Valve seat change that?s taken place

Posted by zjautopartsLee on February 17th, 2016

Many of the Carburetor float, high output diesel engines today are running steel pistons rather than aluminum pistons. This means a catastrophic valve seat failure can cause a lot more damage inside the engine. So the last thing you want is a seat alloy that’s prone to cracking.

Though powder metal seats are used in most late model passenger car and light truck engines with aluminum cylinders, powder metal seats are not used in most heavy-duty diesel engines. Why? Because the type of powder metal seats that perform well in automotive engines generally don’t do well in a heavy-duty diesel environment.

 That’s why heavy-duty diesel OEMs typically use stellite, chromium, cobalt or nickel alloy seats, or the new proprietary cast iron high heat alloys that have been developed for these engines.

Valve seat change that’s taken place in the heavy-duty market is that many OEMs have stopped selling replacement valve seats because they want to sell complete cylinder heads. Others only offer replacement seats in standard sizes (which is good for aftermarket valve seat suppliers provided they have oversized replacement seats in the right alloys for the application).