As the first step in a slow ramp-up to full production, International Truck and Engine Corp. says it is beginning to take orders for heavy-duty trucks powered by its new proprietary MaxxForce 11L and 13L diesel engines. Under a joint development agreement, the new engine family is based on a MAN diesel and re-engineered with all new fuel and air systems to meet U.S. emissions requirements.

The first engines have already been built in MAN's Nuremberg, Germany, plant and shipped to International's Huntsville, AL, engine plant for some final assembly work, said Thomas Baughman, vp & gm of the OEM's Heavy Vehicle Center.

From Huntsville, the new engines are being shipped to International's truck plant in Garland, TX, where the first units will be installed in TranStar regional tractor models later this month. Within a month, the plant will also begin building severe-service WorkStar models with the MaxxForce engines. It's expected that MaxxForce installation on the two truck models will be split evenly between the 11L and 13L diesels.

In the second phase of the ramp-up, International's Chatham, ON, truck plant will start building ProStar linehaul tractors with the proprietary engine in mid-March, according to Baughman. Most will be powered by the higher displacement version.

By the end of April or beginning of May, the Huntsville plant will start production of the MaxxForce diesels, eventually taking over all North American production from the German plant.

The MaxxForce 11 is being offered in 330-, 370- and 390-hp. ratings producing peak torques ranging from 1,250 to 1,400 lb.-ft. The MaxxForce 13 ratings are 410, 430, and 475 hp., with peak torques between 1,450 and 1,700 lb.-ft.

Technical highlights for both include a high-pressure common-rail fuel system, twin-series turbo-chargers with an inter-stage cooler, and a new heat management system that electronically controls coolant flow. The two displacements will offer six models with ratings ranging from 330 to 475 hp.