Ford's new Duratec 23E engine, first introduced in the 2003½ Ford Focus PZEV (Partial Zero Emissions Vehicle) in California, New York and Massachusetts and now available nationwide, is both powerful - producing 151 horsepower at 5,750 rpm and 154 pounds-feet of torque at 4,250 rpm - and exceptionally
clean.The engine helps Focus meet California's Super Ultra-low Emissions Vehicle (SULEV) standard, which allows vehicles to emit only one pound of smog-forming pollution over 15,000 miles of driving. That's good enough to earn the car a perfect "10" on the U.S. Environmental Protection Agency's Guide to Green Cars. The car also has zero fuel system evaporative emissions. EPA estimated fuel economy is 25 mpg city and 33 mpg highway with the standard five-speed manual transmission and
24 mpg city and 30 mpg highway with the optional four-speed automatic.
"The Focus PZEV and the Duratec 23E are technological breakthroughs that deliver real-world environmental benefits without asking consumers to make a single compromise in performance, driving range, refinement or practicality," said John Sidelko, Focus chief engineer.All 2.3-liter Focus models in 2004 are identical to the Focus PZEV. They share the same emissions hardware, fuel system components and
powertrain calibration. However, the emissions are slightly less clean outside of California because of that state's unique fuel formulations.
Power, Refinement and Low Emissions
The new engine achieves its impressive level of performance, refinement and low emissions through careful design of the engine block and cylinder heads, air and fuel intake systems, powertrain controls, combustion chambers and exhaust system. The Duratec 23E cylinder block is a precision aluminum
casting with a deep skirt that extends well below the crankshaft center line to improve bending stiffness. A separate cast aluminum alloy ladder frame carries the lower bearing shells. This casting is secured by 10 bolts, one on each side of the bearing. Dry, cast-iron cylinder bore liners are cast into the block. A structural ribbed aluminum oil plan and cast alloy front cover further stiffen the block and reduce noise transmission.The extensive use of aluminum components and direct mounting
of accessories to the engine block helps to reduce the total installed weight of the engine by 40 pounds, or 12 percent, compared with the Ford 2.0-liter Zetec I-4 engine.
Cylinder Head and Valve Train
The dual overhead cam (DOHC), four-valve-per cylinder head design uses direct-acting mechanical bucket tappets and an aluminum alloy "high flow" cylinder head with press-fit valve seats that help to improve long-term sealing.Valves and tappets are individually graded
for consistency. This assures that proper valve clearances are maintained over the engine's life. Lobes on the chain-driven camshafts are chilled during manufacture to harden them. These actions help eliminate the need for valve adjustments throughout a useful life of 150,000 miles. Each cam runs in five cam bearings, for smooth and quiet operation.Intake valve diameters are 35 millimeters, with 30-millimeter exhaust valves. They are mounted at an included angle of 29 degrees to each other in
an asymmetric arrangement - the intake valves are 19 degrees from vertical and the exhaust valves are 10 degrees from vertical. This allows the spark plugs to be mounted near the center of the "pent roof" combustion chamber, a design that promotes circular flame propagation and improves fuel economy, especially under partial load.The camshafts run directly in the aluminum cylinder head and are driven by a "silent" chain for quieter operation. A spring arm maintains proper
tension and a hydraulically-activated composite damper controls chain movement. The camshaft cover is made of cast aluminum alloy to contain valve train noise and assure warp-free sealing for life.In addition to designing a durable and quiet-running engine, engineers worked to make engine components as fuel-efficient and lightweight as possible. A good example of this is the new piston, ring and connecting rod assembly, which provides about 15 percent weight advantage compared with other
modern engines. Other benefits include superior NVH, lower friction (or parasitic losses) and a free-revving engine characteristic.The electronic distributor-less coil-on-plug ignition system includes a cylinder knock-control system that continuously adapts the engine's operating parameters to optimize performance and economy.To enhance fuel efficiency, the engine uses 5W20 SAE (ILSAC GF-3) grade oil for reduced resistance to flow, and operates at a relatively low idle speed of 700 rpm.
