Thermal insulated intake ports

In a spark ignition reciprocating internal combustion engine for use with gasoline fuels said engine having an intake port area extending between an intake manifold and an intake valve, said valve disrupting flow of a fuel air mixture into a combustion chamber;

• the improvement which comprises having a substantial portion of the surface of said intake port area coated with a thermal insulating material for reducing transfer of heat to the fuel/air mixture which traverses said intake port area during operation of said engine, said insulating material consisting essentially of one of the group of polyphenylene sulfide alone and polyphenylene sulfide in combination with synthetic resinous polymeric materials having in their chemical structure at least one element selected from fluorine and silicon.