Last time in Dirt and Haul (Feb. ’15), we introduced you to our unicorn of a truck: a ’98 Dodge 12-valve diesel Quad Cab 2500 4x4 with a manual transmission and only 145,000 miles. We also covered how we took the truck to Diesel Power Products in Spokane Valley, Washington, where the boys in orange installed an awesome suspension system with parts from Carli, Synergy Manufacturing, Fox, Daystar, and Pac Brake, just to name a few. So far we’ve been racking up the miles using our Dodge as intended both on-road and off-road, and the truck is awesome, but the truth is we didn’t tell you the whole story. In hopes of getting as much detail about the suspension in Part 1 of Dirt and Haul, we skipped over all the engine performance upgrades and maintenance Diesel Power Products did with our unique old ranch truck to keep it running fast and happy.
As we told you in Part 1 of Dirt and Haul, our ’98
Dodge 2500 truck was formerly a ranch truck that
had been sitting for a few years without much use or
maintenance. That means the gaskets and seals had
a chance to dry out, crack, and start leaking. Our
12-valve left a few marks wherever we parked it for
more than a few minutes. On top of this, the oil leaks
could be a fre hazard for the truck, and also the oil
could break down rubber parts like motor mounts or
even the rubber in the harmonic balancer. The guys
at Diesel Power Products knew our truck had been
neglected for a few years, and who better than them to help us get it back into shape. They began by pulling the valve covers and timing chain cover to address a few issues and reseal these parts.
Now, we’ll show you all the goodies tossed at the mighty 12-valve Cummins so the venerable oil burner would make plenty of power and maximize fuel efficiency. To do so, the guys at Diesel Power Products assembled a package that included FLO~PRO, AIRAID, Diesel Power Products, and BD Diesel Performance parts that would make any diesel enthusiast happy. Follow along as we tune the engine with new injectors, fuel plate, exhaust valvesprings, a new governor spring kit, a free-flowing exhaust, an adjustable wastegate, and a new intake system, as well as a few maintenance items. All in all, we couldn’t be happier with the new tire-smoking power all while retaining darn good fuel economy—when not doing burnouts.
Step By Step
Speaking of harmonic balancers damaged by leaking oil, here is our old balancer. The rubber was so swollen and damaged from the oil leaks that the balancer was spun and damaged enough to act like a mill on the crank position sensor. The crank position sensor was damaged enough to quit working which prompted the computer to shut down the gauge cluster and the alternator to quit charging. Luckily the truck still ran as long as we had battery reserve. That made for an interesting trip to Diesel Power Products’ Spokane Valley, Washington, shop from Arizona. Clearly, we and the truck made it but not without a little drama.
The only modifications that our ’98 Dodge had when we got it was an old BD Diesel exhaust brake, trailer brake controller, a few dings and dents, and a set of old worn-out aftermarket wheels. That means that we always suspected that the killer dowel pin was still in place and in danger of ending our 12-valve’s days. For those of you who are not familiar with the killer dowel pin, know that ’94-’98.5 12-valve Cummins engines have it. When the engine was assembled, a steel dowel helps align the aluminum timing gear housing. With use and vibration, the bore where the dowel pin resides can get larger. If this happens there is some chance that the pin can fall out. Many things can happen if the dowel falls out, the worst of which is if it gets caught between timing gears. If this happens, it will destroy the engine. Hence the killer dowel pin name.
Luckily for us and other 12-valve Dodge owners, Diesel Power Products will sell (and for us, install) a kit known as Killer Dowel Pin Kit from BD Diesel (PN 1040182, $111). Since the guys at Diesel Power Products were tearing into the front of the engine to address the oil leaks, the killer dowel pin kit was an easy install that will ensure years of use to come from our Cummins. A factory bolt is removed, and a small plate that comes with the kit is installed covering the dowel pin. The plate is then secured with the bolt preventing any movement.
We’re pretty sure that it has been scientifically proven that you can never have too much horsepower. That is true when it comes to a tow rig like our Dodge 2500. To that end, the guys at Diesel Power Products next installed a set of BD Diesel 60hp injectors for ’94-’98.5 12-valve Dodge Cummins (PN BD-1040295, $817). These tuned injectors replace our factory injectors, and the “60hp” in the name refers to the fact that these parts will increase rear wheel horsepower by, er, 60 hp.
