Motorhome tow rig and diesel swaps...

[LCexplorer]

I just picked up a nice 27' class C motorhome. It's a 1984 Ford E350 chassis with a carbed 460, C6 and a nice Dana 70 rear. I plan to tow my Landcruiser with car trailer or 22' boat with it. I already have a weight distributing hitch, would it be a good idea to get rear airbags as well or is the weight distributing hitch enough?

The primary reason I picked up the motorhome is to make trips out of town for work easier and more comfortable. Trust me it's no fun with 4 of us in a '97 Dodge club cab for 18 hours and then spend 12 hours on the end of a jackhammer. I do a lot of travelling for work and it's usually year around, so the motorhome is going to see a few miles (probably 20K a year on average). The thought of converting to diesel crossed my mind, what do you guys think? There would be a big differnece between the 7 mpg I see now and 12-13 mpg I probably would see with diesel. Do you think it's worth the bother? I plan to go with a idi 7.3L because they are relatively cheap and plentiful with an E4OD auto tranny. That and they would fit in the ford chassis using factory motor mounts. The wiring doesn't scare me that much. But I am pretty sure I am not seeing the big picture with the diesel swap and missing a few details. So far I have looked into a bigger rad , the springs for the front suspension and probably a turbo kit. I am not sure how the tranny linkage is going to work out, does anybody know if the shifting lever is in the same place on a C6 and an E4od? The rear end gearing would probably suit a diesel better as the current 460 runs pretty good into 75 mph but is a little slow on the pickup. Is there anything else that I am not taking into account with a motorhome/diesel swap? Before anybody mentions powerstroke, I am getting a good deal on the 7.3 idi and it's a lot less wiring. Any comments would be greatly appreciated.

[Oxjockey]

Have you thought about emissions? While you may not currently be tested, your vehicle will break like every law out there in regards to it.

I'd also consider the weight. I'm assuming the front end can handle the extra weight of the motor?

[Joe_W]

check with a guy named SSSrodeo on this board (think thats his screen name). He has a Class A motorhome that he took his Ford BB out and swapped in an Isuzu medium duty diesel in

[Rudezuk]

I wouldnt go through the trouble of and IDI motor.....Not enough power to pull a rig behind that motorhome...

[DSI]

Originally posted by RudeZuk
I wouldnt go through the trouble of and IDI motor.....Not enough power to pull a rig behind that motorhome...

really?

how so? an aftermarket turbo, some pump mod's and a nice exhaust and you can make very respectable power out of the IDI's i've seen dyno run's of 255RW HP on an IDI motor, that's better than a bone stock 7.3 PSD

[Rudezuk]

Well from my understanding from other IDI owners, even with the turbo added and exhaust a stock truck weighing in about 6k lbs towing about 5k lbs struggles quite a bit in the hills..

It does alright towing on flat ground but the hills is where it dies.

It is hard to believe that an IDI motor will put out 255 to the wheels when they are only 180hp at the crank to begin with N/A.

This info is from the banks site....all Crank HP

Horsepower, best gain 176 hp (3000 rpm) 260 hp (3000 rpm) +84 horsepower 48% more (3000 rpm)
Torque, best gain 360 lb-ft (1400 rpm) 503 lb-ft (1500 rpm) +143 lb-ft torque 40% more (1500 rpm)

I just think for the trouble of doing the swap an early cummins motor might be a better choice.

[DSI]

banks

yea, they forgot about the "smoke screw" on the pump

[Rudezuk]

Originally posted by DSI
banks

yea, they forgot about the "smoke screw" on the pump

But if you try to pump too much into an IDI motor it will bring its life way way down! The head bolts will not hold up to alot of boost or a turbo with propane. He said he wants to drive this 20k miles a year, im thinking he wants reliable power too

[DSI]

Originally posted by RudeZuk


But if you try to pump too much into an IDI motor it will bring its life way way down! The head bolts will not hold up to alot of boost or a turbo with propane. He said he wants to drive this 20k miles a year, im thinking he wants reliable power too

reliability isn't even an issue, if he's going through the process to swap it in, i'm sure he wouldn't object to doing the few small reliability mod's that are avail, head bolt's being one...

the local diesel shop guy's kid has a 6.9 IDI with turbo, on 35's with 3.55 gears and a 4sp that will drag they're 30ft gooseneck, stacked 12ft high with hay over snoqualmie pass at the speed limit in 4th gear and not even get hot... motor's got if i remember right either over 80 or 90k since it was tuned up... 200+ on the clock... never been opened up, and teh kid rod's the crap out of it...

so your theory's flawed shane... the mod's are there, and they are not expensive, some just slightly time consuming...

[Rudezuk]

HMMMM new stronger head bolts for a 6.9?
Let me know where to get these, none of the diesel shops around here have heard of a stronger head bolt.

They are a 7/16ths grade 8 head bolt already. If there are some out there I will gladly swap them into my rig so I can put some more boost to it!

[MattS]

Originally posted by LCexplorer
So far I have looked into a bigger rad , the springs for the front suspension and probably a turbo kit.

If your going to turbo it, add an intercooler on the list as well.


I 2nd the cummins swap. More details as to fit, but easier to mod and may even be cheaper in the long run.

