New powerplant offers 600 hp., plus improved fuel economy. According to Cummins Engine Co., its Signature 600 -- the first truck engine to be designed around an advanced electronic control module (ECM) -- will change truck operators' perceptions about big horsepower: Namely, that high-horsepower engines necessarily mean increased fuel costs.

While conceding that most mainstream operators are not yet ready to move to an engine that cranks out 600 bhp. at 2,100 rpm and delivers 2,050 lb.-ft. of torque at 1,200, Robert Cordaro, Cummins Engine Co.'s executive vp and group president-automotive, says that "the industry trend for the 21st century clearly is in the direction of increased power."

At the introduction of the Signature 600 last month, Cordaro said that the new premium engine, which initially would be of interest to owner-operators and performance-minded small fleets, not only can operate on less fuel than an N14 525 Plus, but is capable of saving users as much as 0.5 mpg in fuel over the highest horsepower engines available to fleets in the early 1990s.

However, Cordaro also noted that demand for engine power, which has been increasing at a rate of 6 hp./yr., is now starting to accelerate. "Truck operators need extra power to increase vehicle productivity, meet competitive pressures, and satisfy drivers who want higher average vehicle speeds with reduced need to shift gears."

Citing the central role of electronics, Cordaro recalled that use of fuel, air, and combustion controls in the 1990s proved crucial in lowering emissions while increasing fuel economy and durability. "With the advent of the Signature 600 platform," Cordaro said, "Cummins further refined engine combustion technology. We've reached the point where an engine's fuel efficiency can now be decoupled from its rated power output."

While reluctant to get into the specifics of bore and stroke dimensions at this time (he did describe it as a 15-liter engine), Cordaro pointed out that the Signature 600 has an extremely high power-to-weight ratio. It tips the scales at 300 lb. less than an N14, and contains a third fewer parts.

The mechanical and electronic features that give the engine heightened responsiveness, better performance, and fuel economy are more important than its displacement details, he insisted. "Some of the electronic and hardware features it has will be incorporated into other Cummins products," he stated.

The most striking mechanical aspect of the Signature 600 is its single-head, dual-overhead cam system. Cam one drives the high-pressure (28,000 lb.) injection system for increased power, improved throttle response, and better fuel economy. Cam two actuates the intake and exhaust valves, as well as the Interbrake engine brake, which is capable of producing up to 600 retarding horsepower. The two-piece pistons, which are made of high-strength alloys, run in mid-stop cylinder liners that reduce cavitation and provide a higher tolerance to variations in coolant chemistry.

The unitized design of the Signature 600 eliminates many external parts. Engineers also worked to make one part serve more than one function where practical, and to incorporate multiple functions in the block and head. The fuel pump, fuel-filter head, and ECM, for example, are centrally located under a single panel. The injectors are the "open-nozzle" type, delivering noise and emissions benefits without requiring external plumbing.

The turbo's variable-output design, with special wastegate control, enables it to perform much like a variable geometry turbo. At low speeds it quickly pumps up pressure for engine responsiveness; at high speeds it manages air flow to maximize performance and efficiency while avoiding overboost.

The Signature 600's ECM manages fueling and timing for each cylinder, working in tandem with the injectors. In this new system, Cummins uses four solenoids (rather than six) located in the fuel system module adjacent to the fuel-injection cam. The layout allows the smaller-sized injector packages to be located directly in the center of the combustion chambers.

Designed to minimize the effects of parasitic losses, the new engine's electronic controls sense when the driver is going uphill. They are programmed to turn off accessories such as air compressors at those times so drivers can get maximum power.

According to Cummins, the Signature 600 is a low-maintenance engine that can go well over a million miles with advanced lube and filtration systems that enable the user to double the miles between service intervals and get 50,000-mi. oil drain intervals.

Carrier Transicold has introduced two versions of a new multi-temperature refrigeration system for insulated semis with moveable bulkheads, as well as a direct-drive system for midrange straight trucks.

The Genesis TM1000 and TM900 are high-capacity multi-temps for distribution-type reefer operators that run multiple-compartment trailers. Designed to maintain compartment temperatures in a range from -20degF to 80degF, the cooling capacities of the Genesis TM1000 and TM900 are 32,000 and 30,000 Btu/hr., respectively.

According to Carrier, the Genesis versions provide up to 80% more air flow than conventional multi-temp units. Evaporator coil arrangements cut defrost times in half, while remote evaporators cool up to 75% of a trailer from the rear, allowing high-turnover goods to be placed anywhere in the van and still be temperature-protected.

The larger Genesis version features the Carrier Transicold Ultra condenser, a microprocessor-based control, installation kit, generator, host evaporator, low-noise option, and HCFC-22 refrigerant, as well as single- and dual-discharge evaporators. The TM900 uses the Extra condenser, microprocessor, generator, and host evaporator.

Carrier's latest direct-drive unit for midrange trucks with insulated van bodies up to 16 ft. in length is the Integra 30S. Using the host vehicle engine as the power source to drive a 10.3 CID road compressor, the Integra saves approximately 600 lb. of weight compared to a Supra 422 with similar capacity. The unit provides 8,500 Btu/ hr. of cooling capacity over a temperature range of -20deg F to 80degF.

The Integra 30S differs from traditional direct-drive units in that its condenser and evaporator assemblies are not connected as a single unit. A split-construction design separates the main condenser housing from the evaporator section; refrigerant supply and return lines serve as the conduit between the two components. After extensive testing in Europe, the unit is now in full North American production.

The PowerSensor Micro400 is a hand-held analyzer that enables fleet technicians to quickly and accurately determine the condition of vehicle storage batteries.

Made by Midtronics Inc., the device has a digital display that shows battery voltage, available power expressed in cold cranking amperage (the amount of amperage the battery can deliver at 0degF for a period of 30 sec.), and a verbal assessment of the battery's condition.

Once its leads are connected to a battery, the PowerSensor Micro400 prompts the technician to input the battery's CCA rating. A CCA test is then conducted by means of an AC signal between the battery terminals. The conductance between the plates is electronically measured in about five seconds and compared against values for similar good batteries.

The PowerSensor tells the technician whether the battery is good, needs to be replaced or recharged, or is marginal. State-of-charge and temperature compensation allow batteries to be accurately tested even in below-zero temperatures.

Quaker State Corp. has signed an agreement with Alternative Gases LP to distribute Free Zone RB-276, a CFC-12 alternative.

Under terms of the pact, Quaker State will offer the refrigerant through its national network of distributors and Q Lube locations. At these locations, the refrigerant is available for purchase in 12-oz. cans and 30-lb. cylinders to certified fleet A/C technicians.

Known in EPA parlance as HCFC Blend Delta, Free Zone RB-276 is listed as an acceptable substitute refrigerant for retrofit and new uses under the agency's Significant New Alternatives Policy (SNAP) program. This assumes, of course, that use conditions meet EPA requirements.

According to an Alternative Gases spokesperson, RB-276 provides the cooling equivalent of R-12, but is less expensive to install in older vehicles. Moreover, it does not require barrier hoses, flushing of the A/C system, or PAG lubricant, which are typically necessary for successful R-134a conversions.