An exhaust manifold is covered by a manifold heat shield cover and an exhaust pipe is directed downward from the exhaust manifold. In such an engine, a cooling fan is disposed on a front portion of the engine and the exhaust pipe is positioned on the air flow path of the cooling fan. An auxiliary component heat shielding plate is directed from the manifold heat shield cover along a back side of the exhaust pipe. An auxiliary engine component is disposed beneath the manifold heat shield cover on a back side of the auxiliary component heat shielding plate. Between the exhaust pipe and a cylinder block, an air flow guide plate provides an air flow space between the air flow guide plate and the cylinder block. A cooling air flow passing through the air flow space is thus supplied to the auxiliary engine component.