Cummins B Series engine

General engine features

The B-series features engine bores machined directly into the block (rather than the wet liners used on earlier Cummins engines). It was also set apart by the use of a shallow one-piece head, requiring closer tolerances than in other Cummins products. The engine was first manufactured in Rocky Mount, North Carolina, and other plants were later added in Mexico, Turkey, and Darlington, UK.

Every Cummins powered Dodge Pickup (since initial production in 1989) has come equipped with a turbocharger. It uses a gear-drive camshaft for extra reliability. Also specified is a deep-skirt engine block and extra-strong connecting rods. A Holset turbocharger is used. The original B Series was updated with 24 valves and an electronic engine management system to become the ISB in 1998.

3.9L/4BT

The 3.9L/4BT Cummins is an engine in the same family as the 5.9 liters (360.0 cu in) Cummins turbodiesels. The 3.9L/4B is an inline four-cylinder turbodiesel that was popular for many step van applications, including bread vans and other commercial vehicles. It has also gained popularity as an engine swap into smaller trucks. The lowest powered 4B produces 55 hp (41 kW).

6BT

The 5.9 liters (360.0 cu in) 6BT, aka the Cummins "12-valve" was the first member of the "B" engine family to be used in a light truck vehicle. The 6BT used Robert Bosch GmbH fuel systems, injector, and VE rotary pump and P7100 inline injection pumps. Some early 6BT's were supplied with CAV rotary pumps instead, before the Bosch system became the sole standard. This engine started life in 1984 designed as an agricultural engine, for use in Case agricultural equipment. After 1989, the 6BT engine was used in light duty, medium duty and select heavy duty trucks and buses.

Appearing in the 1989–1998 Dodge Ram pickup truck, it became a popular alternative to the large V8 gasoline engines normally used in full-size pickup trucks, since it produced the torque at low engine speeds, and significantly better fuel mileage. During that time, the Dodge Ram was the only diesel pickup that did not rely on glowplugs for cold weather starting.

ISB 5.9

The 5.9 liters (360.0 cu in) ISB (Interact System B) is one of the largest straight-six engines used for light truck vehicles, and the improved high output 600 version was on the Ward's 10 Best Engines list for 2004.

One unusual feature of the ISB is that it is a multi-valve pushrod engine design. The engine displaces 5,883 cubic centimetres (359.0 cu in), with a 102.0 millimetres (4.02 in) cylinder bore and 120.0 millimetres (4.72 in) piston stroke. A turbocharger is used to increase the output in the high-compression (17.2:1 in recent versions) diesel. It is an all-iron engine with forged steel connecting rods, an assembled camshaft, and a cast aluminum intake manifold. The engine is produced in Columbus, Indiana.

The ISB uses electronically controlled Robert Bosch GmbH fuel systems, unlike the 6BT systems which were mechanical. Early ISB engines utilize Bosch injectors and a Bosch VP44 high pressure pump. Later ISB designs have common rail fuel injection, Bosch injectors, and a Bosch CP3 high pressure pump.

QSB

The 5.9 liters (360.0 cu in) QSB (Quantum System B) is the off road, heavy duty version of the ISB. Typically used in marine, agricultural, and construction applications, these engines share many of the same parts as the ISB and utilize the same Bosch fuel system.

Dodge Ram ISB

Midway through model year 1998, the Dodge Ram switched from the 6BT to the ISB to meet updated emissions requirements. Like other ISB's, these engines started out using the Bosch VP44 rotary injection pump. The VP44 setup meant that timing and fuel could be precisely controlled, which led to cleaner emissions. However, VP44 failure rates were higher than the older P7100 injection pump. The compression ratio in these engines was 17.2:1. The 1998–2000 ISB was rated at 215 horsepower (160 kW; 218 PS) and 420 pound-feet (569 N·m) when equipped with the 47RE automatic transmission. The 1998 ISB was rated at 235 horsepower (175 kW; 238 PS) and 460 pound-feet (624 N·m) when equipped with the manual transmission. The 1999–2000 ISB was rated at 235 horsepower (175 kW; 238 PS) and 460 pound-feet (624 N·m) when equipped with a manual transmission. For the 2001–2002 model years, a standard output and a high output ISB Cummins engine were offered. The standard output, which was the same as the previous engines was rated to 235 horsepower (175 kW; 238 PS) and 460 pound-feet (624 N·m) when equipped with either a manual transmission or automatic. The high output ISB was rated at 245 horsepower (183 kW; 248 PS) and 505 pound-feet (685 N·m), with only a NV5600 six-speed manual transmission available. The high output engine was different in a few ways from the standard output engine; it had higher compression (17.1:1), powdered metal valve seat inserts, a larger flywheel, the Bosch fuel system was reworked to allow higher fuel flows, and fuel-injection timing was altered.

Dodge Ram ISB CR

For the 2003 model year, the Cummins was introduced with Bosch high pressure common rail fuel injection, again increasing power output. On automatic equipped vehicles, the 47RE was upgraded internally to increase durability and torque capacity, now known as the 48RE. The 2003 rating for the Dodge truck was released at 305 horsepower (224 kW; 308 PS) and 555 foot-pounds (752 N·m). Midway through the 2004 model year, the Cummins 600 was introduced, producing 325 horsepower (242 kW; 330 PS) at 2,900 rpm and 600 pound-feet (813 N·m) at 1,600 rpm. This engine was noticeably quieter than the previous engines.

ISB 6.7

The B6.7 is the latest version of the B Series. It is currently the largest straight-six engine produced for a light duty truck. It produces 350 horsepower (261 kW; 355 PS) and 650 pound-feet (881 N·m) in the 2007.5 and newer Dodge 2500/3500 pickup trucks with the Chrysler-built six-speed 68RFE automatic transmission built at the Kokomo Transmission plant in Kokomo, Indiana. Engine torque is slightly reduced with the Mercedes G56 6-speed manual transmission at 350 horsepower (261 kW; 355 PS) and 610 pound-feet (827 N·m). The 2007 and newer 3500 Cab & Chassis trucks only get the 305 horsepower (227 kW; 309 PS) and 610 pound-feet (827 N·m) version of the B6.7, whether it has the Aisin AS68RC or the Mercedes G56 6-speed manual transmission. As for the 2008 4500/5500 medium duty Chassis Cabs or the Sterling Bullet Trucks, they receive the 350 horsepower (261 kW; 355 PS) and 610 pound-feet (827 N·m) version of the B6.7, whether it has the Aisin AS68RC or the Mercedes G56 6-speed manual transmission. Late model 2011 Ram trucks produce 350 horsepower (261 kW; 355 PS) and 800 pound-feet (1,085 N·m), with the exhaust brake rating boosted from 150 horsepower (112 kW; 152 PS) to 222 horsepower (166 kW; 225 PS).

Changes over the 5.9

There are many changes over the previous B5.9 for the Dodge truck, the most obvious being the larger displacement. The B6.7 had an increase of cylinder bore and piston stroke to 4.21 inches (106.9 mm) and 4.88 inches (124.0 mm) stroke, respectively, thereby giving a displacement of 408 cubic inches (6,686 cc).

Development

The 2/3-version of the ISB is the 4-cylinder 4.5-liter at 185 hp, used in the New Routemaster, a series hybrid diesel-electric doubledecker bus in London.