Dodge 440 to 5.9 Cummins Diesel conversion

[Froggy1936]

FANTASTIC ! Breaking the 10 MPG barrier is a big step Looks like with all the right conditions you may make 15 MPG Congratulations  Frank

[Wantawinnie]

Thanks guys! Pretty pleased with the performance and economy so far. I forgot to mention there were numerous waves and thumbs up along the way. That was an added bonus which probably had nothing to do with the diesel but just the Winnie itself.  

One of the mechanics texted me to make sure it made the trip and then the carpet guy checked to make sure I got home as well. Glad it didn't break down or that would have been embarrasing.

I'll have to get a video of it going down the road to give everyone an idea what it acts and sounds like on the highway someday. The flooring and dynomat sure helped quiet it down inside. The exhaust still has a bellar but it is not too bad.

[LJ-TJ]

Good stuff. Now we really have something to ponder. I've thought of it often and I no the guys here have talked about it a lot  but we've never had a yard stick to measure by.  By the way thanks for the GREAT thread with pictures and explanations. Fantastic. Thanks again.

[Wantawinnie]

Put about 240 more miles on the diesel. Made a few grocery runs, a Menards run, and some work related driving. Few miles were flat road, most were hilly country roads. I spent about twenty miles on the interstate but the wind was bad and it was hilly. Another 30 miles of straight headwinds with almost full throttle to maintain speed. Basically  tough conditions for at least half the miles driven. Average of 10.6mpg on this tank. Very little double overdrive, a lot of gear vendor overdrive.

Once in double overdrive I did get the attention of a State Trooper while cresting a hill and got the flashing headlights and slow down motion from him,  so yeah,  I am not babying it at all .   W%

[ClydesdaleKevin]

AWESOME!!!  When it comes the time to rebuild or replace our engine, I'm definitely going to consider this, and reference this build thread heavily!

Kev

[DonD]

I've got one in mine...........



The new bus that is!!

[Dr. Righteous]

Man Oh Man.


I purchased my classic motor home expressly for a Cummins conversion.  Don't know when I will get around to it because life tends to shake up your plans.  Here is my '78 Avco.  440, on the M600 chassis.  The rear is a Rockwell with 4.88 gears.  Going to be more of a challenge hitting the 1800 ideal cruise RPM at 60mph. 

[TripleJ]

I've got one in mine...........


The new bus that is!!

Before I read the text, I was gonna say "damn nice work, looks factory" D:oH! D:oH!



Wantawinnie, did I miss it or have you put up some rpm/speed numbers yet? 

[DonD]

Mr. R, FWIW my bus has 3.54 gears, 19.5 wheels and 1:1 top gear. I'll have to get the rpm/mph numbers. fairly close tho'.

[eXodus]

Very good built very good documentation.
I'm curious would a newer Cummins also fit ? The newer 5.9 or the 6.7 ?


Ever thought about running it with vegetable oil ? I ran a couple of old cars with WVO and this old engines did great.


Kevin our 454s would be probably easier replaced with newer Duramax 6.6L and an Allison Gearbox. About some size and weight.

[Wantawinnie]

Before I read the text, I was gonna say "damn nice work, looks factory" D:oH! D:oH!



Wantawinnie, did I miss it or have you put up some rpm/speed numbers yet? 

Hooking up a diesel tach is a little involved so I don't have one yet. Probably going with the digital Tiny Tach brand for cost and ease of installation.

I will say there are enough gears to get the rpm comfortable at whatever speed needed. My final drive ratio in double overdrive is nearly identical to having a 3.55 gear axle with factory overdrive. Gear vendor OD is effectively the same as 3.55 final ratio, factory OD is a 3.15 ratio, and double OD is a 2.45 rear end ratio. The Cummins likes them all. 

[Froggy1936]

Hey Wanna back when VW came out with there diesel The dealers were sold a Tach that had a magnetic pickup that you could just place anywhere on the engine and get a RPM reading This tool would be available at any VW dealers parts dept (may have to get part no from service dept ) and cost is unknown but worth a look   Frank

[Wantawinnie]

I wanted to try a Dakota Digital box to run the factory tach. I hate to spend that much to run a 40 year old tach that is obsolete with no parts available. I've studied that option a little and think the Tiny Tach with just a wire wrapped around the #1 injector line and 12V power will work just as well. It also keeps track of engine run time.

[Wantawinnie]

Very good built very good documentation.
I'm curious would a newer Cummins also fit ? The newer 5.9 or the 6.7 ?

Ever thought about running it with vegetable oil ? I ran a couple of old cars with WVO and this old engines did great.

Kevin our 454s would be probably easier replaced with newer Duramax 6.6L and an Allison Gearbox. About some size and weight.

The newer ones would probably fit about the same but the 6.7's are loaded with emissions and computer controls. The common rail 5.9 doesn't have as many problems but the wiring and computer controls are still needed.

Haven't really looked into alternative fuel at this point.

[eXodus]

Thanks for clarifying. I'm into Diesel and know the Aftermarket makes Standalone computers for the 6.7 so you can strip off all the emission stuff. 


The Diesel scene puts the Cummins 5.9 virtually everywhere, and Computer controls are not really bad. You've got a couple of sensors around the engine to control the Common Rail and the Transmission.


There are Sensors for the Alternator available to create a Tacho Signal.

[Wantawinnie]

I am not familiar with any stand alone computers and harnesses for the Cummins. If they are out there that would definitely make it easier. I have used several programmers for the 5.9 common rails on my pickups in the past and have looked at some of the emission delete and programmers for the 6.7. Those still required the factory ECM, sensors, and wiring.

