I nominate Peter for a trophy for a lucid explanation re spark plug differences. Jerry53 ----- Original Message ----- From: "Peter Engel" <peter.engel@xxxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Thursday, March 20, 2003 9:42 AM Subject: IML: Champion vs. Autolite -- "inside" info > So I'm reading posts from another list I'm on and I see the following > write-up. I'm convinced. Well actually I was convinced before reading > this. > > Ron Fenelon wrote: > > When I first started working at Ford in 1965, I was a "dyed in the wool" > Champion Spark Plug guy. A couple of years later, I had the opportunity > to visit the Fostoria, OH plant where we made Autolite spark plugs. > Once I saw the difference in the manufacturing process and the sealing > method vs. what Champion does, never again did I use anything but a > Autolite/Motorcraft spark plugs. On the GM cars that I have owned in > the past, I always used AC spark Plugs, because they were made the same > way as the Autolite/Motorcraft's were made. > > The principal difference is how the center electrode/porcelain insulator > is sealed to the steel outer body. In Champion plugs, the outer body is > zinc plated, and they stuff a powdered form of the center insulator > between the body and the fired center insulator, and then roll > over/crimp the upper portion of the steel body. Very easy to allow > combustion pressures/gases to make a leakage path in this powder > material. In fact, I asked TV Tommy Ivo, at the Milan, Mi Drag Way, why > he had changed from Champions to Autolites, in the early 70"s, and he > replied too many center electrode/porcelain bodies blowing right out of > the threaded bodies on his AA Fuel Hemi powered Dragster. > > The Autolite/Motorcrafts and AC plugs have two copper o-rings installed > between the center electrode/porcelain bodies, top and bottom, and then > the top of the body is rolled over/crimped, and then the plug passes > into an Induction Heater where the center portion of the plug is heated > up by a ring in the center of the steel body until it glows red, about > 1600 degress F, all while the crimp is held under 2500 psi pressure, and > then the Induction heater coil is turned off, and plug cools under this > 2500 psi pressure. So the center electrode assembly is firmly gripped > by the outer body, and I don't remember anyone saying they ever had any > leakage problems with plugs made that way. That heating process is the > reason Autolite/Motorcraft and AC plug metal bodies are not plated. > They may be painted, like the marine plugs are, but never plated. It > would boil off in the Induction Heating/Crimping process. > > Make better way to seal the center electrode assemblies, and make long > life spark plugs. > > >