The Ford Barn - View Single Post - Y Block Normal Vacuum w/mild Perf. Street Cam?

Sid · 01-06-2020, 10:08 AM

The power valve is controlled by manifold vacuum. When manifold vacuum drops. When you mash on the gas pedal manifold vacuum drops and the power valve enriches with more fuel. If you have a high numbered p.v. enriching can happen too soon and even a rich idle on a modified engine and too low number can cause a hesitation. ( vacuum secondaries on a 4 brl are controlled by venturi vacuum.

01-06-2020, 10:08 AM	#17
Sid Senior Member Join Date: May 2010 Location: Rathdrum Idaho Posts: 737	Re: Y Block Normal Vacuum w/mild Perf. Street Cam? The power valve is controlled by manifold vacuum. When manifold vacuum drops. When you mash on the gas pedal manifold vacuum drops and the power valve enriches with more fuel. If you have a high numbered p.v. enriching can happen too soon and even a rich idle on a modified engine and too low number can cause a hesitation. ( vacuum secondaries on a 4 brl are controlled by venturi vacuum.