Engine torquing over = knock on shifts?

[Toady]

I didn't want to hijack SS/GN's thread on the RJC engine brace, so I'm starting a new thread.
http://www.turbobuick.com/forums/general-turbo-buick-tech/299855-rjc-new-engine-grace.html

In the videos showing how much the engine rocks, I was shocked at just how much deflection there was. When people experience "knock on the shifts" - myself included - is this what's happening? And what exactly is happening - stuff hitting the frame as the engine rotates, or the knock sensor going off from the actual movement, or something else entirely?

Just wondering out loud,

 

[TurboDave]

It's always possible that's the source but not always likely.

Knock on shifts, particularly the 2-3 shift is most often a result of the load produced at that point. If your tune in on the edge, the added load produced at that shift is usually enough to produce dentonation.

 

[Toady]

Thanks, Dave. I was going on the assumption that knock on the shifts would typically be false...never thought about it having a real cause like that.