Our ’98 Dodge has a Bosch 7100 fuel pump also known as a P-pump. By adding a BD Diesel #8 fuel plate (PN BD-1040193, $237), more fuel is delivered to the larger injectors and the horsepower and torque output goes up—rapidly. By adjusting the position of the fuel plate back and forth, you can change how much fuel gets sent to the injectors.
Luckily, the guys at Diesel Power Products know how to adjust this fuel plate so that our truck makes more power but still runs clean. The fuel plate also comes with installation instructions for those of you who might do this at home.
From the factory, our Dodge would only rev to about 2,000 rpm when the power and torque quickly dropped below usable levels. To remedy this, the guys at Diesel Power Products removed our factory governor springs and installed these BD Diesel 4,000 rpm governor springs (PN BD-1040185, $237). Once installed, these springs should allow our 12-valve to make power at higher rpms. This is helpful for building throttle response in a manual transmission truck (like ours) that is used for towing (as we plan to) especially when towing on grades and hills.
To help improve the effectiveness of our old BD Diesel exhaust brake, Diesel Power Products also recommended installing the BD Diesel 60lb Exhaust Valve Springs Kit (PN BD-1030060, $85). These springs (on the left) replace our 12-valve’s factory exhaust springs that are not up to the heavier loads placed on them when exhaust pressures climb during exhaust braking. This is vital to a truck that will tow down hills where the truck and trailers brakes can get overworked without use of an exhaust brake.
Speaking of exhaust brakes, our old BD Diesel exhaust brake was not working when we drove the truck up to Diesel Power Products. After disassembling and cleaning up the electronic solenoid and vacuum actuator along with the addition of new vacuum lines the exhaust brake now rumbles and slows the truck with ease as intended. Diesel Power Products also installed a BD Diesel Adjustable Wastegate (PN 1047150, $174) to our turbo. This part helps keep the bypass valve closed, raising boost levels for increased performance.
Behind the turbo, exhaust brake, and new wastegate, Diesel Power Products installed a FLO~PRO 4-inch Turbo Back Exhaust System. This allows our 12-valve with improved performance to exhale better than with the restrictive and worn stock exhaust system. The FLO~PRO exhaust has a nice rumble that is neither loud nor obnoxious but does remind us (and passerbys) that the Dirt and Haul Dodge means business.
If exhaling exhaust from our truck’s 12-valve Cummins is important, then you know getting fresh air into the engine is also vital to our new and improved engine performance. To handle the extra flow necessary and air cleaning duties, we turned to our friends at AIRAID. The company supplied us with its MXP Series Intake System (PN AR300-269, $369.90) with SynthaFlow oiled filter for ’94-’02 Dodge Ram 5.9L Cummins diesel. The system installed easily and can provide up to 37 hp and 56 lb-ft of torque over the stock intake system when installed on a modified 12-valve.
Making a big deal about getting air in and exhaust out of our 12-valve Cummins does not make much sense if there are air leaks in the intercooler boots. Since our Dodge is somewhere near 17 years old, the factory boots on the turbo and intercooler system could have leaks. Even pinhole leaks in these boots could cause a drop in power or efficiency. To avoid any such issues, Diesel Power Products installed one of its Replacement Intercooler Hose Kits in black with stainless clamps (PN DPP-OH160-BlackC, $207) for ’94-’02 Dodge 5.9L Cummins. With any luck, these boots should last for the next 20 years.
Once all buttoned back up, our ’98 12-valve Cummins was nearly ready to fire back to life but not before the guys at Diesel Power Products replaced the fuel filter for good measure. Since then, we have also been running Diesel Power Products Unlimited F-Bomb fuel additive with every fuel up. The truck runs great and makes a lot more power, meaning we can now handle almost all dirt roads and hauling duties.
Just in case you doubted us or Diesel Power Products’ ability to tune a 12-valve, here is some evidence that the old Dirt and Haul Dodge really hauls! Our poor Toyo tires!