Comments by "geemy" (@geemy9675) on "Let's Settle This. Bore vs Stroke - It's Not That Simple" video.

  1. I think it's a bit more complex. increasing the stroke will not increase torque or power proportionally. it would be the case only if force of the piston was constant and independent from the parameters of the engine but all parameters of an engine do matter. -increasing stroke at identical rpm increases the speed of the piston, posing the same issues as high rpms: the combustion will eventually become too slow for the flame front to reach the piston and and, effectively reducing pressure into the piston/force. also higher acceleration/more force on the means more vibrations + more friction losses and longer stroke means more heat loss through the cylinder walls. also the absolute torque value of an engine is not really important, what is. important is maximum power, powerband width compared to max rpm, and overall power/torque curves shape. regarding performance, for similar displacement and boost, the engine with shorter stroke and higher rpms will always be more powerful. the engine with ~ square bore/stroke will have better efficiency because of reduced cylinder surface/volume and best compromise of efficiency/power/powerband
    1