Description and principle of operation of the engine Duratec ST 2.0 l

The 2.0L Duratec ST engine is based on the 2.0L Zetec-E engine. Compared to the 2.0L Zetec-E engine, the following changes have been made to the design of this engine:

• Cylinder Block - Modified to include piston injectors.
• Cylinder Head - Intake Port: High flow design with new manifold connection. Exhaust port: - Standard port, but with secondary air supply to the back of the exhaust valve. Water jacket: Change in flow in the port area. Oil supply scheme for variable valve timing (valve opening or closing times). Installing a VCT solenoid valve (variable gas distribution) into the front camshaft bearing cap.
• Inlet Valves - 33.5mm bore with re-clearance to retain bridging and longer length for new port.
• Exhaust Valves - Standard bore but longer to accommodate the tappet on the intake side.
• Intake Camshaft - Increased lift and duration with variable valve timing. Pulse wheel to indicate the position of the camshaft.
• Exhaust Camshaft - Increased lift and duration.
• Tappet - A range of sizes with special classification to match the new valve length and revised cam shape.
• Valve Springs - Special for intake and exhaust valves to match the new valve length and revised cam shape.
• Piston group - Piston with a piston pin with a diameter of 20 mm. Connecting Rod: Forged construction with broken split line. Top Piston Ring: Internal slope to reduce bypass of combustion gases and negative ring end ovality to reduce wear.
• Camshaft cover assembly - Redesigned to accommodate new VCT solenoid valve. Camshaft cover assembly with gasket.
• Upper timing belt cover assembly - Redesigned to include VCT pulley.
• Front engine mount - Repositioning the mounting studs to accommodate the VCT pulley.
• Alternator Bracket - Redesign due to redesign of the engine mount.
• Intake Manifold - Manufactured in two pieces, replacing a one-piece fixed-length manifold. Collection chamber assembled. Complete housing - Collector - Injectors. Design with adjustable inlet lengths. The unit has short channels when the engine is off and then, after starting the engine, it switches to the position of long channels. At a frequency of more than 6000 rpm, the channels switch back to the short position.
• Throttle Body - Variable diameter up to 63mm.
• Nozzles - High flow, 224.8 g/min at 2.7 bar (normal pressure in the fuel rail)
• Fuel manifold - Revised design with integral damper and no fuel return line. Repositioning of the fuel manifold inlet port, requiring a new fuel supply hose to be installed.
• Flywheel assembly - Double mass flywheel.
• Clutch assembly - Friction disc of increased diameter. Pressure plate of increased diameter.
• Oil cooler - Modine type.
• Controlled gas distribution system - Controlled gas distribution unit assembly. Solenoid valve assembly
• Oil Separator Assembly - Internal modifications to improve performance under high cornering loads - to be incorporated into the base engine.
• Exhaust system - Tuned 4-2-1 system with a catalytic converter located under the oil sump.