30.93mm(1.218") exhaust valve for 8 port pre 2012 specification only this valve is longer than other A series varieties and plasma heat treated to eradicate wear from unleaded petrol. 98.35mm total length. 3.879 " The valves for the current 8 port heads from 2012 were made slightly longer than these where we increased height to bring in 21cc combustion chambers and cannot be used on earlier heads.