The control apparatus operates an engine water temperature adjustment apparatus so that the temperature of cooling water that passes through an engine head enters a first temperature region in a lean mode, and operates the engine water temperature adjustment apparatus so that the temperature of the cooling water enters a second temperature region that is lower than the first temperature region in a stoichiometric mode. When knocking is detected after switching is started from the lean mode to the stoichiometric mode, the control apparatus performs any one of a first operation to operate a variable valve apparatus so as to retard the closing timing of an intake valve, a second operation to operate an oil jet apparatus so as to increase an oil jet amount, and a third operation to operate an EGR apparatus so as to increase an EGR amount.

The control apparatus operates an engine water temperature adjustment apparatus so that the temperature of cooling water that passes through an engine head enters a first temperature region in a lean mode, and operates the engine water temperature adjustment apparatus so that the temperature of the cooling water enters a second temperature region that is lower than the first temperature region in a stoichiometric mode. When knocking is detected after switching is started from the lean mode to the stoichiometric mode, the control apparatus performs any one of a first operation to operate a variable valve apparatus so as to retard the closing timing of an intake valve, a second operation to operate an oil jet apparatus so as to increase an oil jet amount, and a third operation to operate an EGR apparatus so as to increase an EGR amount.

A rocker arm assembly can comprise a main rocker, an auxiliary rocker, and a lost motion spring mounted to press on the main rocker and the auxiliary rocker. The main rocker can comprise a main body surrounding a main rocker bore, a valve end, a main cam end, and a main latch bore between the valve end and the main cam end. The auxiliary rocker can comprise an auxiliary body that is forked. A first auxiliary rocker bore and a second auxiliary rocker bore can flank the main rocker bore. A first auxiliary cam end and a second auxiliary cam end can flank the main cam end. A first auxiliary latch bore and a second auxiliary latch bore can flank the main latch bore. The lost motion spring can span over the main latch bore.

A valve train system that eliminates the inefficiencies of current spring biased systems. The system uses teeter beams that are manipulated by cams that are driven by cam shafts to control and operate the valve system more efficiently and dependably.

A valve train system that eliminates the inefficiencies of current spring biased systems. The system uses teeter beams that are manipulated by cams that are driven by cam shafts to control and operate the valve system more efficiently and dependably.

Provided is a copper-base alloy with excellent wear resistance. The wear-resistant copper-base alloy includes, by mass %: 5.0 to 30.0% nickel; 0.5 to 5.0% silicon; 3.0 to 20.0% iron; less than 1.0% chromium; less than or equal to 5.0% niobium; less than or equal to 2.5% carbon; 3.0 to 20.0% of at least one element selected from the group consisting of molybdenum, tungsten, and vanadium; 0.5 to 5.0% manganese and/or 0.5 to 5.0% tin; balance copper; and inevitable impurities, and has a matrix and hard particles dispersed in the matrix, when niobium is contained, the hard particles contain niobium carbide and at least one compound selected from the group consisting of NbCMo, NbCW, and NbCV around the niobium carbide, and when niobium is not contained, the hard particles contain at least one compound selected from the group consisting of molybdenum carbide, tungsten carbide, and vanadium carbide.

Provided is a copper-base alloy with excellent wear resistance. The wear-resistant copper-base alloy includes, by mass %: 5.0 to 30.0% nickel; 0.5 to 5.0% silicon; 3.0 to 20.0% iron; less than 1.0% chromium; less than or equal to 5.0% niobium; less than or equal to 2.5% carbon; 3.0 to 20.0% of at least one element selected from the group consisting of molybdenum, tungsten, and vanadium; 0.5 to 5.0% manganese and/or 0.5 to 5.0% tin; balance copper; and inevitable impurities, and has a matrix and hard particles dispersed in the matrix, when niobium is contained, the hard particles contain niobium carbide and at least one compound selected from the group consisting of NbCMo, NbCW, and NbCV around the niobium carbide, and when niobium is not contained, the hard particles contain at least one compound selected from the group consisting of molybdenum carbide, tungsten carbide, and vanadium carbide.

A continuous variable valve timing apparatus may include a camshaft, a cam device on which a cam is formed respectively and of which the camshaft is inserted thereto, wherein a relative phase angle with respect to the camshaft is variable, an inside bracket configured to transmit rotation of the camshaft to the cam device, a lifter in which the inside bracket is rotatably inserted therein and on which a cylinder opening and a shaft opening are formed thereon, a control shaft parallel to the camshaft and to which a control rod, inserted into the shaft opening, is eccentrically formed, a control cylinder on which a control rod opening where the control rod is inserted therein is formed and inserted into the cylinder opening, a guide portion guiding movement of the lifter and a controller selectively rotating the control shaft, wherein the lifter may move.

An engine power unit includes a crankcase, a cylinder body, and a cylinder head sequentially stacked and fastened with each other. A cam shaft holder is fastened to the cylinder head to rotatably support a cam shaft of an engine valve operating mechanism. A cylinder head cover covers the cylinder head and the cam shaft holder. Fastening bolts penetrate the cylinder head cover and the cam shaft holder to be screwed into the cylinder head. Pressing surfaces are formed on the inner surface of the cylinder head cover. The pressing surfaces are abutted against and press the cam shaft holder to the cylinder head. Thus, rigidity around the cylinder head is enhanced, and a weight reduction of the power unit is achieved.

An engine power unit includes a crankcase, a cylinder body, and a cylinder head sequentially stacked and fastened with each other. A cam shaft holder is fastened to the cylinder head to rotatably support a cam shaft of an engine valve operating mechanism. A cylinder head cover covers the cylinder head and the cam shaft holder. Fastening bolts penetrate the cylinder head cover and the cam shaft holder to be screwed into the cylinder head. Pressing surfaces are formed on the inner surface of the cylinder head cover. The pressing surfaces are abutted against and press the cam shaft holder to the cylinder head. Thus, rigidity around the cylinder head is enhanced, and a weight reduction of the power unit is achieved.