Hi all, wanted to get some expert opinions from some folks on a diesel swap project. I have a 1970 Winnebago motorhome that sits on a Dodge D300 chassis. It currently has a weak and underpowered Dodge 318 under it that I want to swap for a solid diesel. Need the power and torque to tow a dinghy vehicle as well as to get up the mountains here in Colorado.

I was originally looking at the Dodge 12v cummins from '94 to early '98's, apparently they are a pretty clean drop in and pretty easy to modify for more power, but the transmission is the weak link in the whole setup, not to mention the cost or a high mileage cummins right now too. I was starting to look outside of the Dodge, specifically at maybe a Duramax and Allison transmission out of a wreck? I'm pretty handy with my own vehicle and my daily driver is an '02 Excursion with a 7.3, but I've never done an engine swap and have no idea what I'd be getting in to.

Thoughts? Suggestions on the above engines or other engines to consider? I know that with enough cash anything is possible but I'm looking for ease of install and durability. TIA!

 

For a swap like this, probably your best bet would be to get a running engine/transmission combo out of a school bus or the like. Stick with mechanical engines/transmissions unless you're pretty good with electronics. The 4BT is really hard to beat in terms of reliability, fuel economy, power, parts availability, etc. But other good engines that could do the same job are the International DT360 or that Ford Brazilian diesel (6.6 I think). Depending on how much room and weight capacity you have, there's also the larger DT466, Ford 7.8, and Cummins 8.3. All good engines.

Those International engines are every bit as good as the Cummins, and common enough that parts are no problem. The Fords are good engines though not as much power, but parts are hard to find.

Personally I'd stay away from most of the available V8 diesels. They're just not as good for a variety of reasons. The direct injection inline-6 engines particularly with the P7100 Bosch pump are really the way to go. The Cummins and International engines I've mentioned will hold up to anything you could reasonably do with them, even with quite a but of fuel turned to them. Not sure how well the Fords hold up to more fuel, but in stock form they work well. The tractor pull guys would probably know more about the Ford engines as they're also used in New Holland tractors.

 

Um... I meant 6BT.

Not that the 4BT is a bad engine. Just not big enough for most RV's.