[. All I know is that the power valve is not supposed to be open at idle, but probably is, since it's pulling 7-inches with an 8.5 PV...[/quote] Exactly,the idle will probably sharpen up a bit with a lower number P.V in it.
Yeah, the two 4160s I previously had came with 6.5s, but these Street Avenger carbs come with an 8.5, which was perfect for the old engine. I have the same 3.55 gears that I had before, and I am instantly at 2000 RPM (the cam is rated from 1500-5500). I just hope I can wake it up with some tuning and getting some miles on it. Otherwise, I may have pony up for some 3-inch pipes on it...:evilsmile
The power valve richens the main circuts only. As long as its not leaking it will not affect idle. On my car i use the cruise method for picking the power valve, get on the highway at cruise speed and hold steady note vaccum, pick 2 to 3 numbers lower than cruise vaccum.
That is correct, it only richens the fuel that comes out the boosters, not the idle circut. UNLESS its leaking.
The power valve feeds the main well through the power valve channel restrictions. The main well feeds fuel to the idle, transfer slot and the emulsifier tubes that feed the venturi fuel. It is possible for the power valve to upset the idle mixture if the carburetor throttle plate is open far enough to pull fuel from the transfer slot. Paul
Hmm....so maybe I changed it for nothing. I installed a 4.5 yesterday, and there wasn't much difference...
