Internal combustion engine camshaft and internal combustion engine

The internal combustion engine comprises a wheel shaft assembly, a first mark, a second mark and a third mark, the wheel shaft assembly comprises a bearing cover and a shaft body, the bearing cover and the shaft body are rotationally connected, the first mark is arranged on the bearing cover, the second mark is arranged on the shaft body, and when the first mark and the second mark coincide in the axial direction of the shaft body, the third mark is arranged on the shaft body. A first air cylinder arranged on the internal combustion engine is located at a compression top dead center position, a third mark and a second mark are arranged on the bearing cover in the radial direction, and when the first mark and the third mark coincide in the axial direction of the shaft body, the first air cylinder is located at an exhaust top dead center position. According to the timing mark observation device, an operator can directly observe from the outside, it is guaranteed that the timing mark can be observed, the observa