Originally posted by thesals
the goal really is to get combustion to happen before the piston starts traveling down but after the rod has changed sides on the crank journal, that way when the combustion happens, there is the least amount of resistance.... if we have it directly at true TDC then it would push directly down on your crank, if its btdc it'll push the crank the wrong way
Hi thesals;

You might want to re-think the “included quoted part” of what you said. Cranking timing or idle timing, is set anywhere from 4-12 degrees, BEFORE top dead centre. Once the engine is running and gets off of idle, the timing keeps advancing to as high as 40 degrees btdc. In this way it creates compression and gives it it’s horse power and throttle response.