by loucrane » Thu Jun 01, 2006 1:12 am
Walt,
Seems many modern engines have a modified 'squish band' head , which tapers from the cylinder wall a bit up toward the plug. This modifies the intention of a squish band, which is to allow ordinary compression until the piston is very near Top Dead Center, then - hence the word - 'squish' the unburnt fuel/air mixture into the smaller 'bowl' shaped combustion chamber.
A flat squish band - parallel to the piston face - squirts the fuel/air mix into the bowl with a lot of energy and swirl. Both help get it burnt in the least possible time, and help get the max of it burnt in that time.
A smaller 'band' (parallel to piston face), and some taper towards the glow plug, seems to 'soften' the hammer blow of combustion in a 'flat-squish and bowl' arrangement. That makes things nicer, less vibrating, and easier to set to do what you need done.