Device for adjusting valve duration using external air supply

A device for adjusting engine valve duration using an external air supply, comprising:

• an exhaust manifold;
• a heat protector disposed over said exhaust manifold for forming a manifold space, said heat protector having a tubular port disposed at one side thereof;
• and
• a cylinder head disposed in the vicinity of said exhaust manifold, said cylinder head including:
• an air ventilating passage for ventilating heated air generated from the manifold space,
• an operating chamber, operatively communicating with said air ventilating passage, and communicating with an oil circulating passage, said operating chamber containing a piston with a bore disposed perpendicular to an axial direction of piston displacement and a spring for biasing the piston,
• an inner spring seat seated thereon,
• an outer spring seat disposed over said inner spring seat for forming an air passage space communicating with the air ventilating passage and a pair of corner spaces for storing an annular wax insert,
• a valve having a movable valve stem passing through said inner and outer valve spring seats and fixed to a retainer, and
• a valve spring seated on an annular rim portion of said outer valve spring seat at the bottom thereof and attached to said retainer at the top thereof,
• such that when engine oil has high pressure at a high vehicle engine speed the bore of said piston communicates with the air ventilating passage by upward movement of the piston, the heated air expands the wax insert and the wax insert compresses the valve spring, so as to adjust the valve duration and effectively improve output power of the vehicle engine.