mtngun again I a agree with you, you have way more experience and knowledge than I.
No, I'm strictly a newbie at the saw modding game, and have never raced, and probably never will. You've been playing with saws far longer than me.
My query is, in a good running saw, does 10-20+ pounds of compression really give you much?
I can tell a difference on my milling saw. I can even tell a difference in how the saw runs on a cold day, when the air is denser, vs. a hot day. Compression gives it more grunt, it doesn't bog as easily, and it's easier to operate.
Anyone who has ever cut wood at high elevation, where the saw loses compression and power, has noticed a difference.
Whether a cookie cutter would see a difference in times, I don't know, perhaps depending on the diameter of the cookie. I give Brad credit for using big rounds in his tests, so the saws have to work hard.
There are compromises with any mod. A pop-up, or merely tightening the squish, increases intake duration, which may actually hurt the low end. Without a dyno, or at least a good computer model, we're just fumbling around in the dark.
However, TW does have a dyno, and he does have computer models. That's why I posted his power curve for the 460. Unlike me, TW is in a position to say whether a particular mod helps. If a pop-up didn't help, I don't think TW would do it. And what he has said about the 066/660 is that, in the old days, all you had to do was drop the squish, but with the new jugs, a pop-up is the way to go.
158 psi doesn't sound so bad, but that would only blow 135 psi where I cut.
If it were my 660, I would absolutely do a pop-up to get the compression back up.
opcorn:
