The fine folks over at Engine Pro — suppliers to engine builders and machine shops exclusively — have developed their line of engine valves for serious applications. In this video, Dave from Engine Pro discusses the important features the company’s Nitro Black valves use to ensure longevity and stability when pushed to the limit.
But first, he explains that the company’s 2000-series valve offers all of the traditional performance features; swirl polished valve head, hard chrome stems, friction-welded tips, and is forged from high-strength 21-4N stainless steel.
The Nitro Black valves are the ones we found most interesting. They have all of the features of the 2000-series valve, but add the company’s proprietary liquid nitriding process to boost durability and longevity in performance applications.
The Nitro Black valve is not coated; rather, it’s been subjected to metalligical changes to make the end product more robust.
Although the Nitro Black process is somewhat secretive, Dave expands upon the different stages of a Nitro Black valve’s creation. High-heat treatment, a cooling session, and then more heat and other steps to the process including the formation of magnetite over its entire surface, which helps the valve to be 21-percent smoother than a comparable chrome valve.
Perhaps most importantly, the Nitro Black process runs much deeper than the surface, giving the valve the ability to bend rather than break in the instance that it is contacted by the piston. Less breakage means less expensive carnage if you’re pushing your engine to the limit. He goes into greater detail about the process in the video, so make sure you check it out. They don’t show every step of the way — some things remain proprietary — but he’s rather forthcoming about what happens to the valves during the manufacturing process, and how they end up with the characteristics they have.