Auto Service World
Feature   August 1, 2003   by Auto Service World

Light Trucks Heavy on Engine Technology


There was a time not long ago when the light truck held a warm spot in many technicians’ hearts due to the simplicity of its underhood design, and engines that more than made up for in familiarity what they gave up in advanced technology. This is no longer the case.

Take the venerable Ford F-150, for example. Despite the fact that it has a reputation as a long-trusted workhorse, underhood is home to several engine packages as modern as just about anything in Ford’s passenger car lineup.

For the past few years, F-150’s standard Regular Cab and SuperCab were offered with a 4.2-litre OHV V-6 engine, which produces 202 horsepower and 252 foot-pounds of torque. It features a split-port induction system that optimizes fuel efficiency and engine response.

The 4.6-litre SOHC Triton V-8, which was standard with F-150 SuperCrew and optional with Regular Cab and SuperCab models, delivered 231 horsepower and 293 foot-pounds of torque. The single overhead cam (SOHC) design provides excellent valve control for dependable power and responsive performance.

For the past few years, there has been an optional 5.4-litre SOHC Triton V-8 engine putting out 260 horsepower and 350 foot-pounds of torque. In January 2002, this engine was named one of Ward’s Auto World magazine’s “Ten Best Engines” for the sixth year in a row.

Not good enough for Ford though.

So, for the 2004 F-150, the 5.4-litre unit is a 3-valve per cylinder V-8 engine that features variable-cam timing and a host of other technological goodies. Incidentally, it is built at the Essex Engine Plant in Windsor, Ont.

It is, says Ford, the most advanced V8 the company has ever built.

It is certainly a far cry from the company’s first V8, introduced in 1932, which featured a side-valve flathead configuration that was, in its day, a tremendous innovation.

The new overhead-cam 5.4-liter, 3-valve Triton engine incorporates technologies equally as advanced for today. The three-valve design also allows for a central sparkplug that allows complete, even combustion. New charge-motion control valves in the intake runners enhance air-fuel mixing at low rpm, improving low-end torque. Plus, it features an electronic throttle control system. Replacing the mechanical throttle linkage is an accelerator position sensor in the cabin, an electronic control circuit and an actuator at the throttle valve on the engine.

And, of course, nothing short of a distributorless, coil-on plug ignition system would do.

There is no secret that a great deal of these advancements are initiated to reduce emissions. The engine puts them to use in some innovative ways to achieve this.

A special “cold-start” strategy allows the new three-valve engine to bring the exhaust catalyst to operating temperatures more quickly, reducing emissions in the first minutes of operation.

The Charge Motion Control Valve flaps use computer-designed cutouts to induce turbulence in the air-fuel mixture at low engine speeds.

Variable valve timing reduces pumping losses, the work required to pull air in and push exhaust out of the cylinder.

This design automatically channels a portion of burned gases back into the cylinder, to improve efficiency and reduce emissions. In addition to eliminating the external exhaust gas recirculation (EGR) circuit, this design reduces temperatures inside the intake manifold. Cooler combustion reduces production of the pollutant NOx.

While this is just one example of changes underhood, all other light truck makers are taking a similar approach.

No longer can technicians, or counterpeople, assume that they’ll be able to ride the tide of unchanging technology, as long as their customers drive in, and work on, pickup trucks.


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