We have been using Supertech valves in our race program for many years. We even use them in our Endurance Engines for the 25 Hours of Thunderhill and they performed flawlessly. We believe they are some of the Best on the market at any price.
Supertech Valves are manufactured using the highest quality materials available. Intake valves are manufactured exclusivly from and enhanced version of EV8(21-4N) Steel. This is the highest grade of Steel available and provides the strenght to withstand just about any application. The exhaust valves are manufactured from EV18(21-8N) or EV8Nb/w for greater strenght at higher temperatures. For Engines producing 120+ HP per liter or Supercharged/Turbo we recommend valves manufactured from Inconel 751/Nimonic 80A. These valves will withstand even the highest of combustion temperatures.
About Supertech Racing Valves
Production of Supertech racing valves begins with a one piece forging, where the head of the valve is forged under a slow two step process to keep a good material grain flow. The forging is then CNC machined in several steps to ensure the precision of the final dimensions. Then they go through another heat treatment for stress relieving followed by a nitride hardening treatment (or coating process depending on the application). Lastly, one more grinding, followed by Supertech's patented Superfinishing of the surface to ensure that each valve is free of any imperfections and the dimensions are precise.
Great kit and customer service 
