What is Quench

Wyrmrider said
On the Quench domes- were they not some of the ones that shrouded the spark plugs on BBC, Cleveland etc

Yes, I know first hand for the 351C quench domes. Those ones I had (still have) had fire slots cast in; you know how that works: it became a 'feature'. Boy, I am glad someone remembers these! I was getting paranoid LOL