On such interesting discussions, a little hijacking is not a bother!

In some ways, this is somwhat like the behavior of RF in a waveguide, or the tuning of a musical instrument. If the inherent resonances focus at a certain undesirable point. The output is altered in amplitude or frequency in any one of a number of undesirable ways. In this case when the pulse or wave movement has enough force it can physically eject the fuel charge. Pretty fascinating to me!

Since you have, as I recall, a long straight section under your axle, can you use a telescoping section and tune it like trombone?

One of the larger header manufacturers marketed Anti-reversion headers for a short time some years ago. I saw some interesting testing on this in Tucson many years ago. In the end I think they were too labor intensive and fell out of the market. Sin of sins, they were Tri-Y too!

Just did a web search and much to my surprise, apparently this is a technique advocated by Paul Grimshaw in the "Volvo Performance Handbook". You are probably better versed than I on this, but here is the link regardless:

http://www3.bc.sympatico.ca/Volvo_Books/maint4.html

We will be watching! happy hunting!!

Mike