The LSK has a 6 bolt head like the Cobra, the Speed has a 4 bolt head like the Sport, Serpe and the RAL engines from a few years back. From memory the Speed had a integral combustion chamber with the heatsink..

I agree that the best looking buggy engine ever is the Black Magic, but the best engines Axe produced were the Gold Head 198 Cobra with a turbo button. A few years ago I think they were the equal of any engine available for buggies. Then the conrod issues started