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Extreme Veteran
 
Location: Scottsdale, Aridzona | Break even for a Diesel Engine Conversion for a FMC Motohome ?
Two GREAT current examples Stephan's #1046 and Len's #1027 ! Great power/torque/mileage/range/driveability/miles between fill-up !! And GREAT workmanship by all involved !!!
Stephan's has demonstrated a solid 14 MPG, and Len's will certainly get at least that, perhaps more. Many 440 gasoline powered FMCs get 7 MPG, rarely more, often less.
Current nationwide gasoline is $2.159/gal and diesel is $2.348/gal ( http://www.eia.gov/petroleum/gasdiesel/ ).
If converting our favorite FMC to a Duramax Turbo engine with a 5 speed OD transmission can be done for $11,000 doing all the work "yourself" including some "send out work" as suggested by Len above, then how many miles have to be driven to break even for the CO$T of the complete conversion ?
Please see - http://www.thefitrv.com/rv-tips/gas-vs-diesel-a-calculator-and-my-t...
The calculator there requires something input to the DEF box, so put in $2 for the cost of diesel and put the change (.348¢) and the same fuel mileage for the DEF as the diesel fuel mileage to make it work. (can't divide by zero) (Diesel Exhaust Fluid is required on current diesel engines, but NOT on "your" FMC Conversion)
The actual spreadsheet and the formula used is given as a link on the website, or you can just put in different values of your own choosing, including the "engine conversion" cost.
Break even miles for a $11K diesel engine conversion (doing all the work yourself) of a FMC at today's (8/2/16) gas and diesel cost is 78,000 miles.
How many miles will you drive your FMC this year, decade, lifetime ? You can't ignore the power/torque/mileage/range/driveability/miles between fill-up, but looking at that 78K miles for break even brings up other thoughts . . . the first is something about a $400 saddle on a $20 mule . . . but NOBODY WILL BEAT YOU TO THE TOP OF THE HILL !
Zoom ON ! Lou #120
Edited by hemi354az 2016-08-02 2:18 PM
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Elite Veteran
Location: Oceanside, CA | I agree with all that.
There is no break even(IMHO), for me it was an issue of capability. I need to reliably/easily tow 7000lbs and I wanted a vintage motor-home that had modern drive-ability. That coach doesn't exist in the market so I have to build it.
The only way to even some of it(cost) out is if you buy(or have) a coach that already needs and engine and or trans replacement and get a good deal, starting with only $5k in the game and adding $11k to do the swap puts you in pretty good shape if you hold on to it for awhile and get some good use. If you already own the coach and are being faced with spending $2000 for an engine rebuild and $1000 for a trans rebuild for stock power train, it may make the leap a little shorter.
Doing this swap to a coach that is in good stock condition and providing good service would be a tough thing to do... in the end you just really have to want the power and be willing to pony up for it..
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Extreme Veteran
Location: Scottsdale, Aridzona | SOME PONY ! More like a Thoroughbred ! Again, just great work !
Lou #120 |
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Elite Veteran
Location: Oceanside, CA | Great example of a good donor, this is the same dismantler I bought my package from. You could probably get this in the $4800 range..
http://www.ebay.com/itm/USED-2003-CHEVY-SILV-LB7-DURAMAX-171k-LIFTO...
And here's a higher mileage LBZ...note the price jump
http://www.ebay.com/itm/2006-Silv-C2500-6-6-LBZ-DIESEL-DURAMAX-LIFT...
Edited by LCAC_Man 2016-08-02 3:25 PM
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Expert
Location: Cottage Grove, OR | Lou's number is about as correct as one can calculate a conversion dollar cost recovery at today's fuel prices. When I started my conversion project, fuel prices were significantly higher, but the calculation still resulted in a mileage number in the 40-50,000 range.
But all of this "cost recovery" calculating begs the question of "What is the cost recovery calculation of buying any motor home?" One has to remember that Return On Investment or Cost Recovery in discussions about motor homes seems a bit out of place to me. Both the original cost, maintenance costs and the cost of my conversion are coming back to me in the form of pleasurable travel.
I have put about 75,000 miles on my coach since I bought it. I think I have gotten a much higher return on my investments, original plus subsequent, than any owner that has only put limited miles on their coach. It's the total dollars divided by the miles of smiles that count in my book. |
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Veteran
Location: Houston, Texas | We agree with you Mr. Stephen, is the "miles of smiles" that can be obtained and maintained,
and for us, one of the most important fact is that now you can travel about twice as many miles
from now on.
Rico & Carmen
397 |
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Elite Veteran
Location: Oceanside, CA | Passenger side structural/anti-sag mod complete and foamed:
http://www.fmcowners.com/mbbs22/photos/show-album.asp?albumid=127&p...
Time to get the panel back on. |
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Veteran
Location: Olympia, Washington | Len:
Is the drivers side fiberglass panel in 2 pieces on your coach? #506 runs from the drivers door to the engine 'cover' in one piece. In your anti-sag mod did you remove aluminium framing first and replace it with steel? How did you go about fastening the new steel to the existing aluminium structure? You are doing an awesome job keep up the good work. |
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Elite Veteran
Location: Oceanside, CA | George,
It's a single piece from the door to the engine bay covers.
Yes, I removed the outer boxed portion of the existing aluminum structure leaving just "flatbar" attached to the interior skin. I used #14 self tapping screws (I pre-drilled to make life easier) to connect the steel to the aluminum and then tack welded the heads so they don't ever work loose. I used 1.5" square tube because it fit well, in the high load areas I used 3/16" wall and then 1/8" everywhere else to keep the weight down.
