Regardless of the care in assembly and quality of your engine components, the most important steps toward high performance are found in the cylinder heads. Valve sizes, port shapes, and the combustion chamber profile can combined to work in perfect harmony with a specific camshaft and other factors.  This harmony yields an engine that produces usable horsepower, and extracts the maximum power from each drop of fuel.

They cylinder heads modified by Valley Head Service all share a common element: quality.  Leak-free valves or fresh paint are simply not enough. Each of the heads we sell is intended for a specific engine purpose, ranging from optimum fuel economy to purebred racing.

The most important operation is to insure the guide clearances are

Street Value Work

Valley Head Service street valve work fills the gap between repair shop valve grinds and racing work; we add the details that make the difference. The valve seats receive a three angle profile to optimize flow at intermediate throttle positions, and to improve throttle response in the street environment. Guides and valves are careful inspected for any defect prior to assembly, and afterward to verify that no spring or stem binding will occur. The result is a completely dependable and leak-free cylinder head.
 

Marathon Valve Work

Our intermediate valve and seat preparation is designed for mild competition or performance street use. To assure seat longevity, intake seats are held to 0.060", and exhaust seats to 0.080" on their contact faces.  Multiple angles for the remainder of the seat profile assure excellent mixture flow at a wide range of port airflows and velocities. Marathon valve work includes; lapping the valves to the seats to verify we have 100% contact between the valve seats and the valve. Setting all spring heights to your cam manufacturer's specifications, providing uniform seat pressure and maximum potential from your combination.
 

Hyper Flow Valve Work

Regardless of the airflow potential of either an intake or exhaust port, it can be lost in the transition between the port and the combustion chamber. Airflow between the seat and valve guides areas, and the transition from the seat into the chamber are crucial to making the overall package effective. We continuously investigate and verify mechanical advances in airflow techniques so that we can provide you with the best available valve and seat profiles. Valley Head Service's Hyper-Flow valve work is performed exclusively by our veteran airflow specialists. They combine the grinding wheel with their experience to form shapes that really work.  Cylinder heads with our Hyper-Flow valve work are hand shaped for the best airflow past the valve and perfect valve sealing. Naturally, Hyper-Flow valve work also includes precision-set spring heights to your specifications.