|BorgWarner Morse Tec’s CTA creates cam torsionals from the opening and closing of the valves. Click to enlarge.|
BorgWarner will supply Cam Torque Actuated (CTA) variable cam timing technology for the upgraded Ford Duratec 3.0-liter V-6 engine, debuting in the 2009 Ford Escape. BorgWarner Morse TEC’s new, patented technology improves engine performance and fuel economy while reducing emissions.
Unlike traditional cam phasing methods which typically use engine oil pressure to rotate the camshaft, BorgWarner’s CTA technology captures the existing torsional energy in the valve train to accomplish this event, similar to a hydraulic ratchet.
CTA cam phasers operate more quickly and under a wider range of engine speeds and temperatures than traditional oil pressure actuated cam phasers. These factors allow CTA variable cam timing to more efficiently improve fuel economy, increase horsepower and reduce emissions.
According to BorgWarner, benefits of the CTA technology over oil-pressure actuated phasing include:
- Very low oil consumption (0.2-0.4 L/Min); a larger oil pump is not required for CTA phaser;
- Less susceptible to oil aeration due to lower oil consumption;
- Fast actuation rates at idle speeds down to 500 rpm (150°/sec) and at low oil pressure (5 psi, 150°/sec);
- Minimal or no changes to cylinder head and block;
- Actuation during cranking (move back to base timing while starting);
- Low oscillations at hot idle conditions;
- Less sensitive to oil temperature and pressure variation;
- Greater than 60° range of authority; and
- Adapts to existing oil pressure actuated phaser control system.