Build your own diesel RV

Discussion in 'Shiny Things' started by Joz, Apr 27, 2011.

  1. Joz

    Joz What could go wrong?

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    The RV is running great. It's getting the brake system totally redone right now. I probably have about 25k miles on it since the conversion and still loving it.
    Funny to see this thread revived though. Thought it was long forgotten by now.
  2. terry.mc

    terry.mc Stop ruining my vacation

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    Your work on this project is what makes me giddy when I see E350 Gas van on sale cheap. I know in the back of my head that it's possible to shove a 6BT in them :)
  3. dieselpete

    dieselpete Been here awhile

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    Awesome job! One thing to watch, the pin holes in #4 cylinder was most likely caused by cavitation. This occurs with poor quality, or non diesel coolant. This is more common on wet liner engines. As the compression engines create "shock waves" in the coolant every power stroke, causing the cavitation. Coolant maintenance is critical on diesels, and Cummins offers coolant filters, and head assemblies for the 5.9.
  4. Ridgway

    Ridgway Been here awhile

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    Awesome project! I just bought a 1989 Ford Born Free 24 footer, and I'm going to do the same swap (thanks to you Joz!)

    Did you have to replace the front springs or do an alignment? Do you know what the weight difference is?

    I want to use the same transmission as you because you proved it works. How difficult was it to find the stock clutch pedal assembly? Did you ever think about using a billit clutch pedal/master for a race car? I wonder if that would be better or easier to install?

    I was going to use aftermarket gauges but yours looks super clean. Was it difficult to do or would it be easier to go aftermarket?

    I might have missed it, but what mpg are you getting after all the motor issues were fixed?

    Sorry about all the questions but there aren't many people who have does this swap, and with such success!
  5. TARider

    TARider Been here awhile

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    Quoted from Turbo Diesel Registry:

    Q1: I’ve often heard the term “cavitation erosion” in the same sentence as diesel engine. What is cavitation erosion?

    A1 With a term like “cavitation erosion,” you might think those affected would be found in the waiting room at your dentist’s office. Not so. Cavitation erosion or liner pitting, if left unchecked, is a real issue with some diesel engines. Okay, I guess there is a parallel to your dental hygiene. A cavity is a cavity, and both types can drain money from your wallet.

    To further clarify the issue, you may have noted that the cavitation erosion is an issue with some diesel engines. Which ones? All diesel engines with wet sleeves are subject to cavitation erosion or liner pitting if the cooling system is not properly maintained. The wet sleeve design means the cylinder liner can be removed and replaced in the block. Although the cylinder liners are pressed into the block, wet cylinder liner design does not have the same structural rigidity as a cast block design.Under-concentration of coolant treatment additives will result in liner pitting and engine failure.

    The Cummins B5.9 and 6.7 liter engines are a cast block design and do not have wet or removable sleeves.

    To add further explanation to the liner pitting phenomenon, I’ll quote from a Cummins Inc. Cooling System brochure. “Liner pitting is caused by vapor bubbles formed when the piston strikes the liner during engine operation. The energy generated during the combustion process and the side-to-side motion of the piston causes the liner to vibrate at a very high frequency. The liner moves away from the coolant fast enough to form vapor bubbles.

    “The vapor bubbles collapse against the liner surface as the liner moves back into the coolant. The implosion of the vapor bubble against the liner surface produces a very high velocity jet of water. This water jet removes material from the liner surface. The jet of water acts on the liner surface with a pressure exceeding 15,000 psi. This process repeats again and again, resulting in liner pitting.”

    Q2: Is cavitation erosion or liner pitting a concern on my Turbo Diesel?

    A2: No. Again, the Cummins B5.9 and 6.7 liter engines are a cast block design and liner pitting is not a concern.
  6. dieselpete

    dieselpete Been here awhile

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    So your saying all non-wet liner blocks are not liquid cooled?

    This also occurs on cast blocks. If the coolant system is not maintained will erode the metal between the coolant, and cylinder. Hey what would I know, I'm not an Engineer, just one of the poor bastards that fixes their designs years after the drawing board!
  7. Joz

    Joz What could go wrong?

