Ford Motor Co. got a little help from Denso Corp. in developing its first naturally aspirated direct-injection gasoline engine for North America.

The auto maker began work on the 2.0L DI 4-cyl. for the next-generation Ford Focus in early 2008.

Denso, the supplier of the DI system, was invited to join the program early on, a strategy Ford says it now is following for all development programs in order to better leverage the expertise of its supply base.

The early collaboration “helped things move smoothly and efficiently,” Dhyana Ramamurthy, manager-Engine Management Systems and Components, Denso International America Inc., tells Ward’s.

“It’s the first time in my experience that we’ve had that level of involvement,” he says.

An increasing number of auto makers are adopting DI technology as they scramble to meet looming federal fuel-economy mandates. Unlike traditional port-injection technology, DI systems spray fuel directly into the combustion chamber, optimizing efficiency.

Fuel is injected at pressures up to 2,150 psi (148 bar), about 35 times more than traditional port injection.

Months of calibration testing went into finding the “exact injector spray pattern” for the new 2.0L, says Scott Makowski, Ford’s I-4 engine manager.

Ramamurthy says Ford had a stringent list of requirements, including improving fuel economy without degrading performance.

“We have an injector that’s good on leakage, and that’s a key concern for carbon emissions,” he says. “We also have very good delivery accuracy across the speed-load range, (due to) an overall balancing of injector dynamics.”

The 6-hole injectors use internal solenoids to precisely switch the flow of fuel on and off. An electronic-control system varies the timing and intensity of the fuel delivery according to engine operating conditions.

The setup provides output rated at 160 hp and 146 lb.-ft. (198 Nm) of torque, while achieving an estimated 40 mpg (7 L/100 km) on the highway in the Focus when mated to a 6-speed automatic transmission and combined with Ford’s twin-independent variable-camshaft timing technology, which adjusts valve timing for optimum performance.

The mono-block system also is more compact than its key competitors, largely due to an innovative high-pressure pump. The single-plunger, cam-driven pump is 10% smaller than most, Ramamurthy says.

“It has probably the shortest profile on the market,” he adds. “And it’s highly efficient in fuel-delivery volumes, because there is a wide range of engine demands for the same pump.”

The system allows the engine to safely operate at a high 12:1 compression ratio, further enhancing power and efficiency. And unlike most direct-injection systems, the engine will be E85 flex-fuel compatible, Ford says.

Denso has developed similar DI systems for Japanese auto makers, but this is its first North American application.

The supplier’s close relationship with Ford landed it on the auto maker’s Aligned Business Framework program.

The ABF, launched in September 2005, is intended to strengthen relationships and collaboration between Ford and its suppliers.

“We wanted to show our value as a supplier, not just as someone who delivers parts,” James Moxlow, Denso’s account manager-powertrain, sales and marketing, says of working with Ford on the engine program.

bpope@wardsauto.com