CYLINDER HEAD [SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US))]
CYLINDER HEAD [SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US))]
SM2565217
id0110u0000400
Outline
• With the adoption of the rocker arm (built in needle roller bearing), the sliding resistance has been reduced.
• With the adoption of the HLA, the valve clearance is maintained at 0 mm {0 in} at all times.
• The contact point of the rocker arm and cam is lubricated by the engine oil injected from the oil shower pipe.
• Because the SKYACTIV-G 2.0 and SKYACTIV-G 2.5 are implemented on the Miller cycle, the intake manifold vacuum is insufficient during retarded intake valve closing. To improve this, a vacuum pump has been adopted which compensates for the insufficient intake manifold vacuum. (See VACUUM PUMP [(US)].)
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Purpose, Function
• The cylinder head forms the combustion chamber and intake and exhaust ports.
Construction
• The lightweight cylinder head is made of aluminum alloy with excellent thermal conductivity.
• Designing a compact pentroof combustion chamber and positioning the spark plug on the top of the combustion chamber has improved the combustion efficiency.
• There are two intake valves and two exhaust valves per cylinder for a total of four valves and the intake/exhaust type has been changed to a cross-flow type, improving intake and exhaust efficiency.
• High pressurization is achieved by optimizing the intake port shape, improving the tumble ratio, increasing the combustion speed, and suppressing knocking.
• With the adoption of plastic region tightening * for the cylinder head bolts, axial force has been stabilized.
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*:Plastic region tightening is a method of controlling the tightening using the rotation angle of a bolt and suppressing the variations in the axial force by tightening the bolt until its deformation does not return to its original condition (plastic region).