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Junior Member
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Discussion Starter #1
I own a 1981 Warrior Winnie 20' motor home that is on a Chevy chassis with a four barrel gas 190hp 350,400 tranny and a rear end gear ratio of 4.11's with 16.5 tires.It is 8,000 lbs wet.

What I would want to do as a swap is a 5.9 diesel.I know of a trans adapter company for the 5.9 to the 400.I was hoping to get some advise on this swap and hoping to find someone who has done it with a similar or same M/H.I would think to mock it up,a 1981 Chevy van would be the same.So even if it meant I had to buy a junk van like that,I would.I don't know if anyone makes conversion engine mounts.

I want in this swap to cover the engine department,do the swap right,and let the history of 5.9's mileage ability for trouble free driving happen well beyond my ownership of the M/H.I am 63 yrs old with experience in swaps.Just not with diesels and motor homes.

I'll look forward to your input.


Please and Thank You,

Gary
 

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Discussion Starter #2
Whoa........:)Kind of feel all alone here.LOL-is it something I said???.:confused:

I know what I am asking here is alittle out of left field,but with some swaps.What isn't??.

Please and Thank You.
 

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Super Moderator
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3,188 Posts
The mounts and trans adapter frrom the step van should be all the hard stuff. The finer details may also work, like the hoses & lines. It may just be the best thing to buy a whole bread van with the 4cyl Cummins. You can make up for most of the purchase price by selling the scrap body, and the 4cyl.
Not that I'm an expert.
 

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Junior Member
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Discussion Starter #4
The mounts and trans adapter frrom the step van should be all the hard stuff. The finer details may also work, like the hoses & lines. It may just be the best thing to buy a whole bread van with the 4cyl Cummins. You can make up for most of the purchase price by selling the scrap body, and the 4cyl.
Not that I'm an expert.
Your comment about a bread truck might be a good answer.I would have to see what those 4cylinder's power output is.

You reminded me yrs ago I had Chevy send me a spec sheet out of their archives.I dug that out and wouldn't you know it,I was wrong about the 350 hp ratings.Hard to believe,but the spec sheet saids it is a whopping [email protected] and 250lbs of torque at 2800rpm.Kind of makes me wonder why GM would do that.........It is ridiculous.

So I would need to swap in more than that and hopefully alot more.
 

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Discussion Starter #5 (Edited)
OK-I looked at the 4cylinder Cummings and doesn't seem to be much of a advantage over what I have now short of the newer construction very expnsive 4 cylinder diesels and those seem to have a very early and short hp/torque band.

The sweet yrs(and correct me if I am wrong)for a affordable 5.9 donor seem to be 1994 to 1998.5.I am surprised at the wt of these engines of what 1,100bls.But given the miles of service you get out of them there again maybe not.The stock 350 that is in there now is in the range of 500 to 550lbs.The rating for the motor home front end is at it's lightest version is 4,400lbs and has more heavy duty versions after that.So I am thinking I could cover the wt issues.

I need outside dimensions for a 5.9.The way I am thinking here is if I had to open up the dog house opening/build a bigger dog house and maybe redesign the dash and or use body mount spacers or a combination of all the above to make it fit.I am thinking like any swap,you sometimes have to take steps in virgin areas to make it work.Yepper-the greasy shoe horn.LOL

That would lead me to the rest of the power train.I have hear of Dodge's issues with trannies in that era of their trucks and I am seeing rebuilt kits that people are offering to cover that.As I said,I do know of a trans adapter company that offers a adapter to my current 400 tranny.But given the torque ratings make me wonder if over the long term the 400 even with a heavy duty mod would last.

This is in the early on of a learning curve,but one common thread I think I am seeing with these engines is a short rpm range for torque/hp.Of course off idle that is a good thing and maybe a bad thing for a step down passing gear.I would guess you guys figured out a solution to that I haven't learned yet.If you guys could please help me understand that,it would be helpful.


Again,Please and Thank You,

From Your Learned Newbie,

Gary

One thing I wanted to add in here.I am very sure I could build up the 350 that is in there to levels of torque and hp of the 5.9.I think that I would never be able to build the 350 to the service or fuel mileage I think I could get of a 5.9.That is my motive to all this.It's like paying it forward in the costs.
 

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Super Moderator
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No, I wasnt saying to use the 4cyl. I mean get the bread van with the 4 cyl so you have all the swap parts. Then, you can simply use those parts for the 5.9 swap, and sell off the 4cyl to re-coup some cash. The 3.9 & 5.9 are externally the same, besides being the size difference of 2 cyl. Meaning, what bolts up to the 4, will bolt to the 6. It would save a lot of hunting down of the small stuff.
 

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Junior Member
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Discussion Starter #7
No, I wasnt saying to use the 4cyl. I mean get the bread van with the 4 cyl so you have all the swap parts. Then, you can simply use those parts for the 5.9 swap, and sell off the 4cyl to re-coup some cash. The 3.9 & 5.9 are externally the same, besides being the size difference of 2 cyl. Meaning, what bolts up to the 4, will bolt to the 6. It would save a lot of hunting down of the small stuff.

Oh ok Dale.Thanks for the tip.Sorry about the confusion on my part.
 

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I can't help with the swap info, but you are probably going to want a transmission with overdrive... Unless you enjoy cruising at 50 MPH.
 

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Discussion Starter #9
Yes-I saw the limited power curve.I did ask if you guys found a way to widen that for more rpms.I agree that a o/d tranny is a must.The RV site I peep on is saying to find the 1994 to 1998.5 5.9 donor and use the tranny out of that.

