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

Daves55Sedan · 01-06-2020, 12:20 AM

Not 100% sure about this, but I always thought that the power valve size had to do with the amount of venturi vacuum is expected to open the valve.
The standard size used in the Holley 2100's and Ford EBU's of 1954/55 on the 239/272 Y-blocks was 6 - 6.5
Not sure if the '57 and later carburetor configuration caused a difference in the expected venturi vacuum at the PV chamber.
Noting this because you mentioned that you are using 7.5 in your Autolite 2100. That is a '57 and later style carb, right? They are completely different from the pre 57 bug-sprayer type carbs.

01-06-2020, 12:20 AM	#16
Daves55Sedan Senior Member Join Date: May 2010 Location: Granite City, Illinois Posts: 3,008	Re: Y Block Normal Vacuum w/mild Perf. Street Cam? Not 100% sure about this, but I always thought that the power valve size had to do with the amount of venturi vacuum is expected to open the valve. The standard size used in the Holley 2100's and Ford EBU's of 1954/55 on the 239/272 Y-blocks was 6 - 6.5 Not sure if the '57 and later carburetor configuration caused a difference in the expected venturi vacuum at the PV chamber. Noting this because you mentioned that you are using 7.5 in your Autolite 2100. That is a '57 and later style carb, right? They are completely different from the pre 57 bug-sprayer type carbs.