Originally posted by SW_Radial:
... how do ya know if ya blew the power valve on onna them ?
Holley 600
Seriously, the most prominent sign of a blown power valve will be very bad performance. Like chugging, hesitating, bucking... Real hard to drive. If the carb is off the engine -- I'm most familiar with the 4160 4 BBl -- disassemble the metering block from the float bowl on one side. Extract the power valve from the metering block, Inspect the rubber diaphragm skin: if the skin looks popped, bubbled, or distorted, it's shot. If the diaphragm rubber looks smooth and tight (and has no holes) it's probably good. Some old school hot rod parts shop might still have power valve testers. Or maybe old hands who'll eyeball the power valve for you.
