Diesel performance continues to grow in popularity as enthusiasts add power to their tow vehicles and what they race on the track. With this progression in performance comes a need for stronger engine parts that require different upgrades than your typical gas engine. One area that has been the focus of improvement by companies like Engine Pro is the valves that live inside a diesel engine’s cylinder head.
The diesel engines we all know and love have the ability to become absolute torque monsters that can rotate the earth when you start modifying them. These mills can be fed levels of boost that would shatter a gas engine, but you still have to provide the supporting modifications to make this happen safely. Paying attention to the small details like the valvetrain allow a diesel engine to become a beast at towing or run well into the single digits at the track.
Ron McKey from Engine Pro explains some of the challenges a valve will experience in a high-performance diesel engine.
“The biggest problem for a diesel engine that makes big power is the exhaust valve. Because all modern diesel engines employ turbochargers they subject the exhaust valve to higher temperatures. The exhaust valve is prone to excessive heat and heat equals wear. Valves operating at excessive temperatures that are not made of the proper material will lose tensile strength and fail.”
Understanding the challenge of creating a valve that can deal with the intense environment created by a diesel engine Engine Pro used their 21-4n stainless steel material for their diesel intake valves. These valves are put through a five-step step nitriding process, the same one that’s used for their Race Series stainless valves.
The Engine Pro diesel exhaust valve is created using a more complex process since it faces a different set of conditions. McKey explains why Engine Pro constructs their valves from Inconel material.
“Inconel is used in jet engines where the intake temp can be as low as -70 degrees and the exhaust temperatures can be as high as 2,000 degrees. While typical diesel exhaust gas temperatures are in the 1250 degree range, a rich situation that produces black smoke results in much higher temperatures. We feel the use of this material provides an adequate cushion to prevent valve failure. Temperature extremes also accelerate oxidation. An exhaust valve can go from ambient temperatures below zero to over 1200 degrees very quickly and that stresses the material reducing strength.”
The final step in the exhaust valve manufacturing process is the addition of a satellite face by Engine Pro. The satellite alloys are a blend of nickel, iron, carbon magnesium, sulphur, silicon and titanium. This provides a wear-resistant material for the head of the valve that works well in high-performance applications.
If you’re trying to build a stout diesel engine make sure you head over to the Engine Pro website to learn more about their high-performance valve train parts.