Barthmobile Portal
Generator conversion from lp to Diesel
08-31-2013, 08:52 AM
Al and BBGenerator conversion from lp to Diesel
Am considering changing my lp onan generator to a diesel one. Has anyone got experience in this? Would appreciate any help.
AlandBB
08-31-2013, 01:17 PM
RustyWelcome to the Forums!
I converted to gasoline; my coach has a small (40 gal) diesel tank, and there was room behind for a 24 gal gaso tank. I do a fair amount of dry camping, and the Honda is far more economical and quiet.
The conversion was pretty straightforward. I made ramps to elevate the front so the gensets could clear. I used an ATV lift to get most of the height, then used threaded rods for the final lift, taking a few turns on each, then replacing the rods with the mounting bolts one at a time. I did have to fabricate new mounts.
I used the existing wires for the inside control.
Rusty
"StaRV II"'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP
Nelson and Chester, not-spoiled Golden Retrievers
Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering. - Arthur C. Clarke
It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields
08-31-2013, 02:26 PM
wally povajnukquote:
Originally posted by Al and BB:
Am considering changing my lp onan generator to a diesel one. Has anyone got experience in this? Would appreciate any help.
AlandBB
Greetings Al what are your reasons for taking on this expensive endeavor- my unit came with a propane unit that is clean burning, cheap to run,and does not rely on using my engine fuel.Wally proud owner of 34ft monarch van-ile.
08-31-2013, 05:08 PM
Al and BBThanks for the responses. not sure I want or need to, I am new to the RVing world and it just seemed to be logical that the generator use the same fuel source as the engine. Your response is what I needed to hear.
09-01-2013, 12:09 AM
Mogan Davidswitch would be poor bang for the buck.
Huge cash outlay.
No significant savings.
No greater resale.
Many motorhomes use different fuel for propulsion and genset.
09-01-2013, 10:58 AM
Marvin+DorisWe have a Onan LP genset. It is old but it works fine, so until it quits no reason to replace.
1995 Bluebird Wanderlodge Widebody
S60 Detroit 42'
Former owner 1989 Barth Regal 25'
09-01-2013, 11:22 PM
Mogan Davidquote:
Originally posted by Kevin:
quote:
significant savings

There would be significant savings if the diesel were running on WVO Waste Vegetable Oil.

Many older diesels run well on just 50/50, without removing the glycerin.
So, Kevin, how long (like hours of operation) do you figure it would take to recover the cost of removing the LP genny, and installing a diesel genny, before realizing any "significant savings"?
09-01-2013, 11:46 PM
RustyI replaced mine due to three reasons:
1. Noise. The Honda liquid-cooled gaso is anywhere from 8db to 16db quieter than the LPG Kohler, depending where measured..
2. Reliability: The Kohler was cranky to start
3. Economy: At the Nebraska Star Party, I would have to refuel the LP twice in Valentine, 35 miles distant. With the Honda, the same volume of fuel lasted the entire week. Gasoline was available 8 miles away.
If I were rarely dry camping, the cost and effort wouldn't have been worth it, but in my case, with 50-80 hours on the genset every year, yes. And having to locate a propane dealer when I ran out (no stove, HW heater, reefer, or genset), the gaso Honda wins hands-down...for me.
Rusty
"StaRV II"'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP
Nelson and Chester, not-spoiled Golden Retrievers
Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering. - Arthur C. Clarke
It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields
09-02-2013, 12:32 AM
MWrenchI probably use my generator more than anyone on this board. I have put 1300 hours on it since 2006. It is a propane unit. I will use on average 30 gallons of propane on a 3 day race. I run all the computers and A/C for 3-5 days at least 8 hours a day. I have to plan ahead for propane purchase but hasn't been too bad.
I analyzed the cost of converting to diesel or gas and I could not justify a change. I have had very little trouble with the unit and it is fairly quiet. Loudest noise is the cooling fan and of course low pollution.
I will make a change one of these days but it will be to an inverter type 8KW diesel and incorporate the inverter with the generator/battery set.
It is very hard to financially justify any change unless the unit has severe mechanical or electrical problems.
Ed
94 30' Breakaway #3864
30-BS-6B side entry
New Cummins 5.9L, 375+ HP
Allison 6 speed
Spartan chassis
K9DVC
Tankless water heater
09-02-2013, 01:11 AM
wally povajnukquote:
Originally posted by Rusty:
I replaced mine due to three reasons:
1. Noise. The Honda liquid-cooled gaso is anywhere from 8db to 16db quieter than the LPG Kohler, depending where measured..
2. Reliability: The Kohler was cranky to start
3. Economy: At the Nebraska Star Party, I would have to refuel the LP twice in Valentine, 35 miles distant. With the Honda, the same volume of fuel lasted the entire week. Gasoline was available 8 miles away.
If I were rarely dry camping, the cost and effort wouldn't have been worth it, but in my case, with 50-80 hours on the genset every year, yes. And having to locate a propane dealer when I ran out (no stove, HW heater, reefer, or genset), the gaso Honda wins hands-down...for me.
hi Rusty I guess I am lucky someone installed a 60 gallon in my unit.wally -34ft monarch van-isle.
09-02-2013, 07:38 AM
Steve VWI put in a Honda to replace the Kohler.
The Kohler had only 300 hours on it, but it was loud, it shook the whole coach and was 7kW which is about twice what I need. Used more gas than needed.
There is no financial incentive... the Hondas ain't cheap and the Kohler ran OK. However, the Kohler is now my permanent house backup (I had a portable 4 kW but the Kohler is better at 7 kW so it still has a purpose.)
The Honda is so quiet you can barely hear it. If you are inside the coach with AC or microwave on you can't hear it or feel it at all.
The quiet, reliability and fuel economy work for me.

