Radium Rotary Engine Injector Seat (Single) - Mazda RX-7 FD/Cosmo JC (13B/20B) M081 This ARP head stud kit

This ARP head stud kit uses premium grade 8740 chrome molly

then CLICK HERE for our 'custom' Mechanical Fuel Pump kit listing

So to seal the lower section to the upper we designed a dual stepped recess with the internal step protruding further down following the gas flow

Mitsubishi EVO VIII

Saab 93 1999-current

Radium Rotary Engine Injector Seat (Single) - Mazda RX-7 FD/Cosmo JC (13B/20B) M081 This ARP head stud kitThese are the same machined aluminum injector seats used in Radium fuel rails for Mazda Eunos Cosmo and RX 7 rotary engines. They are required when converting the OEM 16mm injector seat's counterbore to 14mm which is more common with popular injector lower O rings. They simply "pop" into the OEM injectors bore. They were designed specifically to be compatible with or without the OEM fuel injector diffusers installed. They seal to the machined injector