 4.76 gallons.

A 30 lb. tank holds 7.14 gallons.

A 20 gallon tank would hold 84 lbs. of propane.

A 30 gallon tank would hold 126 lbs. of propane.

[howardwheeler]

I believe there's some confusion. The standard tanks on fifth wheels are 30 lbs not 30 gallons. The Open Range units have 4 20 lbs tanks not 4 20 gallon tanks. A twenty pound tank doesn't even hold five gallons. I think it's somewhere between four and five gallons. I wish I could carry 60 or eighty gallons, but I'm afraid it's pounds not gallons that fifth wheel capacities are measured in.

[MEXICOWANDERER]

First convert it to gasoline. When that's done...

Buy a "dual fuel" kit which sits atop the carburetor. Your local Onan repair shop can help with the 1st the 2nd part go to your local propane distributor the one that has a repair shop out back.

[Lantley]

howardwheeler wrote:
Maybe I'm wrong but the standard cylinder is 30 lbs or around 6 or seven gallons. I've never heard of a fith wheel with an eighty gallon propane capacity. They do make them with 80 pound capacity, usually with four 20 lbs tanks. Eighty gallons would be sufficient but I couldn't put anything that big in my unit.

Most (maybe all?) Open Range 5'ers come with 4-20 lb. tanks from the factory. I understand you may not want to carry extra LP, But carry extra LP is just as easy and less messy than carrying gas cans.
I agree finding gas stations and filling tanks would be easier with gas

[SaltiDawg]

Dumb post removed by author. :B

[howardwheeler]

I'm not finding a conversion kit for propane to gasoline. I founds lots of gas to propane. Do you have a link?

[howardwheeler]

Maybe I'm wrong but the standard cylinder is 30 lbs or around 6 or seven gallons. I've never heard of a fith wheel with an eighty gallon propane capacity. They do make them with 80 pound capacity, usually with four 20 lbs tanks. Eighty gallons would be sufficient but I couldn't put anything that big in my unit.

[camperpaul]

Onan has a tri-fuel conversion kit (gasoline/natural gas/propane).

Google it.

[howardwheeler]

Right now its just hooked up to the two 30 lbs tanks on the 5th wheel. I was hoping to be able to run it also off gasoline when I need it go extended times. I know they make dual fuel units, but I have not found a conversion kit. I know propane is much better from a maintenance point of view, but it just blows through propane, and gas cans are a lot easier to fill and transport than taking out the propane cylinders and lugging them to the local propane dealing, if there's one around.

[Lantley]

I also have a Onan 5500 LP and I agree it uses lots of propane. As mentioned above propane burns much cleaner than gas. Propane gensets tend to be more reliable than gas because you do not have to deal with carb or fuel issues that plague built in gas gensets. Have you considered simply carry more propane vs. converting to gas. My rig came factory equipped with 80 lb propane capacity.
A more viable solution maybe to plumb one or two additional propane tanks to your genset.

[CA_Traveler]

howardwheeler wrote:
I can't run the generator more than a few hours without it sucking a 30 lbs. cylinder dry.

Is the gen running to spec on propane consumption? I suspect any conversion will be big $ and may involve more than just the carb.

Have you considered swapping it for a gas gen or a bigger propane tank? 30 lbs is a very small tank.

[dave17352]

howardwheeler wrote:
I can't run the generator more than a few hours without it sucking a 30 lbs. cylinder dry.

Hum I have 3500 Generac I wounder how long it will take to run out my 30 pound bottle. I have run it a couple hours with the ac so far on one bottle. I think I will run out that bottle with the AC on and see what I come up with.