Chainsaw Repair

.... torque is where its at, and always was, imo.

TQ= (HP x 5252)/ RPM

you moved the TQ peak up from the stock 7000 to 9000 range into the ported 7000 to 10500 range.  the extra 1500 rpm or so, move up the ladder did the trick for the HP gains shown on the graph.

the bmep thing, just shows the stock peak TQ compared to the ported peak TQ using cylinder pressure.  just find it easier for me to see the true gains this way.

HP graphs look nice, but imo, don't show the two most important measures of a motor.  acceleration time and rpm recovery time (when a motor has come off peak TQ rpm).

i'm just a guy who does not know much of anything when it comes to saws, but have an incurable interest in how/why motors work.  in my head, all my motors run on math.  hahaha.

-joe