e q u i p m e n t

Cummins Debuts Electronic C-Series Diesel Engines

Cummins has completed the electronification of its diesel engines with the introduction of the ISC, the electronically controlled, 24-valve version of its 8.3-liter, 6-cylinder model. Changes upgrade both emissions and performance, allowing the ISC to take over many of the applications of the lower-power options of the 10-liter L10.
ISC stands for Interact System, C-Series and refers to the combination of electronic fuel controls with interactive information processing. The technology coordinates functions between engine and vehicle systems such as transmission, antilock brakes and traction control, dashboard information and collision warning. It also provides links to Cummins INFORM, INSPEC and InRoads management software as well as other management systems. Cummins is also partnering with Amtech Transportation Systems to use radio-frequency tags on trucks with the Interact System engines.

NEW IRON, ELECTRONICS
The ISC has been extensively redesigned in the cylinder area and equipped with an all-new and patented mini common-rail fuel system. With breathing improvements from the 4-valve head layout and the central injector, the revised C-Series now has increased horsepower, improved response and better fuel economy, all while meeting 1998 emissions levels without any external aftertreatment of the exhaust.
The 24-valve head is all new. Other design improvements include a more rigid block, improved accessory drives and mountings, with the front engine mount relocated off the gearcase and onto the block. A new serpentine fan belt is self-tensioning for improved alternator and belt life even at higher accessory power requirements. A big feature of the new head design is the no-adjust overhead, helping lower overall cost.
A multi-piece exhaust manifold reduces stress at higher exhaust temperature levels, and an improved, wastegated HX40 turbocharger boosts power and torque. Improvements to the structure of the engine and the breathing, as well as the new fuel system, bring down overall noise levels 3 dB at maximum speed and 2 dB at idle.
The new engine is available with ratings from 215 to at 300 hp at its peak for on-highway applications, with torque ranging from 620 to 950 lbs.-ft. For fire and RV applications, the ISC goes to 350 hp and 1,050 lbs.-ft. Clutch engagement torque is up, too, to 500 lbs.-ft. and transient response is claimed far better than the old C-Series, making the engine a lot nicer to drive, says Cummins.
Much of the credit for the performance goes to the revised fuel system. The new design is different from that on the new 15-liter Signature 600 and designed for the smaller engines.
Critical to performance and durability targets is a 4-valve head. In the smaller engines with reduced bore dimensions, finding space for the valves and the central injector was a real challenge. This has been accomplished using electronic controls on the pump, and a conventional line and nozzle. The pump is rotary — effectively a common rail — with fuel pressurized with an internal pump and fed to an accumulator. Fuel is metered through a single electronic three-way valve then delivered to the correct injection line through a rotary distributor, all built into the pump — hence the name CAPS for Cummins Accumulator Pump System.
Cummins says the system can deliver the high fuel pressures necessary for current emissions compliance. An additional benefit of the common-rail accumulator is that fuel pressure is independent of engine speed, giving better control of emissions throughout the speed range. Electronic control of the accumulator pressure and the metering valve also allows for rate-shaping, the latest technology to promote close-to-ideal combustion and particulates control.
Electronics offer full authority control and the engine has full J1939 databus compatibility. The SAE J1939 allows for high-speed serial communications with other vehicle systems, most notably the transmission and braking and traction systems.
On-engine electronics allow for the full range of electronic features available on the big engines, plus some additional functions to accommodate vocational users and a broad variety of industrial applications. Other benefits claimed include a reduction in start-up white smoke and improved cold startability, a beefier torque curve throughout the range and lower noise levels.
It certainly pulls well, judging from the demo staged at the Las Vegas launch: Two Kenworth T800 dump trucks, side by side dragged up a 5% grade. The winner was obviously the ISC powered truck, but it beat out an L10-280-engined dump truck. And the ISC was loaded with an additional 500 pounds to compensate for the difference in engine weight — plus another 5,000 pounds additional payload.

DURABILITY, RELIABILITY
The ISC benefits from the 4-valve head as the piston rings see a more even temperature distribution across the combustion chamber and cylinder. Other reliability and durability improvements come from the redesigned front drive and gearcase, from the on-board electronics and from redesigns of both the lube and the cooling systems that increase fluid flows and filtration.
Along with the enhancements in life come reduced costs from longer oil drain intervals and the no-adjust overhead.
Another cost saver is the easy extraction of on-board data. Using the Amtech radio tags, a company can easily download information at a terminal gate, halting a truck for only a matter of moments for the data extraction and for any readbacks — such as resetting the counters and writing any new parameters to the engine. Cummins software allows for the reporting of this data to aid in vehicle dispatch, driver monitoring and training, and maintenance scheduling. It even offers additional functions such as tracking how long trucks are sitting in the terminal, for instance, to increase the overall productivity of a fleet.
Other potential savings come from application of the Cummins Centinel constant oil-change option that pushes drains to 300,000 miles and filter changes to 75,000 miles. And, because the ISC can do the work of a 10-liter engine, the installed cost in chassis offers further savings of as much as $1,500, with 500-pound payload gains over the life of the vehicle.