Onan 5500 Generator

[kodiak_308]

Has anyone had any experience converting an Onan 5500 from gas to LP? Can it be done and what are some of the pros and cons?

[gery_L]

allcool wrote:

Jmo, not so sure/comfortable of 2, full 100# propane tanks inside your TH..? Can't you mount/plumb them under the TH, tucked in the frame somewhere." Maybe where the old genny gas tank use to be..? Sorry, just thinking out loud.

Allcool,
I haven't been out to the dunes in a while. Next season sounds good to me. Have a couple additions to the toybox that need to get sandy....

Alternate thoughts are always a good thing...
All very good points. I would also be concerned with the 2-100# propane bottles if they were loose in the garage. But with the stove and Refer right behind the front wall, I also plumbed the propane piping with a valved connection into the garage that a regulated crossover valve hose from the tanks can be attached to. Then the tanks are solidly attached to the inner wall of the trailer. No loose fireballs here.....
Gery

[allcool]

gery_L wrote:

allcool wrote:

gery_L wrote:

I care more for the cleaner burning exhaust and the better running at elevation, (as I hunt/camp in 7000 elevation, and that is where I use it the most).

Didn't the altitude adjustment lever on the carb work for you..?

Hey allcool,
....Randy... We've been to Glamis with the Zillas back in the day.... (AZ-ZILLA) Good to hear from you.

Yes it worked but was always overly finicky, and so was the choke setting for starting at altitude. Always needed to be fiddled with. Needed more choke at altitude, but when set, would be to much at low elevation (starts then dies). Local dealer and Onan reps couldn't get it right for both.
Choke isn't necessary now with Propane for starts, as the propane is injected in and air mixture isn't affected at elevation.
Along with dealing with old gas, and draining bowl after monthly start ups was getting to be a pain.
Then with week long stays for hunting trips in 10deg cold, needed more propane for heat, so it has been a Win-Win situation for me. (I carry 2-100# tanks in the garage of the Toyhauler).

Even with the 500 Watt power loss you stated, I have not noticed any power degrade. I have 3-15k AC units on the rig, and all can run with no problem (16amps each when running). Though, normally only run 2 at a time when in the AZ heat.

Gery

Hey buddy, good to hear from you, we got to meet up for a ride next dune season...

Earlier was looking at the Onan manual and found something that caught my attention. The Onan 4000 altitude adjustment range, went from sea level to 10,000'....
But, the Onan 5500 carb models max altitude adjustment went to only 5000'..?
The efi & propane 5500 models also went to 10,000'

So you probably did the only thing you could to run efficiently at the 7000' elevation. Convert to propane... Good move, with some other benefits like no more carb varnish build up for one. Carb varnish is a major pia to me.

Jmo, not so sure/comfortable of 2, full 100# propane tanks inside your TH..? Can't you mount/plumb them under the TH, tucked in the frame somewhere." Maybe where the old genny gas tank use to be..? Sorry, just thinking out loud.

Thats impressive you can run 3 a/c off a 5500, never tried that,,, would have to say thats full load...lmao.
My carb/gas 5500 HGJAB cuts out if I run my 2 a/c on hi, then try to use the microwave,,, no bueno for mine.

Sounds like your propane enriched Onan is pumping out the hp it needs.
Not that the genny needs it, but Propane does have a higher octane rating than gas. If the propane conversion kits have better afr calibration than the troublesome Onan gas carb that comes on the genny, I could see how the text book -10% hp rating of propane would be incorrect in some cases.
Actually from my experience, the slow unavoidable varnish build up in the normal RV use Onan carb will deteriorate the afr after years of use/storage, even with fuel stabilizers/additives/etc, and draining the carbs, and or running them once a month. The propane conversion has no such problem as far as I know...
jmo

[kodiak_308]

Thanks for the link and info. My unit stays at a place we have on the river a couple of hours away from home so doing a monthly run is often a problem. Not doing it has caused BIG problems. In talking with ONAN they seem to think that the typical toyhauler set up with the long run from tank to generator is subject to frequent fuel related problems. I don't use my generator often mostly just when DW and I stop for lunch or a rest when traveling but it's sure nice to have when you need it.

[gery_L]

allcool wrote:

gery_L wrote:

I care more for the cleaner burning exhaust and the better running at elevation, (as I hunt/camp in 7000 elevation, and that is where I use it the most).

Didn't the altitude adjustment lever on the carb work for you..?

Hey allcool,
....Randy... We've been to Glamis with the Zillas back in the day.... (AZ-ZILLA) Good to hear from you.

Yes it worked but was always overly finicky, and so was the choke setting for starting at altitude. Always needed to be fiddled with. Needed more choke at altitude, but when set, would be to much at low elevation (starts then dies). Local dealer and Onan reps couldn't get it right for both.
Choke isn't necessary now with Propane for starts, as the propane is injected in and air mixture isn't affected at elevation.
Along with dealing with old gas, and draining bowl after monthly start ups was getting to be a pain.
Then with week long stays for hunting trips in 10deg cold, needed more propane for heat, so it has been a Win-Win situation for me. (I carry 2-100# tanks in the garage of the Toyhauler).