[smurfsdad]

Someone on here has already done a swap, talk to em.
http://www.pirate4x4.com/forum/showt...hreadid=170493

[SSSRodeo]

LCexplorer

Hey after reading your ideas I gotta reply. I am wrapping up the little details on my conversion. For starters I swapped out a 460 Ford and C-6 to a 5.9L Cummins and Allison AT542 Tranny into a Class "A" Motorhome. Front engine model!

There was so little room to work with in the Class "A", I can't imagine trying to do a diesel swap into a Class "C". What a nightmare. Have you thought about finding a Diesel powered 1 ton van and swapping the Motorhome parts onto it? I ran across several of them during my parts search that had been rolled.
My project was like building a 1500 lb ship in a bottle.
Here is a link to my "TDR"write up. IF you'll scroll down you'll see the link to my photos.

A straight 6 was difficult enough, I can't imagine trying to stuff a Turbo Diesel V-8 in a van chassis. Plus that way you'll know the suspension will handle the engine weight.

There is another write up I did in the early stages on the TDR board. It's a good place to hang out for conversion ideas, but, be forwarned they are more Cummins oriented. There are a few Ford Power Stroke guys there ,but not many. Try the DIeselStop.com for Power Stroke info.

Anyway, Your reasoning sounds a lot like mine in the beginning.

I expect to go from 5 mpg to 12 to 14 mpg with this conversion. Plus, I'll have a nice size rig that won't be closing in on me after a week on the road.

Sorry I don't have any specific Ford TD info to lay on you. I do know that the Power Stroke Trucks I've driven over the last 8 years have left me dissapointed me. Had a lot of trouble out of them. But, since they were Company Trucks, I drove the piss out of them everyday. So it could have just been me.


Good Luck with it and if I can help point you in the right direction let me know.


SSSRodeo

[LCexplorer]

Thanks for all the responses so far.

SSSRodeo, I have been watching your conversion progress for the last 6 months on the TDR board with great interest. Only one question about your post, I didn't quite understand:

Originally posted by SSSRodeo
LCexplorer

Have you thought about finding a Diesel powered 1 ton van and swapping the Motorhome parts onto it?

I wasn't sure if you mean to buy a diesel one ton van and convert the stuff onto my motorhome chassis or vice versa? But thanks for all the great info.

I did a little research before seriously considering this conversion. I found that the long wheelbase E 350 cab chassis (used in class C motorhomes) were the same frame and suspension for both diesel and 460 gas for the '84 model. But comtemplating ford engineering, I am pretty sure that the front springs were a little soft from the factory with the diesels. I'll probably putting airbags front and rear as well. The other nice thing is that Ford still stocks the 6.9L/7.3L diesel motor mounts so it will not be a huge project to build motor mounts. The wiring will be realtively simple (well for a ford) for the 7.3L idi diesel (the idi is about a third of the wiring then of a powerstroke). Talking to both Banks and ATS they said that there kits for the 7.3L idi would also fit van/class C applications as well with a little modification. I am hoping to keep the vehicle close to stock so that I can walk up to a ford parts counter and get parts if need be in some remote little sh*thole town that I usually work in.

I gave a lot of thought to the cummins 5.9L conversion as well as I love this engine as I have one in my truck. The 5.9L cummins in my truck has lasted through hell and is still ticking at 240K miles. The problem with swapping into my motorhome is that I can't fit the engine lengthwise into the engine compartment. I would have to have carve up the floor and dog house to fit it. If the engine were only 2 inches shorter, I would be sliding one of these into the engine compartment.

As for performance, if the turbo 7.3L idi can match the current 460 in my motorhome now, I would be very happy. If it can move my motorhome and landcruiser/car trailer load at to 60 mph on flat land, I would be happy. Doing 40-45 mph in the hills while towing doesn't bother me as that's what my 460 does now. If I need to tow the load at 75 mph, I'll take my truck. My main concern is better fuel economy, so towing is not a necessity just a nicety that's if I ever make it to the Moab. Mainly towing would be a once a year affair when on vacation.

Thanks again for all your guys opinions and suggestions, please keep them coming.

[SSSRodeo]

quote:
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Originally posted by SSSRodeo
LCexplorer

Have you thought about finding a Diesel powered 1 ton van and swapping the Motorhome parts onto it?
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Like I said, I'm not real literate when it comes to Fords, but I do know that the big Ford passenger Vans can be had with diesel motors. Our Church Van is an 18 passenger diesel van. Since I believe most Class "C" Ford Motorhomes come in the gas version, then maybe you could find a rolled or wrecked diesel version van and have all the parts you'd need to convert the Class"C" to diesel. It would just be a matter of swapping in all the diesel part over. Suspensions, transmissions and stuff like that. Might even be able to mix the rear axle parts and not even have to regear. Since most Motorhome axles are duallys.
On my conversion the biggest headache was trying to find all the little pieces for the conversion. I often spent days fabricating mounts and other parts. Then often I'd have to redo them to make them work with the next piece of the puzzle.

I'd have to think real hard before I started another one. Course, now I know more about what works and what doesn't. So it could go easier the second time around. I didn't know diddly about diesels before this project. But, I had done a lot of wierd and unusual swaps before, so I just raised the learning curve.

This could be a really interesting swap. Keep us informed.

I'll be driving mine tomorrow to determine the rpm to axle ratio.
Had a little motorcycle wreck this week which put me behind again. Nothing broken but the bike, but bruised all over. I'm gettting too old for those high speed get offs.

SSSRodeo