I don't see how grooving the head to direct a richer fuel air mixture towards a spark plug applies to a commonrail injected turbodiesel engine but:
would creating a 'sweet spot' in the combustion chamber lead to more efficient fuel burn or just cause detonation problems? I would guess the latter. he seems more concerned with simply getting the cylinder to fire using the minimum required fuel and oxygen rather than compression ratio's and actually making power - I would guess his theory would have better practical application in engines measured in 10's of cc's rather than liters... I'm no mechanic, though, so I may be missing something obvious in his thinking.