Re: 1954 359 L8 / Iridium spark plug in place of Autolite copper resistor 308 spark plug

Posted by Tim Cole On 2022/3/28 15:11:43

Hotter plugs are applied to prevent fouling due to service like short trip usage, worn rings, overly rich mixtures, and so on. I had an old BSA motorcycle that fouled the standard plug because the capacitance discharge ignition was weak. I used a hot long reach plug and the thing always ran afterward. I got more cheers on that BSA than any Packard I ever drove.

Cooler plugs are used for high speed driving. Given the Reinhardt styled Packards have significantly downsized radiators they already run hot.

As well, isn't that Slick 50 stuff some kind of graphite thing? Somebody told me that Harley-Davidson used that stuff.

Right now I'm dealing with somebody who was involved in NASCAAR, I'll try to remember to ask him what he thinks of graphite in engines.