Originally Posted by supershaft
I have already tried to explain that many times on this forum. Yunick can do it better than I can. In a nut shell, it changes TDC (and BTC) piston dwell. Longer rods increase TDC piston dwell. The piston hangs around TDC longer for the flame front so you can light it later. I have helped set up and dyno tune long rod beemers.
Could you be more specific?