The MaxxForce DT (formerly known as the DT466) is built at Navistar's Melrose Park, Illinois, facility. The 80-acre plant was originally built by Buick in 1941 to produce engines for the B-24 Liberator bomber. The plant was sold to International (then known as International Harvester) in 1946, following the end of World War II for $1.00. Here, an older 12-valve version of the DT466 (DT466E) is being assembled along with the newer, 24-valve MaxxForce DT engines. International still produces the DT466E version (shown) for export customers in countries with lower emissions standards. The MaxxForce DT (formerly known as the DT466) is built at Navistar's Melrose Park, Illino If you've been keeping up with our recent engine plant visits ("History in the Making," Nov. '10, "Duramax Factory Tour," Dec. '10) you might've been expecting to see us tour Ford's new 6.7L Power Stroke facility. And while that is in the works, we've decided to showcase another extraordinary diesel engine many of our readers are familiar with: the MaxxForce DT (466ci inline-six) that Navistar builds for its International-brand medium-duty trucks and other global applications. Some of you recognize this engine because it has made more than 2,000 hp and withstood more than 200 psi of boost in the tractor-pulling world. Some of you know it as the powerplant of choice for school buses, dump trucks, plow trucks, and box trucks. And some of you have personally seen one hit the million-mile mark. After 40 years of production, it's no secret why the DT466 earned its legendary status for power, efficiency, durability, and serviceability. The DT Timeline The engine debuted in the agricultural world in 1971. Its first application powered IH 4166 four-wheel-drive tractors. It made its way into on-highway applications in 1975. Due to increased emissions standards during the last two decades, the injection systems found on the DT466 have gone from mechanical to HEUI to its current electro-hydraulic (G2) injection system. Exhaust gas recirculation and diesel particulate systems also now come as standard equipment. However, the overall engine platform has remained the same, and older versions are still produced for use all across the globe. As we watched the engine's assembly process unfold at Navistar's Melrose Park, Illinois, plant, it was obvious why the DT466 has become world-renowned. DT466 Facts B50 Life: 550,000 miles Power Levels: 185 hp to 345 hp (commercial), 375 hp (military) Builders: UAW Local 6 Engines Built: 2 million Engine Plant Size: 1.5-million square feet Most Common Application: School buses, medium-duty trucks DT466 Production (mechanical injection): 1971 to 1993 DT466E Production (HEUI injection): 1994 to 2003 DT466E Production (G2 fuel system): 2004 to present MaxxForce DT Production (G2 fuel system): 2006 to present The cast-iron blocks are cast at Navistar's foundry in Indianapolis and arrive at Melrose Park looking like this. The first stop along the assembly line entails getting all head bolt and coolant passages machined. Each finished block weighs 400 pounds. The cast-iron blocks are cast at Navistar's foundry in Indianapolis and arrive at Melrose Once the blocks go through their initial machining process, each one is flipped over and the ductile-iron main bearing caps are installed and torqued to spec. Once the blocks go through their initial machining process, each one is flipped over and t Next, each cylinder is counter-bored (arrow) to accept a wet sleeve further down the assembly line. The task is performed by machine in an enclosed, watertight compartment. The folks at International were kind enough to open it up and let us get a photo. Next, each cylinder is counter-bored (arrow) to accept a wet sleeve further down the assem Moving to the next fully enclosed station, the main-bearing surfaces are line-bored to ensure the main bearings are in perfect alignment. This process allows the crankshafts to spin as freely as possible. Moving to the next fully enclosed station, the main-bearing surfaces are line-bored to ens Each camshaft bushing is located and installed robotically. The machine finds the oil hole and double-checks to make sure the correct bushing is driven into each bore. The next station sees that each block is outfitted with all the piston-cooling nozzles. Each camshaft bushing is located and installed robotically. The machine finds the oil hole The blocks then get cleaned and flipped upside down once again. The main caps are removed, and the crankshaft and main bearings are installed. The main bearing caps are then torqued for good, and the following station confirms that the crankshaft's endplay is within spec. The blocks then get cleaned and flipped upside down once again. The main caps are removed, International receives its raw, forged-steel crankshafts from the Japanese company Sumitomo (which also forges the 6.6L Duramax crankshafts). During the machining process, the rod journals (crank pins) are induction-hardened for increased wear resistance. Finished crankshafts weigh approximately 180 pounds apiece. International receives its raw, forged-steel crankshafts from the Japanese company Sumitom The only difference between the MaxxForce DT, MaxxForce 9, and MaxxForce 10 engines is in the stroke of the crank (and the utilization of shorter connecting rods, respectively). All three engines share a bore of 4.59 inches. However, the crankshaft used in the MaxxForce 9 and 10 (shown) brings their stroke to 5.75 inches (versus 4.68 inches for the MaxxForce