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    Awesome idea to take a quality body like the BornFree and put an adequate power plant in it!
    I did nothing to the front suspension for this conversion. I figured a couple hundred extra pounds wasn't enough to worry about. It handles just the same as it did before the conversion. I didn't realign it either.
    I'd suggest using what ever transmission best suits your needs. Getting the right gear ratios is key. The G56 worked because of the differential gearing and diameter of the OEM tires. You may find different results if your gears or tire size are different. RESEARCH.
    I used the factory brake/clutch assembly as I really wanted a simple original appearing swap in the cockpit. I considered race car style pedals but was able to find what I needed rather easily.
    Again, I wanted something that looked stock to the casual observer. The biggest pain was the speedometer since the G56 doesn't have any speedo drive - mechanical or electronic. I used an aftermarket vehicle speed sensor from Dakota Digital to drive an Abbot-X VSS to mechanical drive unit. That took some fiddling with to get the programming right but I haven't had a single issue with it since. Not cheap at $300 though.
    MPG has been about 13's and up. The last 3 tanks I put through it were 16.5. I finally started consistently putting in properly measured amounts of fuel additive. That seems to have done wonders for fuel consumption.

    Good luck with your conversion. I'm sure it will be worlds better than the thirsty 460.
  8. Ardyjay

    Ardyjay Been here awhile

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    Great article! Just seen it tonight for the first time.
    Got a few shocked gasps out of me too!

    I did a somewhat similar thing with our Fire Depts aluminum bodied Kurbmaster gas pig POS rescue truck back in '95.

    I kind of cheated though- We ordered a brand new 1 ton, 6.5L Chev chassis for $22K (probably about $15K USD at the time) from GM and switched the body over. They come complete right down to the steering wheel, instrument package and running lights. We saved a fortune over buying a new rescue truck, and its still good as new today.

    On a slight variation- I once saw a camper a guy made from the front section of a DC3 fuselage that was grafted onto a Lincoln Continental chassis. About 30 ft long IIRC. Super lightweight and strong as hell.

    You drove it from the pilots seat, and he claimed 120 mph on the highway in Nevada, I think. I always though making aircraft into campers would be pretty cool!
  9. Ridgway

    Ridgway Been here awhile

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    Joz, can you hear your passenger talk while cruising down the road? This is pretty important to us (girlfriend and I), and if so, what was the proper way to insulate everything?

    Is heat an issue inside the cab?

    I'm so stoked to get this started...and so nervous at the same time.
  10. Joz

    Joz What could go wrong?

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    Ridgeway - check your PM.
    As for noise, yes that was a major concern for me too. At first it was difficult to have a 'normal' conversation but the engine side of the doghouse was insulated heavily as well as the passenger compartment side. I used MLV (Mass Loaded Vinyl). That's what did the trick. I can have a normal conversation now. Of course, you still know that there's a diesel engine in there, but the road and wind noise are equally present.
    I was concerned about heat in the cab, particularly from the turbo. Actually, it has never been an issue, even before I insulated the dog house.
  11. rebar

    rebar Been here awhile

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    Joz.. Did you by chance measure the width of the engine compartment?
    I'm having a heck of a time finding the big block 4x4 van and really need and want to know if the doghouse for a straight 6 was the same part # as the doghouse for the 460 or what ever big block was available for that same year?

    If I knew a straight six equipped E250/350 doghouse was the same as the big block doghouse, it would open up more eligible vans for sale in my area.

    I figured easy enough.. find genuine part number and compare.. But I cant find genuine ford part #'s. Must be a secret so you cant search for better prices.
  12. rebar

    rebar Been here awhile

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    I was so intrigued by this build I found a 5 speed 1st gen cummins van and then proceeded to blow it up hauling my toyhauler to colorado. Massive blowby, rings gone.

    If anyone wants to see my tear down and then later the rebuild.. Here it is and updated as work continues. I wanted to convert it to 4x4, but, yeah.
  13. Ridgway

    Ridgway Been here awhile

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    Just re-read this thread for the 10th time! Finally got my Born Free running the other day! I went with the 47RH trans with a lock up converter.

    I have some bugs to work out. It's not pulling as hard as it should. I might have messed up by leaving the stock Ford in-tank fuel pump in...