Big Valve Military head?

[Robert_Wilkinson]

@PeterCrespin

The key valve gear difference is a mechanism to ensure continuous slow but positive rotation of valves.

I vaguely recalled discussing this before, and tried out our spiffy search feature:

[E-Type] XK cylinder head: Rotating valves?

All, I wonder if the valves do actually rotate when the engine runs ? In my case the shafts were all badly worn on one side of the motor, so I think they actually do NOT rotate and thus wear faster then must-be. The valve stems only have one groove, and the small retainers were all stuck, at least one of every pair was so frozen I had to use a small hammer to whacken them out of the valve collar. Is this normal ? Where later XK engines improved on this issue ? Mine is 1966 4.2. And,…