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4053 carb power valves

Started by wisemanz28, April 21, 2022, 07:09:38 PM

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wisemanz28

Trying to figure out my power valve size. Wanted to share the pics and get the groups opinion. The first pic is the primary side, second pic is the secondary side

169INDY

Knowing what power valve you have is as easy as reading numbers. The face of this power valve has the numbers 8 and 5 on it. That means that this valve opens at 8.5 inches of vacuum.

Reference: Link
https://www.racingjunk.com/news/choosing-the-right-power-valve-for-your-holley-carburetor/
Jim
68 SS/RS L35 Th-400 LOS
69 Pace Car L48 Th-350 LOS
68 Z28 M21 LOS

crossboss

Just another T/A fanatic. Current lifelong projects:
1968 Olds 442 W-30
1969 Mustang Fastback w a Can-Am 494 (Boss 429)

wisemanz28

I also am seeing a number 6, I just wanted to be sure.

69DuskBlueRS/Z28

If you need a couple of 8.5" new Holley power valves, send me a PM.

rszmjt

First picture of the primary metering block has a 65, second picture of secondary block has a 85.
You read the numbers on the right hand side, the left side with the aplha numerical digit with a number underneath it is not a identifying number. You can also tell the higher value power valve by the effort it takes to push the other side of the valve although the difference between 65 & 85 is negligible.

Jerry@CHP

We've been using 6.5s with our restos.  They seem to work better for the street.

Jerry

vabeach56wagon

Have you considered plugging the secondaries' power valve opening, gone down 1 step in the the vacuum spring and increased the secondary jetting to 84-86?

crossboss

Quote from: vabeach56wagon on May 18, 2022, 08:44:39 PM
Have you considered plugging the secondaries' power valve opening, gone down 1 step in the the vacuum spring and increased the secondary jetting to 84-86?


Nope, don't do that.
FWIW, start out with the stock specs, eg: jetting (68/76), power valves, springs etc. Then IF needed, move up or down. When running, use a vacuum gauge. This will get your tuning spot on for a correct power valve. Also, make sure you do not have any vacuum leaks from cracked hoses, lines, gaskets, etc.
Just another T/A fanatic. Current lifelong projects:
1968 Olds 442 W-30
1969 Mustang Fastback w a Can-Am 494 (Boss 429)

Jerry@CHP

A good baseline is 72-76s.  That is standard jetting in the 3310 Holley carb.  If you're blocking the rear power valve, then add 4 to the rear jetting making it 80s in the rear. 

Jerry

vabeach56wagon

Do you stagger jet your 4053?
Do you use the bigger accelerator pump?
What size nozzles do you run?

paul