Ranger Diesel Swap 3

Two weeks of fairly intensive research, figuring, measuring and imagining and now I'm better informed and still not completely sure that this engine conversion is going to work.

The original idea was to do a complete, factory-correct installation, what with having a donor truck that had all the parts necessary for such a job. Then I started thinking that this might be going too far to start out with and that a more moderate approach might be the better plan, with an eventual build-out with the original diesel wiring harness, engine control module, instruments, etc. The "new plan" was to use the Mitsubishi accessories (alternator with an attached vacuum pump, and the power steering pump), and just get the engine in the 4x4, get it running and tinker with the niceties as time permitted.

One important research discovery was a Mitsubishi Delica owner's forum, which contained a wealth of information about the 4D56 diesel engine and gave sources to purchase needed repair and maintenance parts. In trolling through a variety of topics, I discovered through looking at pictures of installed engines, that the JDM engine I bought in 2007 was definitely installed originally in a Mitsubishi L300 Delica. All of the part placements were correct, and the kicker was the duct pipe that leads from the air cleaner to the turbo inlet.

Some of the forum posts described how Delica owners dealt with niggling problems like the glow plug control circuit, fuel filters and such, and modification to the engine such as EGR (exhaust gas recirculation, an emission system) deletion. From this I formulated the idea that it would be completely possible to approach this initial installation as if it were an old 1980's VW IDI diesel engine. Being mechanically injected, the new diesel doesn't really need much more than fuel connections, an ignition wire, a starter signal, and the other common systems like radiator, exhaust, etc.

Well, careful measurement of the engine compartment and chassis of my 4x4 has proven that it's just not possible to install the alternator on the new engine in the mounting brackets provided for it without cutting the frame rails some in my 4x4. I'd be very reluctant to do this, and tried for days to find a solution, such as moving the oil filter to a remote location to free up some room for the alternator and vacuum pump. This morning, I made careful enough measurement to confirm that even this won't help enough.

In all, I came back to using the Ford alternator, vacuum pump and power steering pump, even in a ghetto installation to get the truck operational. Probably the hardest part of that is going to be the power steering pump, as there are a couple of mounting bolts that don't have a corresponding bolt boss in the new engine casting. The two that are there aren't drilled and tapped, so I have the nerve-wracking task of drilling and cutting threads in the cast iron block of the engine, with the hopes that I don't drill through anything important while doing so.

The last and final (?) thing I needed to do was to be absolutely sure that the the 4D56, which is much larger at the bottom than the gas engine I'm taking out, would actually clear the suspension under the truck. The Ranger 4x4 front suspension is much different that the two-wheel drive pickup I'm scavenging for parts. Ford uses (or used, I don't know if this is still a thing) "Twin I-Beam" suspension. On the 4x2 truck, all of this is neatly tucked inside the cross member under the engine. The 4x4, however, has a pivot bracket for the right-hand wheel beam that is mounted to the rear of the cross member, and looks like it will interfere with the crankcase pan of the diesel.

I spent some time today rolling around under both trucks with a machinist's rule, taking measurements. When I got out of bed this morning, I knew this would be a make-or-break matter for the swap. I never was able to confirm to my satisfaction that the 4x4 Ranger (or the Bronco II) were ever offered from the factory with diesel power. Since discovering the differences in suspension, the viability of this engine swap was always a big "Maybe".

My measurements came down to the one area where the pivot bracket is attached to the cross member. This just barely clears the cast aluminum pan on the gas engine. What I found on the installed diesel in the 4x2 truck was that there is a nice, flat "dent" in the pan at this area. I had thought upon seeing it some time back that it was just road damage from hitting a rock or limb or something, but now I think that the crankcase pan was actually designed and stamped at the factory to clear the suspension on a 4x4.

I've now updated my expectation of success in the project from "Maybe" to "Maybe-Probably". There's still a lot of work to do.

A couple of images of an engine that I didn't buy. A brand-new, latest version of the 4D56, complete long block engine only lacking the injection pump and accessories from my old engine. At the time, I just didn't know enough about what this swap would take or if the 4D56 was going to be a direct replacement for the 4D55 that I have in my donor truck. At $2500 each, these were a steal. I'd put that out fast for one of these today