When the piston is at TDC there is a few degree of free play on connecting rod and crankshaft before piston starts to move down. Are you consider that free play as part of TDC or not.
For example, when piston is all the way up, it will take for example 2 or 3 degree of conterclock wise before piston starts to move down.

so TDC consider + the extra 3 degree of the free play or - the extra 3 degree?

Thanks
Borna