quote:Originally posted by No Quarter:quote:the power valve is open until the vacuum reaches in this example 18"
Chris, sorry to say, but that's not correct, then the PV is hardened beyond use...
The power valve is designed to supliment the main jets when the vacume is lost on acceleration, when the engine is at idle the power valve is not open as the vacume at idle keeps it closed, when the engine is accelerated the following thing take affect in the carb, 1 the accelerator pump depresses the diaphragm in the pump and through the squarters delivers a shot of fuel above or at the boosters, number2 and at the same time the power valve opens and also provides additional fuel, as you reach a cruising speed and you engine rpm decrease the vacume returns and the power valve is closed, now the engine will run on just the jets.This is repeated every time you accelerate. When I referred to the 18 pounds of vacume in the article I was trying to illustrate that my engine that only develops 13 inches of vacume would never actuate the valve it would be open continually. By the way a 6.5 power vale would be for 13 inches of vacume , 6.5 X 2 = 13 .