Maximum engine speed is 7,000 rpm.
New Intake and Exhaust Manifolds
The computer-designed intake manifold is a prime example of the attention to detail that went into the new engine. It is fully symmetrical, lightweight and made of friction-welded plastic to reduce flow friction and stay cooler than cast metal. This design allowed engineers to "sculpt" the sound of the 16-valve engines to be sporty yet refined.Within each of the manifold's four runners is a
butterfly valve that restricts the air passage at low speed. This improves low-speed efficiency by inducing "tumble" or turbulence to accelerate the flow of the air/fuel mixture into the combustion chambers. At higher speeds, the butterfly valves open fully to meet the engine's requirement for more airflow.The intake system also features a new, solid-state temperature and pressure sensor, which makes more precise air mass calculations possible. These are constantly relayed to the
electronic powertrain control module for efficient engine operation.The powertrain control module also controls a new electronic exhaust gas recirculation (EGR) system that precisely meters the addition of burned exhaust gases to the intake charge. The extra mass of this inert gas in the intake charge acts as a heat sink to reduce combustion temperatures, which in turn helps reduce the engine's nitrogen oxide emissions.The rear-facing, four-into-one exhaust manifold is formed of tubular steel
which heats up faster than a conventional cast-iron unit. The catalysts are mounted very close to the manifold, so they heat to operating temperature quickly to reduce cold-start emissions. The catalysts themselves are a high density design that has more surface area than conventional designs to help reduce tailpipe emissions.
A new four-hole fuel injector design delivers a highly atomized-spray pattern directly toward the twin inlet ports of each cylinder for
more spray penetration, better atomization and less cylinder wall wetting than a single-hole injector. This in turn translates into good drivability and lower emissions. Sequential electronic fuel injection control injects precisely measured quantities of fuel into each cylinder individually at the optimum point in each combustion cycle.To help eliminate evaporative emissions, engineers designed a unique air intake system that includes a carbon trap to collect vapors from any residual fuel
left in the intake manifold at engine shut off. Other features that help eliminate evaporative emissions are a stainless steel tank, along with upgraded stainless steel fuel lines and connectors.
Power, Refinement - and Affordability
For 2004, the new Duratec 23E is available on all four Focus body styles (three- and five-door hatchbacks, sedans and station wagons) in 45 states, and it will be the standard engine in all Focus models, except for SVT products, in the states of
California, New York, Massachusetts, Maine and Vermont. Base MSRPs for 2.3-liter models, including destination and delivery, range from $13,455 for the Focus ZX3 to $18,360 for the Focus ZTW station wagon.In addition to the California or Federal emissions warranties, all Focus models, including the SVT Focus, are sold with a no-charge five-years or 100,000-mile limited powertrain extended service plan.
Wide Range of Engines and Applications
The new Duratec I-4 family is built
around a highly flexible architecture that can meet a wide range of vehicle needs around the world. More than 100 variations are possible, including designs optimized for fuel economy, low emissions, sporty performance or torque.Ford eventually expects to build more than 1.5 million of these engines annually in displacements of 1.8- 2.0- and 2.3-liters in various vehicles. This would account for 20 percent of Ford's annual world-wide production of 7 million engines."There's a revolution
going on under the hood at Ford," said Dave Szczupak, vice president, Powertrain Operations, Ford Motor Company. "We are introducing an unprecedented number of new powertrains between now and the end of the decade. The things we are doing today will assure that we continue to deliver great powertrains and great vehicles to our customers well into the future. "The new engine family also is leading the way in modern, cost-efficient manufacturing. Four plants on three continents
will build Duratec I-4s, and all will benefit from the efficiencies and quality improvements offered by flexible manufacturing techniques.
Note: The new Duratec 23E engine will not be available in Canada.