Power by Design
Factory Ford small-block heads have always been limited by small intake and exhaust ports, which limit flow, exhaust scavenging, and power. RHS decided to aggressively go after these shortcomings with its own fresh approach to the small-block Ford head. This approach came from down under at SPL in New Zealand.
The Pro Action cylinder head yields flow numbers that promise significant improvements in performance depending on how you build your engine. Figure in greater exhaust port volume, which helps scavenging. When scavenging improves, flow through the head improves dramatically. Intake runner volumes are 180, 200, and 215 cc, respectively, which give you three intake volumes from which to choose. The size you select depends on how you intend to use the engine. The 180 and 200ci intake runner sizes are more appropriate for street and strip use. A larger 215cc runner makes more sense for a stroker engine or for all-out racing because velocity comes on strong at high revs where racing engines live. Smaller runner volumes provide velocity (and torque) at lower rpm ranges, which make them more appropriate for the street and occasional racing.
Impressive flow numbers come from not just from runner volume, but how these runners manage airflow. Pro Action runner design eliminates turbulence, which makes the most of airflow. Improved airflow also comes from the way RHS radiuses the valve faces and seats.
RHS cylinder heads are unlike anything else you've seen because the Comp Performance Group started with a clean sheet of paper-and Clean Cast Technology. The unique RHS vertically integrated manufacturing process allows engineers to follow and control every detail of cylinder-head production. They follow the process from CNC-design to assembly, ensuring the best quality from a high-performance cylinder head. What's more, RHS does it all in one facility. Heads are designed, cast, machined, and assembled in the same location. This is an industry exclusive.
RHS management and engineers wanted a production cylinder head that was over the top with improved water jacket restriction to eliminate hot spots and detonation. They also paid special attention to intake and exhaust runners, bowl design, valveguide interference, valve design, and a host of other areas to make the RHS head a casting you could literally bolt on right out of the box without modifications. This comes from better CNC technology, which yields matched components you don't have to worry about when you're building an engine. Call it Power by Design.
Not only are the valve seats...
Not only are the valve seats and bowls designed for better flow, so are the valves. Even though these heads flow quite well out of the box, they can be fine-tuned with additional port and bowl work if you desire. Valve shrouding is minimal, which makes the most of chamber design. Multi-angle valve seats and radius exhaust valves outflow other heads up to 5 percent.
Cutting the casting in half...
Cutting the casting in half this way, you can see the unobtrusive intake port design. There are fewer angles, which means improved flow.
This cross section demonstrates...
This cross section demonstrates why these heads offer greater bang for the buck. Notice the roof and the smooth radius, which improves velocity and torque. Valveguides are recessed, which keeps them out of the way. The water jackets are designed to reduce detonation and increase thermal conductivity. Also note the thick fire deck for increased sealing for boosted applications and allowing angle milling as well.