I really wouldn't consider a 6.7 for a swap now as the EPA has cracked down hard on the emissions delete companies and those programmers have gotten very expensive and illegal for street use. I can't imagine any way that swap would be cost effective. Some of those programmers cost more than I paid for the whole 5.9 cummins parts truck.

Now, the earlier 5.9 common rail (2003-2007) with the block mounted computer would probably be the easiest and make for a nice swap. I would want a non computer controlled transmission like a 47RH but that is just me. One nice thing is that they are much quieter engines than the earlier versions and don't have the emissions issues of the later 6.7. There are several variations from 2003-2007 and they all make more power than the one I swapped in. In my case I don't know if the original gas engine cooling system would be up to the challenge. The intercooler would likely need to be resized then also. I went with the early 12 valve Cummins for rock solid reliability, rather simple design, and cost. I could turn up the power on mine easily but right now I am happy with the performance.

My early alternator doesn't have a "W" terminal so the running the tach off that doesn't work from what I have read.

[kattkisson]

Ran a Tiny-tach on Lesharo Diesel.  Was very pleased with unit but if you have failing eyesight the display in not very large. Never let me down.  Since the Lesharo had a pump system the sensor clamped around the 6mm injector tubing.

[eXodus]

there is a sensor available which you strap on the alternator surface. dont know the name sorry.

i would also go for the later 5.9 cummins not only because of the electric. the block is more available and more and cheaper aftermarket parts. also it has a better fuel economy then the 6.7. but this is no brainer, the bigger bore and epa has its toll.

sure the 6.7 would have more endpower, but how needs this ?

[uglydukwling]

Chrysler dealers sold an add-on tach for this engine. The '92 and up came pre-wired for a tach, and the dealer sold me this version first. I had no place to plug it in on my '91 1/2, so he got me the correct one. It came with a piece of magnetic tape to put on the crankshaft pulley. If it's not available through dealers any more, look for a '91 or older in the junk yard. For a later engine, it would depend on how much of the original wiring you kept. You may have a place to simply plug in a tach.

The Perkins in my Winnebago has a tach driven off the alternator. There's no terminal on the alternator for a tach wire. The wire goes into the alternator through a vent slot and is connected somewhere inside. The conversion had already been done when I got the Winnebago and I never saw the tach installation instructions, so I don't know whether the instructions tell you how to do it, or whether you have to know what you're doing, but it can be done. Unfortunately, I don't know what brand my tach is. There's no name on the face, and the body has been painted. It only reads to 4000 rpm, so presumably it was made for truck or heavy equipment use, not the hot-rod trade. A truck equipment dealer might be a place to look.

[DonD]

Mr. R, FWIW my bus has 3.54 gears, 19.5 wheels and 1:1 top gear. I'll have to get the rpm/mph numbers. fairly close tho'.

55mph indicated=2000 rpm on flat ground.

[Wantawinnie]

Gear vendors makes a motorhome specific unit with a parking brake. The original won't work as it is part of the 727 trans. I don't have a parking brake as the gear vendor was bought used. The original wasn't working anyway. I was considering a line lock on the front discs or possibly converting to some newer rear disc brake axle that has a parking brake at some point. Not high on the to do list right now so I just use wheel chocks.

[kansascat]

Wantawinnie, just wondering if there was anymileage updates and performance conclusions out on the road?

[tmsnyder]

What's a reasonable price for a donor truck these days if someone wanted a 12 valve 6bt?

[srosa707]

@Wantawinnie I know its a tall order, but any chance you could update this thread with the photos lost on PhotoBucket?  I am very interested in this swap and your detailed description would be a great help.  Also, its been a while since you completed this swap.  How do you like it?  Noise?  Mileage?  Any other important feedback?

[Wantawinnie]

Hello again! Still here!!

I started to try and update the post from the Photobucket fiasco using this site for hosting so it will be permanent. The 4 picture limit per post is a problem at this point as some of my posts had more. I started editing the posts so it would still make sense with the written text but it will take some time.

As far as the swap, I love it. In regard to noise it is not a problem really. The "main" noise at this point is the side exit exhaust when windows are open on that side while driving. It is most noticeable when going along highways that have concrete side barriers or over bridges. I may take a look at running the exhaust all the way back or going to a quieter OEM type muffler at some point. You do know it is a diesel under the engine cover but nothing bothersome to me.

The last mileage reports were in the 10-12mpg range in rather difficult driving conditions. Since those reports I pulled the diesel injectors and had them tested. Two had pop pressures way off and one had a constant dribble. Most likely original injectors to the engine. I replaced them with a set of OEM rebuilds and it cleaned up smoke on start up and idle is smoother. I am hopeful that a mileage bump will also be realized.

As I write this the Winnebago just traveled 150 miles pulling a 12' trailer and golf cart to a campground along the Mississippi river. I absolutely love the gear vendor overdrive and A518 combination as it gives tons of gearing options on the highway, rural roads, and in town.

Tranny temps pulling the trailer maxed out in the 180-190 range and engine temps were 160-180. EGT's maxed out at 1150 with foot to the floor on longer grades which is what I wanted. I don't want to have to worry about it getting too hot while pulling grades. Keep in mind this is a big rig as far as Eyebrow Winnebagos are concerned. My weight is probably close to 13K pounds or more just with the coach. A lighter rig would perform even better.