Hesitation When Accelerating

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#1 (permalink)

06-04-2021, 05:41 PM

Moriarty

CC Member

Join Date: Jun 2018

Location: Seattle, WA

Cobra Make, Engine: ERA 427sc

Posts: 98

Not Ranked

Quote:

Originally Posted by eschaider

Out of the box, Holleys will almost always come with a 6.5 power valve. That means the power valve opens at 6.5 inches of idle vacuum. If your car idles at 6 or 7 inches of vacuum that means your power valve is open at idle creating a rich idle. You want your power valve to open at roughly ½ your idle vacuum. An engine with 6 inches of idle vacuum wants a pwervalve with a 3 inch opening value.

This was exactly the info I needed for the similar issue I had been chasing. Switched out the 6.5 for a 4.5, readjusted the transfer slot square and viola!

Thanks,
Aaron

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