Even with the 500 Watt power loss you stated, I have not noticed any power degrade. I have 3-15k AC units on the rig, and all can run with no problem (16amps each when running). Though, normally only run 2 at a time when in the AZ heat.

Gery

[fj12ryder]

Thanks gery_L, it's very much appreciated. This could move to the top of my "To-do list". I haven't had any starting issues yet even though I have only about 18 hours on it since we bought it in 2012. I do drain the carb after every use, so that may help. And keep Stabil in the gas in the tank.

[allcool]

gery_L wrote:

I care more for the cleaner burning exhaust and the better running at elevation, (as I hunt/camp in 7000 elevation, and that is where I use it the most).

Didn't the altitude adjustment lever on the carb work for you..?

[allcool]

kodiak 308 wrote:
Has anyone had any experience converting an Onan 5500 from gas to LP? Can it be done and what are some of the pros and cons?

In the Onan manual...
Fuel Consumption & Run Time
Fuel Consumption

propane
1.1 gal/hr(full load)
0.8 gal/hr(1/2 load)

gasoline
.07 gal/hr(full load)
.04 gal/hr(1/2 load)

You will lose about 500 watts of capacity going to propane since the btu output per gal of propane is less than gas and decrease hp slightly.

About 7gal in a 30lb propane tank.

jmo

[gery_L]

fj12ryder wrote:
If you prefer we can continue this in PM's. But I have a couple questions if you don't mind.

What does the conversion consist of?
Is it reversible?
Approximately how much usage time do you get from a 30# propane bottle?

The reason I'm asking is that I would like to do this if the propane run time is not much, much less than on gasoline. I use my tank infrequently and it would be nice not to have to worry about forgetting to drain the carb and having it gum up. I have space, unused presently, for a third propane tank that I could dedicate to the generator. Would this be a wise way to go about it?

Any info would be appreciated and I can use the PM if you'd prefer, but the 5500 is a popular OEM suppled generator and I thought it might be of interest to people other than me.

The link that I embedded in my reply below is the entire kit. This is the one that I purchased. It comes with a very good installation set of instructions, and the seller is very good at communication and can answer any set of questions you may have. He did for me when I was initially contemplating his system.

It is all bolt on, and removes the lower bowl of the Carb. But you will need to plumb the propane line to the regulator. I also put a 12volt inline switch/valve that is only open when the generator is running. The propane jetting screws directly in but the instructions state that it may be necessary to drill a 17/64 hole to match the SPUD. I did it a couple years age, and don't recall if I drilled or not. but have never desired to go back to gasoline.

As far as usage time, It is less than with gasoline, and I don't have any exact #'s because I use 2 100# tanks in the garage, and have never run the hours. I care more for the cleaner burning exhaust and the better running at elevation, (as I hunt/camp in 7000 elevation, and that is where I use it the most).
I would say not quite an hour/gallon.

An On-Line search can give you estimations. It looks like others see 10-12 hours for a 40# bottle.

Hope this helps your decision. I have never looked back.
Gery

[dcg9381]

christopherglenn wrote:
Generally propane makes less power then gas (the propane displaces air in the cylinder). Propane generators are also known for consuming more fuel then gas.

That's right:
1) It'll consume more fuel.
2) It'll make less power.

Perhaps:
1) Less tendency to overheat the fuel pump and stall.
2) No **** in the carb.

[fj12ryder]

If you prefer we can continue this in PM's. But I have a couple questions if you don't mind.

What does the conversion consist of?
Is it reversible?
Approximately how much usage time do you get from a 30# propane bottle?

The reason I'm asking is that I would like to do this if the propane run time is not much, much less than on gasoline. I use my tank infrequently and it would be nice not to have to worry about forgetting to drain the carb and having it gum up. I have space, unused presently, for a third propane tank that I could dedicate to the generator. Would this be a wise way to go about it?

Any info would be appreciated and I can use the PM if you'd prefer, but the 5500 is a popular OEM suppled generator and I thought it might be of interest to people other than me.

[gery_L]

I have a 40' 5th wheel toybox and I did it using this system I found thru eBAY (link below).
It may use more propane than gas, but does not have the high elevation issues that the gas did.
I carry additional 100lb tanks in the garage, and now the on board gas station is used for just the toys.
No regrets, and works perfect.

http://www.ebay.com/itm/IMPCO-PROPANE-CONVERSION-KIT-ONAN-MARQUIS-GOLD-5500-GENERATOR-5-5-HP-LP-GAS-5500-/170922881061?hash=item27cbcc3025:g:t~AAAMXQTghRK8wp&vxp=mtr

[christopherglen]

Generally propane makes less power then gas (the propane displaces air in the cylinder). Propane generators are also known for consuming more fuel then gas.