The 2002-2005 Dodge Ram Heavy Duty Engines
Cummins 610 Turbodiesel
The Cummins 610 Turbo Diesel, available on 2005 models, was more powerful, and particulates and nitrogen oxides (NOx) were reduced to meet all states' emission standards - even California's. The piston combustion bowl and a high-flow, electronically controlled waste-gated turbocharger matched boost pressure with engine needs to reduce emissions. This solution did not require exhaust gas recirculation, avoiding the need for over 50 components.
More to the point for most owners, the 610 had, appropriately, 610 lb.-ft. (827 N•m) of torque starting at 1,600 rpm.
The Cummins turbodiesel also provided an average of 350,000 miles before an overhaul was needed, thanks partly to gallery cooled, high-strength aluminum pistons; gallery cooled, high-strength aluminum pistons, high-strength Inconel® exhaust valves and high-cobalt Stellite® exhaust valve seats, a high-strength exhaust manifold with multi-layer gasket between head and manifold; and forged steel, fracture-split connecting rods.
The Cummins 610 was quieter due to many noise reduction systems, including pilot injection - a short burst of fuel before the main injection which reduced the spike in combustion pressure for dramatically quieter combustion.
Doug Hetrick noted that the Cummins diesel was available on the Ram 2500 SLT and all 3500 models, according to Dodge's Web site; only the 610 was available when he tried the build-a-car feature, not the other Cummins diesels listed later on this page.
The 345 horsepower 5.7-liter HEMI Magnum V-8
The 2003 Dodge Ram 2500 and 3500 heralded the return of one of the most legendary names in automotive lore: HEMI. The new 5.7-liter HEMI Magnum engine was the standard engine on the Dodge Ram Heavy Duty, producing a class-leading 345 horsepower at 5,400 rpm and 375 lb.-ft. of torque at 4,200 rpm. It provided best-in-class acceleration and towing capability compared with competitive vehicles with similar size gasoline engines.
"We liked the elegance and simplicity of the HEMI design and it beats a dual overhead camshaft design in terms of torque and power for a heavy-duty truck," said Schaum. "We think that the central camshaft, pushrod design is the optimal solution for vehicles with large mass designed to carry heavy loads."
Although the HEMI name was linked historically to performance vehicles, its power, durability and torque made it an ideal and long-serving truck engine. Dodge debuted its original HEMI in 1953, and the very next year saw the first application of Dodge HEMI power in a heavy-duty Dodge truck. In 1954, Dodge offered the 241 cubic inch HEMI V-8 in its two-and-a-half ton K model. Just as today, Dodge was the only manufacturer offering a HEMI V-8 engine, which was an ultra-modern engine that could out-accelerate and out-tow its competition. Some things never change.
"This is one of the most technologically advanced engines ever engineered by the Chrysler Group," said Floyd Allen, Vice President, Product Powertrain Team. "Durability and power were key points for this engine, but the new 5.7-Liter HEMI Magnum has such advances as a composite integrated air fuel module and electronic throttle control. Its hemispherical head design allows the use of larger valves and provides better air flow to the combustion chambers. We were also able to reduce emissions and gain approximately an eight percent fuel efficiency improvement."
The all-new HEMI Magnum also featured cross-flow aluminum cylinder heads with hemispherical combustion chambers and investment cast, steel rocker arm actuated splayed valves for high air flow; two spark plugs per cylinder for fast, efficient combustion and improved idle quality; and a new direct ignition system with high-power coils ensuring consistent, complete combustion. A fully-balanced, cast, nodular iron crankshaft running in cross-bolted steel main bearing caps reduced deflection and vibration for reduced noise, vibration and harshness (NVH).
The Hemi engine hooked up with the 545RE five-speed automatic or a manual transmission.
Note: this information was current in 2002-2004. In 2005, the Cummins 610 replaced all other diesels in Dodge trucks, according to Doug Hetrick.
Not only was the Cummins Turbo Diesel the most powerful diesel engine available in a full-size pickup, it was also one of the most drivable throughout all operating ranges. Maximum torque for the common rail injected Cummins Turbo Diesel occured 400 rpm lower than the GM Duramax, and 100 rpm lower than the Ford Power Stroke. The Cummins Turbo Diesel engine also produced 20 percent more torque at 1000 rpm, and 10 percent higher clutch engagement torque than its predecessor. That related to noticeably better vehicle launch when towing and accelerating, better drivability, and fewer and smoother shifts. (In 2005, the 610 was introduced as well - see top of page.)
In addition to the High Output version, the Dodge Ram Heavy Duty was available with a standard Cummins Turbo Diesel, which also employed high-pressure, common rail injection. The standard Cummins Turbo Diesel boosted its horsepower rating to an impressive 250 horsepower at 2,900 rpm (up from 235 horsepower at 2,700 rpm) and produced an equally impressive 460 lb.-ft. of torque at 1,400 rpm.
The High Pressure Common Rail Cummins Turbo Diesel
Delivering 555 lb.-ft. of torque at 1,400 rpm and 305 horsepower at 2,900 rpm, the new 5.9-liter High Output Cummins Turbo Diesel was the most powerful turbo diesel engine available in the heavy-duty market when introduced in 2002, delivering a class-leading trailer towing rating of 23,000 lbs. (GCVWR). (It was superceded by the Cummins 6100 with 610 lb-ft of torque at 1,600 rpm - see top of page).
With nearly 75 percent of Ram 2500/3500s being sold with the Cummins Turbo Diesel engine option, it had one of the most devoted followings of any heavy-duty pickup. Cummins owners accepted nothing but the best, and the new turbo diesel delivers with improvements ranging from an all-new block to a new high-pressure, common rail fuel-injection.
The new 5.9-liter Cummins Turbo Diesel was so tough it was certified to a longer engine life than the diesels offered by Chevrolet and Ford, with an average major overhaul interval of 350,000 miles. An inline six, the new 5.9-liter Cummins had 25 to 30 percent fewer parts than typical V-8 diesels, which meant better reliability, critical when downtime could mean lost business and revenue. Additionally, oil drain/filter service intervals were doubled from 7,500 miles to 15,000 miles for schedule A service and from 3,750 miles to 7,500 miles for schedule B service.
New High-Pressure Common Rail Injection System
More than just the master of big twist, the Cummins Turbo Diesel was radically overhauled. Quietness, power and durability were hallmarks of the new Cummins. The new high-pressure common rail fuel injection systems designed for the 2003 Dodge Ram Heavy Duty used pilot injection - the injection of a small amount of fuel to start combustion - before the main, power-producing fuel charge was injected. This had the effect of smoothing out combustion pressure in the cylinder, which could be the primary source of low- and mid-range speed noise in diesel engines.
A gear-driven fuel pump delivered fuel to the rail and was electronically controlled to optimize fuel pressure at the individual injectors. The system provided injection pressures up to 23,200 psi (1600 Bar) and was less dependent on engine speed than traditional pump-line injection systems. The result was cleaner combustion and higher low-speed torque with better vehicle response and acceleration.
In addition to the use of pilot injection to smooth combustion pressure, the fuel-injection calibration - timing, pressure and quantity - was refined across the entire range of speeds and loads to ensure smooth, quiet combustion. The use of pilot injection during starting also provided gasoline engine-like cold starting capability (verified at temperatures as low as minus 40 degrees Fahrenheit during testing above the Arctic Circle).