Some of the early spray-oiler engines, 216s and I believe 235s, had an umbrella-shaped sheet metal cap that fit over the top of the valve stem and the spring retainer. I've seen them on late 1940s engines.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!