Dennis- your research is sound to me. The Husky 242 ( or was it the 246?? ) was marketed under the same guidelines and almost always performed better when ported and tuned down to 13,5.
Russ- one thing to remember- When a builder raises the ports in a cylinder, and lowers the overall cylinder to increase compression, yes, they are raising the powerband, that is the RPM range in which the powerband operates best, but they're also narrowing the same powerband. You can get away more rpms because you're increasing the amount of fuel and oil reaching the compression band before compression, but higher top RPMS don't necessarily mean faster cutting in a working saw- because when you raise the power band you raise and change the duration of the torque band also- when putting the saw under a load, the torque band is eventually what determines how fast you cut overall, in a working saw.
I'm currently running a highly modified Stihl 440 in the woods- I've raised the peak RPM to 14,500- the sweet spot is still 9,000 rpm- regardless of where the peak RPM range is. 9,000 is where the powerband has kicked in and I'm getting maximum bang for each stroke. The saw has been highly, highly ported- including the piston, the crown of the piston was shaved and shaped with a small dome- the cylinder lowered to increase compression.
From what I've witnessed, a race saw is basically brute force- A machine pushed to the absolute max because the cutting duration is only a few seconds. A working saw relies on the finess of the design- efficiency + a good powerband = best overall cutting.
When power porting a stock saw, a builder is merely enhancing the basic design. It's only when you get into adding transfer ports, making custom pistons, making custom cranks- then you're redesigning the saw.
