At 02:59 PM 6/27/02 -0600, David Councill wrote:
>"Stellite exhaust valves - what are they exactly? They are almost twice the cost of a regular exhaust valve ...."

They are hard coated stainless steel exhaust valves, and I mean VERY HARD COATED (mince no words). Anyone who drives a lot of miles or runs an engine hard should want these things, as they are worth every penny of the price. If you believe me and that's all you wanted to know you can skip the rest of this message.

I put a lot of miles on my MGA, lots of cruising in the fast lane on the expressways, a moderate amount of very serious autocrossing, and more light trailer towing than all other mileage combined. I used to wear out a set of stainless steel exhaust valves every 40,000 miles or so until I started using Stellite exhaust valves. Now I can run an engine 100,000 miles and the valves are still in nice serviceable condition, even though the rest of the engine may have taken a beating by that time. The combination of hardened steel valve seats, Stellite exhaust valves and bronze valve guides is a real winner (giving the bronze guides a skosh extra running clearance for thermal expansion). My last 100,000 mile cylinder head was transferred to another newly rebuilt engine after only minor touch up of the land width on the hardened steel exhaust seats. I have to date never managed to wear out a Stellite exhaust valve, although I do prefer to install new ones when I do a general engine rebuild after 100,000 to 125,000 miles.

"Deloro Stellite" is a manufacturing company with facilities in several countries around the world. They manufacture intricate castings, compressed powdered metal parts, and machine parts. They supply materials and alloys to other manufacturers. And the make machinery for hard facing, machining and laser cutting. Most of their business is related to high temperature, high wear and high corrosion applications. They sell and/or license hard coating equipment to other manufacturing companies.

In context of that last sentence, "Stellite" is a company name (Deloro Stellite), and a trade mark or trade name, and also a process name. The name has become generic in the sense that people sometimes refer to any hard coated part as a Stellite part, but I'm sure they still enforce their trade name, so other manufacturers are not allowed to use the name "Stellite" except under license agreement. Various hard coating equipment that they manufacture and sell is referred to as Stellite coating machinery. The parts treated with this equipment may be referred to as Stellite parts (as in Stellite exhaust valves). A different company who buys the Stellite equipment and uses it to manufacture hard coated exhaust valves and also buys license to the name might legally call their parts Stellite exhaust valves. As such these Stellite exhaust valves may or may not be manufactured by Deloro Stellite, but you may trust that the hard coating is pretty much the same wherever they originate. You may trust the name. It's a hard world.

Barney Gaylord
1958 MGA with an attitude (and lots of durability)