Was those yrs trannies a weak link for Dodge??.If so,was there a fix??.
 

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Euro Sparky/ Wrencher
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1,065 Posts
I am not too well famuair with Dodge automatique transmisson however there were some issue going on and I know alot of Dodge diesel owner will know more details with this I think the 47RE series { if I recall it correct } have some issue with clutch band or pack one of the two.

Otherwise a well built 700R4 or simauir model will work with this set up as well so you may keep your orinial rear end.

With the overdrive enabled you should get top speed about 75 MPH or so if you leave the overdrive off the top speed will be about 50 to 55 MPH unless you have 3K or 3.5K govener spring kit then it will hold it longer.

otherwise you can add a vendor or other brand overdrive gearbox which it can be mounted right behind of the transmisson.

The 5.9 is taller and longer than 350 Chevy block so you may end up change the doghouse (unless you snag a inline 6 doghouse they are longer than V-8 series ) and if some reason you don't want to change the dog house then you can use the electrique raditors fans then you can able get the engine little closer to the raditor however there is other issue it will arise is the intercooler one way or other you will have to find a way to mount it

I dont have the excat size of the 5.9 Cummins but I am pretty sure it will be about 40 inches long and about 28 inch above the centreline of crankshaft { all it depending on what parts you use so it will afffect it some way }

Hope that clear up your question with this swap.

Merci.
Marc
 

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TDG Mafia Goon
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You will have to run overdrive. Those bread vans runs TH400s and they top out at 62. You could go with taller gears to make up some of the difference, though.

Not to step on toes Marc, but a 700R4 won't last long in there. Between the weight of the RV and torque of the Cummins it would be a nightmare. A built 47RH would be the most simple transmission swap. A gear vendors OD behind that TH400 would probably be the easiest answer.
 

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Euro Sparky/ Wrencher
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1,065 Posts
Yeah I know the stock 700R4 will not take the toqure of BT series engine it will be too much for it a well bleuprinted may hold up ok but Properly preped 47RE will handle it just fine.

The gearvendors OD IMO that is about the cheapest route you can use on this useage.

Merci.
Marc
 

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Junior Member
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Discussion Starter #13 (Edited)
The gear vendor's set-up is nice,Really nice that is.Costs of from the high two thousands to low three thousands is hard to take.I'm good as long as you guys think a mod to the Mopar tranny will handle the torque and the wt of 8,000lbs of the M/H.

A little of topic for the mods or Admins.I noticed the rating of 0 for the number of times I said thanks or thanked.If you read threw this thread,I think you will find that not accurate
 

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TDG Mafia Goon
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The gear vendor's set-up is nice,Really nice that is.Costs of from the high two thousands to low three thousands is hard to take.I'm good as long as you guys think a mod to the Mopar tranny will handle the torque and the wt of 8,000lbs of the M/H.

A little of topic for the mods or Admins.I noticed the rating of 0 for the number of times I said thanks or thanked.If you read threw this thread,I think you will find that not accurate
If you don't add any power to the Cummins you can survive for a while with a stock 47.

Use the little Thanks clicky at the lower right of the posts you want to thank.
 

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Discussion Starter #15 (Edited)
Don't know why I omitted the fact I expect this RV to tow a dual axle enclosed 12' trailer.Kind of embarrassing really.Still looking for a improvement of mpg.So I guess given that the 47 would have to have a mod done to it.Once those are done up,do they end up with a hash shift??.
 

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TDG Mafia Goon
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Don't know why I omitted the fact I expect this RV to tow a dual axle enclosed 12' trailer.Kind of embarrassing really.Still looking for a improvement of mpg.So I guess given that the 47 would have to have a mod done to it.Once those are done up,do they end up with a hash shift??.
Well, that changes things. Just kidding. The power adders are what will kill that trans. Plenty of people tow with stock Cummins and stock Dodge transmissions.
 

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Discussion Starter #17
Sounds like this is shaping like what I am about to tell you guys.I have a friend up in Montreal that told people he was going to put in a 97 Safari a Chevy Ramjet BBC.People told him he was out of his mind and it would never fit.So what he did was to take of donor van and cut right behind the rear of front door pillars.He used that for a jig to figure out all the problems which included welded to the sub frame 5 1/4" pipe body mount spacers.When he was done,it looked like the factory installed it.

I my case two donors.One for the engine and tranny and one 1981 bread truck cut the frame/body right behind the tranny mount.The body cut would be leaving the dash,windshield,floor board to use as a jig.Then transfer what was developed to the RV for the swap.
 

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TDG Mafia Goon
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That's a lot of work.
 

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Discussion Starter #19
Today's money to buy a decent diesel powered M/H would take your first born second mortgage.They are larger and some of the cheaper ones at $250,000,but this one is the size I want for what I want to use it for.Might actually be better too once i am done with it.

I figure to cut the noise down I would have to sound deaden it times 3.
 

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Senior Member
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The turbo 3.9 will move a loaded bread stepvan down the road nicely and it uses the same parts as the 5.9 ( other than the piston count ) and weights around 800#.

The 47RH (Dodge 94-95) with a new converter is probably the best choice for a transmission. If you want GM the model is the 4L60 unless you trip over a VERY RARE 4L80 and the 4L60 will need a diesel converter and governor installed.

My choice would be a 94-95 Dodge donor and be prepaired to make a new engine cover. It adds about 600# to the front axle and the front bumper may need moved foward to make roon for the radiator and intercooler. A 3K spring for the injector pump and when the tires need replaced go with taller rubber - 265 R 16 or 17 on the proper wheels. If the weight is a problem turn up a 3.9 at about 300# less.
 
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