Originally Posted by
Roelof
I have seen a video about Cosworth engines where the engineers did calculate the zero headclearance at max rpm and indeed you could see a complete clear squish band on the piston. Flex is there and it is needed to stay alive. I just calculated it, at 44.000rpm the (lineair) acceleration of the piston in an half stroke a 3 gram piston can create about 30kg of force. With the conrod making 5 to 6 grams in total it can go up to 50kg, that is huge! It is for sure pushing and pulling hard on the crankshaft,
You need to upload them....
I understand what you are saying but that movement is not soley from the crank but more from the other moving parts. The crank is only one part of the equation and since the crank is the hardest and most unlikley part to actually "flex" the movement you see is from the soft piston deflecting,rod deflecting, dual bushings and wrist pin all of which will move/flex more than a crank. Why would the actual crank flex before any of the other moving soft parts? I want to bring up the fact that movement and flex are two completely different things. A resonance can and will cause flex where as movement is just simply from tolerances on moving parts. I am a little confused on which one you are attempting to explain!!