9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
09-02-2013, 08:34 AM
wally povajnukquote:
Originally posted by Steve VW:
I put in a Honda to replace the Kohler.
The Kohler had only 300 hours on it, but it was loud, it shook the whole coach and was 7kW which is about twice what I need. Used more gas than needed.
There is no financial incentive... the Hondas ain't cheap and the Kohler ran OK. However, the Kohler is now my permanent house backup (I had a portable 4 kW but the Kohler is better at 7 kW so it still has a purpose.)
The Honda is so quiet you can barely hear it. If you are inside the coach with AC or microwave on you can't hear it or feel it at all.
The quiet, reliability and fuel economy work for me.
greetings Steve with all this talk of Honda,is this a drop in situation?seems that that the 7kw was replaced by a 4kw.Does Honda make a 7kw?wally 34ft monarch van isle
09-02-2013, 04:06 PM
Steve VWNo drop in that's for sure.
This all started because the OEM panel Freon 12 engine AC system didn't work. It is all gone. I wanted to be able to run AC on the roll so I need the genset.
I don't have any big inverters, etc. Just AC and microwave. The forward OEM roof AC just died so I replaced it with a powersaver model. Didn't need the noisy, shaky, behemoth 7 kW Kohler (not bad for my house, though!)
Then it gets interesting. I wanted a smaller, less noisy, more efficient genset. This pretty much points to Honda.
Problem: Honda used to make nice 4 kW RV genset. They don't anymore. They do make a really quiet "portable" 3 kW inverter model with electric start. 145 lb Honda, 350 lb Kohler. Hmm...
The Honda 3000 is air cooled but not made to run in an enclosed compartment. Hmm...
The Barth gen compartment has a big hole in the bottom tray and large vent screen out the side, enough air for the Kohler...
The Honda fit well in the gen compartment. It pulls cool air from below. I made a plenum to direct the cooling/exhaust air out the side screen. Also 2 additional muffin exhaust fans are mounted on the side screen to circulate the air through the compartment. I have run it with the compartment closed for an hour or so, running the AC on a hot day. Compartment remains cool.
The key switch is wired to the driver panel control for remote start and stop. On the road, you can't hear it running and the roof AC is wonderful.
Only downside so far, I haven't rigged a solenoid to allow for remote choke control for cold starting. Also have not yet tapped into the Barth fuel line. The Honda runs all day on one tank, anyway. When I get done I will post a thread with the whole mod.

9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
09-10-2013, 08:20 PM
Richard_MuiseAnyone have pictures of a Kohler to Honda conversion???
R.P.Muise 1994 Breakaway/Cummins 5.9/Allison transmission/Spartan Chassis
09-10-2013, 08:30 PM
Rustyquote:
Originally posted by Richard_Muise:
Anyone have pictures of a Kohler to Honda conversion???
Yep.
Rusty
"StaRV II"'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP
Nelson and Chester, not-spoiled Golden Retrievers
Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering. - Arthur C. Clarke
It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields