kweng : ping / knock may occur out of lean afr (precombustion because lean mixture combustion emits large quantity of heat, too much and ur internals may melt), and overadvance ignition timing. just imagine dis, combustion compressed mixture of air and fuel gives out a lot of energy and heat. if u overadvance (keyword : overadvance, hence advancing is safe, as long as its witin the safety limit. outta the limit, and u r OVERadvancing the ignition limit) the ignition timing, the mixture may pre-ignite and combust before the actual power stroke is supposed to be at, BUT the piston is on the way up and wit the combustion process advanced too much, it is force to go down. wit two forces applied to the piston (dynamic way up, combustiom forces it to go downwards), it cant go nowhere but force its way up, since the other pistons and crankshaft assembly is forcing dis particular piston up. dis piston will rattle on its way to balance the forces applied to it, hence u have a vibrating piston, bearing, internals which may score ur block, fark ur bearings, etc.
BUT, just imagine.. if u combust a compressed mixture and creates a whole lot of energy, how much energy can u create if u compress a combusted mixture? u get me? d 2nd process will emit even higher energy and will push the pistons down faster then the first process, which will give u higher torque output.
p/s otai2 :sumone please correct me, i think sumthing r wrong in my post ler. iam too pening to re-check, sorry ya..
BUT, just imagine.. if u combust a compressed mixture and creates a whole lot of energy, how much energy can u create if u compress a combusted mixture? u get me? d 2nd process will emit even higher energy and will push the pistons down faster then the first process, which will give u higher torque output.
p/s otai2 :sumone please correct me, i think sumthing r wrong in my post ler. iam too pening to re-check, sorry ya..