DT), making them both 570ci engines (9.3L). All three engines are produced along the same assembly line. The only difference between the MaxxForce DT, MaxxForce 9, and MaxxForce 10 engines is in Once the ladder assembly (bed plate) is installed on the bottom end for increased rigidity and vibration damping, the front cover is bolted up. Then the camshaft is installed in the block. All of International's camshafts are ground in-house and utilize roller followers to reduce friction. Once the ladder assembly (bed plate) is installed on the bottom end for increased rigidity The wet-sleeve architecture is what sets the DT466 engine apart from the competition. Its legendary design brought heavy-duty, Class 8 wet-sleeve technology to the medium-duty market. The sleeve's exterior is in contact with engine coolant, which provides consistent heat transfer and ensures the cylinders stay perfectly round. Essentially, the sleeve becomes a stand-alone cylinder, which allows for simple, in-frame rebuilds. All six sleeves are pressed into the block at the same time by machine. The wet sleeves are induction-hardened and plateau-honed as well. These two steps ensure durability and a consistent oil film for optimum lubrication and reduced ring wear. The wet-sleeve architecture is what sets the DT466 engine apart from the competition. Its Connecting rod and piston subassemblies arrive at piston-stuffing stations in six-packs. All connecting rods are forged-steel, fractured-cap units manufactured by Albon Engineering in the United Kingdom. There are three different pistons that can be used-depending on the intended application. For low-horsepower applications, a two-piece, aluminum piston is used. Mid-range power levels require a steel top, aluminum-skirted piston, and high-powered engines receive an all-steel piston. Human hands install the subassemblies; one worker stuffs the connecting rod into a cylinder, while a worker on the opposite side secures it to the crankshaft's rod journal. Connecting rod and piston subassemblies arrive at piston-stuffing stations in six-packs. A After a trip to the oil pan station, a head gasket is set on top of the block, followed by the massive, 250-pound cast-iron cylinder head. Tupy casts all the four-valve cylinder heads in Brazil, but the two-valve heads come from Navistar's foundry in Indianapolis. After a trip to the oil pan station, a head gasket is set on top of the block, followed by Human hands then set the valve lash and send the engine further down the line. Along the way, each unit receives its foam-molded engine harness (arrows), rocker box, and turbocharger. In this case, we're looking at a '10-model-year engine, which means it receives International's dual-sequential turbocharger system. This turbo setup consists of two fixed-geometry units with the high-pressure charger (up top) utilizing an external wastegate. Previous model years utilized a single, electronic variable response turbocharger (EVRT). Human hands then set the valve lash and send the engine further down the line. Along the w The next station was in charge of installing the '10 engine's electro-hydraulic G2 injectors. The second-generation, hydraulically activated fuel system was said to have increased fuel economy by 5 percent in '07 models, and it enabled diesel particulate filter regeneration without the need for downstream treatment. The next station was in charge of installing the '10 engine's electro-hydraulic G2 injecto Once the valve cover, intake plumbing, EGR cooler, and oil cooler are installed, engines are ready to be dyno'd. We should note that certain engines are painted differently. Most engines we came across during our visit wore black, with a couple wearing the old Navistar Blue paint scheme. The finished, dressed weight of a '10 model engine is approximately 1,900 pounds. Once the valve cover, intake plumbing, EGR cooler, and oil cooler are installed, engines a Unlike a lot of engine manufacturers, Navistar does not use selective catalytic reduction (SCR, or urea injection) in any of its '10 engines. The company has made it a mission to reduce NOx emissions in-cylinder, and at the source of the problem. Through the use of improved G2 injector technology and exhaust gas recirculation (arrow shows '04-to-'09-style EGR cooler, '10 model EGR coolers mount along the block next to the oil cooler), all of its engines are emissions-compliant and don't give the operator the additional task of monitoring exhaust fluid. Unlike a lot of engine manufacturers, Navistar does not use selective catalytic reduction Every engine produced at the Melrose Park plant is hot-tested on a dyno, where its power rating is verified. Dyno tests last between 7 and 9 minutes, and each session calls for an idle-up period, a full-power run (approximately half the length of the test), and then a cooldown. Every engine produced at the Melrose Park plant is hot-tested on a dyno, where its power r If you thought the International name sounded global, it is. Worldwide, the 466ci engine platform is used in multiple applications, ranging from gen-sets to military vehicles to Class 8 trucks. This batch of DT466E engines ('94 to '03 emissions version) was scheduled to be shipped to the United Kingdom for mobile power generation duty. If you thought the International name sounded global, it is. Worldwide, the 466ci engine p SOURCES Navistar 4201 Winfield Road Warrenville IL 60555 800-448-7825 www.navistar.com By Mike McGlothlin Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!