A manufacturing method for an engine includes: preparing, as a preparing step, a cylinder head having a surface on which a ceiling surface of a combustion chamber is formed; forming, as a film formation step, a thermal insulation film on the ceiling surface; measuring, as a measurement step, a volume of the thermal insulation film; and selecting, as a selection step, a rank for an engine valve to be used in combination with the ceiling surface so as to correspond to an amount of difference of a measured volume of the thermal insulation film from a designed value of a volume of the thermal insulation film, the rank being selected from a plurality of ranks set in correspondence with thicknesses of umbrella portions of engine valves.