There are many graphic illustrations of piston motion on the internet, usually with explanations showing some calculus.

There are three piston events that are still not widely understood, however.

When the piston leaves TDC going down, these 3 things ALWAYS occur IN THIS ORDER:

1.) peak piston velocity, when the rod and crank are at a right angle. Crank degrees depends on rod ratio.

2.) The piston is halfway down the bore.This happens before the crank has turned 90-degrees. Crank degrees depends on rod ratio.

3.) the crank has turned 90-degrees. Piston is now more than halfway down the bore. You guessed it, how far down depends on rod ratio.

This is not a matter of opinion, it's a matter of fact. I hope this helps folks.

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If the connecting rod was infinitely long, the piston motion would be a perfect sine curve, and all the math would be very easy.
Any rod length less than infinity and the sine curve is "modified", but it's still not that complicated.
Yes, you could say the differences are subtle. "Subtle" is subjective.