[x-bird]

I was thinking along those same lines--exhaust or stovepipe style dump valve in the middle of the blower tube. i have an old pontiac choke valve still in a log manifold that would do the trick nicely--isn't too rusty either, which is pretty rare for that piece. the entire run, no matter what rate it's set at would have to be sealed--as soon as it's got a port in the tract to atmospheric pressure, it isn't going to work nearly as well if at all. Definitely would have to add a tach. I have a "standard" 4-bolt gy6 or the sym engine. since i can't get decent valve springs/cam for the sym, i may do this with the 4-bolt engine, which is just gathering dust. stick some spacers under the jug to cut the compression ratio, cam and carb are really the two items that make this difficult. Still think one could build a really screamer doing this. Plenty of you tube vids of people sticking leaf blowers in their car intakes on the dyno and getting significant gains without changing anything. of course nearly everyone of them killed the engine because of valvetrain/rev issues and inadequate fuel.