Originally Posted by Chance
When people buy Cummins diesel engines for industrial or marine applications, do they not come complete with computer and all wiring harnesses required to make them operational as a stand-alone power plant? And also when used for Motorhomes, school buses, or medium-duty trucks, would it be that different than industrial or marine except for the throttle and transmission interface?
I'm only asking because I'm not sure just how difficult it would really have to be to supply an engine to be mated to an Allison or Ford transmission when there are not a lot of other body controls involved. I expect (more like a guess) that controls for a Class A with Ford V10 are a lot simpler than that for a Ford Econoline van.
The engines do come with ECMs and harnesses (the engine side harness anyway, C1 connector on the 6.7L ECM for example) and they're set up for the application that they'll be going in. They're basically drop-in ready (when you plug in the "OEM" side of the harness...that is the vehicle specific body harness, C2 on the ECM). The calibrations for the ECM are developed by Cummins and based on several factors related to the vehicle specs and the usage model. There are a number of configurations and power levels for each engine and they're all downloadable from Cummins and flash-able to the ECM if you have the right software, a user account and pass-through device. The software is somewhat reconfigurable to set up things like security, cruise control, throttle controls, etc... One of the problems from what I am able to gather is, the most configurable version of the software is available only to Cummins dealers and certified service shops. Not unlike Chrysler's TechConnect...or whatever the dealer-only online service is called. You may be able to convince a shop to flash an ECM with a Cummins calibration (if you find one that might work for your application) but you won't be able to do any upgrades like adding on aftermarket stuff (as-in tuners commonly available for Ram trucks). Another problem with this is that the calibrations are really designed for medium duty applications so the drivability might not be the greatest in a light duty truck. Maybe not so bad for a motorhome but a pick up, van or jeep might lack a little finesse to start with before you do some tuning...if it is even possible to do much tuning without a direct link to a Cummins service expert. I haven't found much info on this yet. I am researching the viability of this approach because of the big headache associated with the security in the Ram truck ECMs. ****EDIT**** Just after I posted this I found some info about tuning the ECMs with Cummins software. I was told it wasn't possible without a visit to a Cummins shop but I've now found evidence that it can be done in a DIY kinda way...provided one knows what they're doing of course. The internet is awesome!
For the Ford van, the module communications network is way simpler than the F-series and Ram truck. And I mean WAY simpler. Probably about as simple as a CAN module network can be in a newer vehicle, I would imagine even simpler than a newer motorhome. But even though the network of modules is simple as heck, it doesn't mean that integration of two or more different systems is trivial. You'll need at least one custom module to be a "translator" of one bus to the other.
Now, could Cummins come up with a generic solution that might work for many applications and make it easy for guys to re-power with a new engine/trans? Absolutely. Will it happen? Unfortunately, Probably not. I think the biggest reason is that Cummins's business model is probably more geared toward supplying OEMs with truck loads of engines vs. selling a "crate engine" here and there for a custom rig. I can't imagine them going through the trouble to make a kit for something that might only sell a few hundred units a year. We're talking about a very small amount of revenue compared to their other businesses.
There are a couple challenges with some of the stuff I've talked about above but doing what you're talking about isn't impossible. I'm not going to hesitate to "productize" something during the process of my conversion if I see that there is an opportunity. I have only seen a couple things that might make a decent return though.