Lightweight 8MM Valve
The smaller stem gives a slight boost in airflow but its main benefit is lighter weight which helps to reduce valve control problems commonly referred to as valve float in the most severe cases. This loss of valve control at high RPM can easily cost you 30 - 40 horsepower or more in severe cases. Not only is power reduced dramatically but reliability also becomes a concern as severe valve float can place un-do stress on the retainers, locks and valves. AFR’s 8mm valves are 15% lighter than our competitors 11/32 diameter valves which substantially reduces valve float. Valve float (or any loss of valve train control) is probably responsible for more mechanical engine failures than any other culprit. Dropped valves cause extensive engine damage! Big block Chevy heads are equipped with lighter weight 11/32 valves for all the same reasons. It’s our opinion that with the larger BBC valves, a move to 5/16 or 8mm would create reliability concerns with the head diameter and overall weight versus stem diameter. For those looking for the utmost in BBC valve control we offer titanium valves which are a fraction of the weight of their steel counter parts.