An engine that could: new engine resolves power and emissions questions

Concrete Producer, The, May, 2004 by Daniel Brown

Sometimes a fleet manager needs more power in the producer's mixers or dump trucks. The terrain may be demanding. He may want to pull pup trailers with his dump trucks. Of he may just desire more torque.

While these factors probably haven't varied too much, the tools to perform the work have. For example, there are new federal rules forcing truck and engine manufacturers to reconfigure their products to meet ever-tougher exhaust emission standards. New standards took effect in October 2002, and will only get more demanding in the not-too-distant future.

One answer to the fleet manager's need for higher horsepower in a truck-engine combination that meets EPA's Tier 2 standards is the new series of International 5000i trucks fitted with Cummins ISM 425V engines. These new 11-liter engines pump out 425 hp and 1550 pounds per foot of torque and are several hundred pounds lighter than other big-bore engines, says Chuck Good, Cummins Engine Co.'s director of national accounts for vocational markets.

And the good news is that International dealers are expected to have the new Cummins engines in 5000i Series trucks beginning in May. Production of the new ISM 425V was scheduled to begin in Jamestown, N.Y., in April.

International is the first truck builder to get the new ISM 425V, says Laura Wenzler, Cummins' general manager of OEM business. Prior to this, the ISM engine was only available far dump and mixer trucks in power ratings up to 385 hp. For higher horsepower engines, fleet managers had to go to the heavier Cummins ISX Series. With the advent of the new emissions rules in 2002, Cummins discontinued the N14 engine that was used by many severe educational fleet managers.

"The ISM 425V gives Cummins a huge advantage that they did nut have before," says Frank Raney, severe service marketing manager at International Truck and Engine Corp. "Now, that engine can serve a whole host of dump trucks, over-the-road heavy haulers, and the largest mixer trucks. It's a very nice dump truck engine; that's the horsepower rating they like. It competes well with the Caterpillar C12 and Mack's engines.

"Before this, International would have sold those customers an ISX engine, which was a lot heavier and more costly," says Raney. "The ISX is a 15-liter engine with ratings from 430 to 575 horsepower."

Good torque

Dennis Spoerlein is the fleet manager for McHenry Ill.-based Meyer Material Co. and runs upwards of 500 ready-mix trucks in northern Illinois and southern Wisconsin. Spoerlein's fleet has a number of Oshkosh front- and rear-discharge mixers which he's fitted with Cummins L10 and M11 engines.

A new 425-hp Cummins engine in a vocational truck should provide good torque. "Torque pulls the load, and horsepower gives you speed. With a fully loaded truck getting away from a stoplight, you need the torque," says Spoerlein.

To meet the new EPA emissions standards, most truck engines must run warmer than before, which means they need more cooling capacity from the truck manufacturers. For example, Cummins engines meet the new standards by using a technology called Exhaust Gas Recirculation (EGR).

Exhaust gas is removed from the exhaust stream, cooled, and put back into the intake side of the engine. As that gas mixes with the air and fuel, it inhibits the combustion process somewhat. The result: lower flame temperatures and lower levels of nitrous oxide emissions. "I have nut heard of major issues with the performance of those engines," says Raney.

>From International's perspective, Raney says most of the OEM's severe service trucks had oversized radiators and cooling systems before the new emissions rules. "International engines didn't have to change for October 2002," he says. "They were compliant and exempt from the edict."

Little changed with the 5000i Series to accommodate the new ISM 425V engine. "We did it in less than 90 days," says Raney. "It just required some new pipes for the cooling system."

International has a strong relationship with ready-mixed producers. "We have 40% of McNeilus' business," Raney says. The International 5500i is a set-forward front axle truck, often used for concrete mixers, and it optimizes axle capacities to meet federal bridge formulas that apply to U.S. highways and interstates. The 5600i is a setback axle version, often used for maneuverability around town. Both the 5500i and 5600i are used for mixer applications.

In addition, the 5000i Series has an aluminum cab, which Raney says mixer people favor because aluminum finishes resist the acid washes used to clean trucks. The 5000i Series is built especially for severe service applications; either single or double 12-inch-deep frame rails are available. By contrast, International's 7000 Series trucks offer single or double 10-inch rails.

Simple turbocharger

The ISM 425V engine features the simply designed Variable Geometry Turbocharger (VG Turbo) by Holset, a Cummins subsidiary. Other manufacturers use flexible vanes in their turbochargers, and they have dozens of wear parts that are constantly moving under intense pressure and heat.