Throughout the pages of Diesel World, you’ll see anything and everything, from innovative swaps, to 1,000-horsepower street trucks, to all-out competition vehicles. While the glamorous stuff can be fun, almost everyone still needs a reliable daily driver, a truck that can tow thousands of miles, doesn’t smoke and attract the smog police, and is just a good all-around vehicle. We know that people need this type of truck, because those are our most common letters; people wanting “just a little bit more oomph” out of their diesel, without sacrificing reliability or driving manners.
Enter Project Hot Rod RV Ram
While new trucks are pretty awesome, with their seat heaters, built-in exhaust brakes, and 350-400 horsepower, not everyone can afford their $50,000-plus price tag. Our goal would be to take an older truck and modernize it as far as creature comforts, horsepower and torque levels, and ride quality. Oh yeah, and it still would have to be able to do anything a new truck could do, like blast up grades with a camper and trailer. The truck we chose for this project was a 1997 Dodge Ram 2500 with a 5.9L 12-valve Cummins diesel.
Dodge 12-Valve Basics
The 1994-1998 Dodge Rams have perhaps the most potential of any older truck, and built correctly, can be very efficient as far as mileage goes, and also very low on smoke. They’re also the trucks you might see most commonly “rolling coal,” so whether our truck will have lots of smoke or almost zero smoke will inevitably come down to tuning.
The 5.9L Cummins engines in these Dodges (affectionately known as “12-valves”) have one of the best reputations for reliability out there. When maintained, we know of many of these engines that have lasted 300,000 to 500,000 miles without a need for a rebuild, and some that have went even further. One fellow we talked to had 640,000 miles on his, and had only done gaskets, rings and bearings when he rebuilt it. Last time we talked to him, he had more than 800,000 on it.
So the Cummins engines are tough, but what about power? Well, the good ole 12-valve does pretty well there too. In stock form, they were rated at 160-215 hp in Dodge trucks (depending on the year and model), but there was a catch. In Marine form, you could get a Cummins with up to 370 hp, which means that the engines were built for that type of power in mind. What’s more, doubling the factory output of the truck engine would be just a few simple changes away once we started modifying.
Inside Our Truck: A 1997 Dodge Ram 2500 Diesel
When looking for one of these older Dodges, the prices can fluctuate wildly, from about $5,000 to $15,000, depending on the condition of the vehicle. Although ours was a two-wheel drive (which meant it would be worth less), it only had 153,000 original miles, which is hard to find these days. The transmission had also supposedly been rebuilt, and some firm shifting led us to believe that the owner was probably telling the truth. The engine had also been modified with a different fuel plate, allowing for some more top-end fueling and power, and this too seemed to be true, as bone-stock 12-valves are painfully slow. Still, we won’t know anything until we get to a dyno and put some power to the ground.
So Where To Start?
Well, our first step will be to tackle reliability, since power won’t do you much good if your truck is broken in the driveway. These generation engines have a dowel-pin fix we’ll have to perform, and we also have a leak from our fuel return line (another common problem). We’ll also show you how to re-torque the factory head bolts, which is important as the years and mileage increase. After the basics, we’ll move on to increasing power, by adding timing, sliding the fuel plate, and a host of other simple modifications. Our goal is to keep up with the “Joneses,” with the Joneses being new trucks in this case.
Since all of them put down 350 hp to the wheels, that too will be our goal. We also plan to increase the rev limit of our truck to try to save the transmission, as often burning up a Dodge transmission is a result of too much low-end torque rather than too much horsepower. After power and reliability, we’ll move on to the interior, lighting, gauges and anything else we need to modernize our ride. Stay tuned in the next few months, where we’ll start fixing problems that are common to the 1994-1998 Dodges, which are of course issues that our truck already has. DW