The passenger side is by far the most important, it's where all these coaches seem to sag the most. It makes sense with the engine biased to that side and the frame rail being miter cut for the angle removing some of its strength.
Building in new/improved strength isn't hard. Counter-acting/removing any existing sag is really really hard, that frame rail has had years of being in that sagged/bowed shape so that's its new normal. Even with all I did on the passenger side I still have about 3/16" sag/bow,
with the new structure I doubt that will ever increase but I had been shooting to eliminate it completely. When I started it was well over an inch sag from the door to the rear of the coach.
Edited by LCAC_Man 2016-08-06 9:15 AM
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Elite Veteran
Location: Victoria, BC. Canada | Yeah, ditto what George said: Great work and thanks again for sharing this cool project with all of us, Len!
I haven't checked my coach for the infamous 'Butt Sag' yet but my butt sure is starting to sag! Welcome to the 60's Terry...
We all know these coaches had the engine canted starboard 10-15 degrees purposefully to balance the rear load of the big-pig Onan they came with. Good foresight there. Another potential reason for more droop on the pass side could be attributed to the opening for the entry door and the lack of horizontal framing there.
If/when I get around to my engine swap I'll do some measurements to see if #846 still has a flat chassis.
Terry
#846 |
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Elite Veteran
Location: Oceanside, CA | Terry you don't even need to measure, just stand at the rear of your coach and sight line along the rub rail, it shows it pretty clearly, also every coach I've seen has the "bulge" just forward of the rear window, that's a sure sign of sag.. |
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Elite Veteran
Location: Oceanside, CA | George,
I just reread your post, on the drivers side it is a two piece panel, the split is between the bathroom and kitchen. There's a trim strip there that covers the seam. |
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Elite Veteran
Location: Victoria, BC. Canada | Just had a quick lookie at mine and yes there is a bit of a bulge in the rub rail, just ahead of the window; however, what puzzles me is that the rub-rail itself is still - to my discerning eye - level and straight on the elevation plane, regardless that it clearly bulges outward some from the coach. My confusion arises out of the idea that if there is butt-sag (as I understand it to be: the ass end of the chassis has lowered) then the rub rail, too, should show evidence of lowering at the aft end of it. Which it does not appear to be. I should pull a string alone the entire pass/side rub rail to see for sure.
Also, I remember a thread on the Yahoo side a few years back on how to use a string pulled under the coach to check if the chassis has moved.
At this juncture, don't give a shit - I'm driving it regardless.
Terry
#846
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Elite Veteran
Location: Oceanside, CA | andy1canada - 2016-08-06 10:48 AM
At this juncture, don't give a shit - I'm driving it regardless.
That's exactly the way I feel about it ...I know I made it much stronger that it was...and now...it is what it is.. |
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Elite Veteran
Location: Oceanside, CA | New forward roof air conditioner cut out complete:
http://www.fmcowners.com/mbbs22/photos/show-album.asp?albumid=127&p...
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Elite Veteran
Location: Victoria, BC. Canada | Good job Lenny! I agree on the off-set thing, too. Let the wife bang her head :-)
Terry
#846 |
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Expert
Location: Cottage Grove, OR | Same question that Dan has, how did you get the 120 volt current line to that location? Where was your source and route? |
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Elite Veteran
Location: Oceanside, CA | I removed the upper cabinet here: http://www.fmcowners.com/mbbs22/photos/show-album.asp?albumid=127&p...
That gave me access to the wire that originally powered the converter(now removed), I cut it and routed it to the inside of the cabinet where I'm installing a receptacle and making the connection for the new leg that goes to the new Air Conditioner.
The cabinet removal was fairly easy...re-installation was a bear...it's damn tough to get those screw holes realigned.. |
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Elite Veteran
Location: Oceanside, CA | andy1canada - 2016-08-10 7:09 AM
Let the wife bang her head :-)
Terry
#846
Girlfriend is only 5'4" with thick shoes...she'd have to jump to get to it! |
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Elite Veteran
Location: Oceanside, CA | Roof Air Conditioners installed and tested:
http://www.fmcowners.com/mbbs22/photos/show-album.asp?albumid=127&p...
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Veteran
Location: Olympia, Washington | Len:
Do the modern AC units have a provision for fresh air exchange? |
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Elite Veteran
Location: Oceanside, CA | None that I know of do, they all work on "recirculation" and it's up to you to introduce new fresh air...of course with a 40yr old rig I'd defy to keep that from happening.. |
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Elite Veteran
Location: Oceanside, CA | As some further reference info I put a ammeter on the supply for my forward Coleman Mach 8 Cub 9200kbtu Air Conditioner, running on "High Cool" it only draws 10.7amps(which is 1amp less than it was advertised), it was mid 80's yesterday so that's a pretty good measure of what it needs power wise.
What this means for my overall supply system is that my 270amp alternator can fully sustain the power draw from my Inverter (even at 85% efficiency) at idle where it makes 190ish amps. The inverter doesn't even act like it has a load, it's a 4000watt unit so it's well oversized for the 1200watt load.
My house battery bank is 580ah so I have a good "cushion" for surge.
Edited by LCAC_Man 2016-08-16 10:11 AM
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Veteran
Location: Soquel, CA. | Can you see what it takes when the compressor kicks on, before the draw drops down to 10.7? |
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Elite Veteran
Location: Oceanside, CA | It just flashes on the meter (I saw 25 amps one time), I couldn't get a reliable reading. It doesn't hard load like a lot of the older/larger units do, it's really smooth. I'd expect it's 2.5 times the running amps though. |
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#1027 Duramax Conversion Project
