Reply to thread

Message: [QUOTE="TARM, post: 317732, member: 578"] Thank you now this is what I am speaking of. I figured Dave as you have the ability to read cyl pressures and I am guessing seeing the actual pressure curve of the combustion event and you can also see where the crank angle is at during the various points in that cycle you would have good insight in to all of this. That is IF I can word what I am wanting to get across correctly so that you can actually answer them LOL Matt, That is exactly what I am getting at and what kind of got me thinking down this path. There is a difference between what I have seen called instant TQ versus average or mean torque. then looking at that along with where the piston is and how fast it moving would effect how concentrated the tq peak is focused on the piston and thus the rod. Pocket, I understand where you are coming from. That is where I started. Tq is tq is tq. But the more I read and thought about it the more it becomes apparent this is not the case. We measure TQ at a crank of an engine. But now consider what is going on at the individual cylinder,piston and rod. Lets assume tq may be consistant at the flywheel do you think that pressure against the individual piston is consistant as its being pushed downward as that fuel is combusting? Or do you think there is a point of peak force from the combustion pressure that is then ever decreasing as the piston is moving downward? Now consider that the time it takes for combustion to happen is relatively the same. But now change the speed the pistons are moving (higher or lower) RPM. Now think how that may change how long or much of that peak force is pushing on that piston. Also there only 1 powerstroke as RPMS go up or down the down time between that one power stroke changes. SO if you are going to have the same mean or average tq @ the flywheel at slower rpms that peak force is going to have to be greater to get that same mean tq. This is at least how I am seeing it based on the data I can find and engine diagrams and animation. [/QUOTE]