Manley “Pro Flo” Valves
The folks at Manley Performance have a long history of coming up with new ways to improve horsepower and reliability. One of their stellar achievements is the “Pro Flo”
valve design, which employs a specially undercut stem near the head to enhance flow.
Back in the 1980s, following the Pro Flo’s introduction, Hot Rod Magazine conducted a series of tests that documented the amount of improvement over OEM intake and exhaust valves in a 1969 Camaro. The Pro Flo intake demonstrated improvements up to 42% at lower valve lifts and the exhaust a stunning 93% gain. As the valves opened from .200” to .400” the differences grew tighter —but even at .400” lift the Pro Flo exhaust valve showed a 14% gain. You could liken it to a “bolt in” cylinder head porting” without the hassles.
In addition to the enhanced flow, an added benefit was a reduction in the valve’s weight, which can improve RPM potential as well as reduce wear on the valve seat, springs, etc.
Today, Manley Pro Flo valve designs are available in the Severe Duty series of stainless steel valves, the “Race Flo” for moderate competition and the economical “Street Flo” models; all have the same basic design, but are manufactured from different alloys. For details visit www.ManleyPerformance.com or call 732-905-3366.