3-Valve Technology is Featured in the ’04 Ford F-150

The new 5.4L Triton V8 engine that will power Ford’s next-generation

F-150 is designed with three valves per cylinder, variable-cam timing (VCT) and a host of other features that provide increased power along with improved refinement and fuel efficiency.

The net result is an engine that delivers 300 horsepower at 5,000 rpm, and 365 ft.-lb. of torque at 3,750 rpm, both best in class for a full-size pickup. The all-new, aluminum cylinder head - with two intake valves and one exhaust valve per cylinder for 24 valves in total - and a new cast-iron block balance this impressive power with better fuel efficiency and quieter operation.

This new technology builds on Ford’s award-winning modular V8 engine platform, while taking advantage of the capabilities offered by modern electronic controls.

The new 24-valve engine will be Ford’s first modular V8 to use VCT. This design allowed Ford engineers to optimize intake- and exhaust-valve actuation across the rev range. It represents the industry’s first mass application of dual-equal variable-cam timing, which shifts the intake and exhaust valve timing together.

In combination with precise control of spark timing, fuel injection and use of electrically controlled Charge Motion Control Valves in the intake ports, this technology produces improved power and torque, particularly at the lower engine speeds that are so important to applications such as towing and heavy hauling.

While the two-valve modular V8 line continues to deliver solid, efficient performance, Ford Motor Company’s premium V8 engines - such as the Mustang Mach I and Cobra, Mercury Marauder or Lincoln Aviator powerplants - have shown the performance potential of multi-valve arrangements.

The use of two intake valves enhances fuel-air mixing prior to combustion. This helps to squeeze all the energy out of each combustion event, improving power delivery and fuel efficiency.

Multiple valves also enhance the engine’s ability to "breathe" - that is, to move large volumes of air in and out of the cylinders - which is a key to generating maximum horsepower. Four-valve engines remain Ford’s first choice for luxury and high-performance applications, where horsepower and acceleration are prime concerns.

Yet they require considerable complexity, including two camshafts per cylinder head, which adds both weight and additional moving parts.

Ford engineers discovered they were able to get many of the benefits of a four-valve design - such as a central spark plug and symmetrical combustion chamber - using two intake valves and a single exhaust valve - with reduced weight and complexity compared with four-valve designs. The two intake valves allow peak airflow of approximately 350 cubic feet per minute, compared with about 250 cubic feet per minute in the 5.4L Triton V8, which uses a single intake valve per cylinder. This represents a 40% improvement.

With an all-aluminum head, single camshaft, magnesium cam covers and a clean-sheet design approach, Ford’s engineers were able to develop a three-valve head that has virtually no weight penalty over the two-valve V8 engines. The three-valve head is actually dimensionally smaller and somewhat lighter than the two-valve design for the 5.4L engine, while offering more rigidity and strength. It also is easier to manufacture, with simpler drilling angles and straight-machined surfaces.

VCT Offers Multiple Benefits
Ford’s new three-valve cylinder head uses a single overhead camshaft for each bank of cylinders. The cams press down on roller-finger cam followers to open the intake and exhaust valves, which are closed by coil springs as in all of Ford’s V8 engines.

Conventional camshafts are permanently synchronized with the engine’s crankshaft so that they operate the valves at a specific point in each combustion cycle. In Ford’s modular two-valve 5.4L V8 engine, the intake valve opens slightly before the piston reaches the top of the cylinder and closes about 60 degrees after the piston reaches the bottom of the stroke on every cycle, no matter what the engine speed or load is.

Variable-cam timing allows the valves to be operated at different points in the combustion cycle, to provide performance that is precisely tailored to the engine’s specific speed and load at that moment. The timing is set to allow the best overall performance across the engine’s normal operating range.

If conditions require earlier valve opening and closing, for example to achieve more low speed torque, the powertrain control module commands solenoids to alter oil flow within the hydraulic cam timing mechanism, which rotates the camshafts slightly. If the valves should open later, to generate more high-speed power, the mechanism retards the cams as needed.

The ability to control valve timing as well as spark timing allowed Ford engineers to design a combustion chamber with a higher compression level than in the two-valve V8 engines - again, while still using regular gasoline octane levels. Higher compression ratio produces greater efficiency, delivering more power and improved combustion efficiency.

Charge Motion Control Valves
At lower speeds and lighter loads, the new three-valve engine uses an electronically controlled metal flap at the end of each intake runner - eight in all. This Charge Motion Control Valve was specially shaped, through CAD modeling and testing, to speed up the intake charge and induce a tumble effect in the combustion cylinder. This causes the fuel to mix more thoroughly, and to burn quickly and efficiently, with reduced emissions, particularly at idle.

The CMCVs are controlled by an electronic motor, and open at a predetermined point as engine speed increases. At higher rpm, they do not affect the intake charge at all. This allows undisturbed maximum flow into the combustion chambers at wide-open throttle. The CMCV motor is sound insulated, so its operation remains transparent to vehicle occupants.

Other features of the 5.4L Triton V8 engine include:
• The pistons also have been shaped with noise reduction in mind. The pistons have longer side skirts than in the past, which helps to control piston movement and minimize piston slap.

• At the top of the engine, new magnesium cam covers offer the vibration-resistance of aluminum, at reduced weight. They are further isolated from vibration via rubber mounts. Reinforcing ribs cast into the cam covers, as well as a reinforcing plate in the underside of the covers, were both computer designed to minimize audible vibrations.

• The engine block itself is stiffer than in the past, through addition of computer-designed reinforcements cast into the block sidewalls, and thicker metal along the gasket surfaces. This, in combination with a new style oil pan made of a sandwich of metal around a plastic core, helps to minimize sound transmission through the bottom of the engine.