Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Dialing in your rebuilt Quadrajet carburetor => Topic started by: GSP7 on March 03, 2025, 07:43:13 AM

Title: Tuning/ Dialing in my new rebuilt Q jet
Post by: GSP7 on March 03, 2025, 07:43:13 AM

I do not see any where in Cliffs book on dialing in tuning my new rebuilt carb

I thought there was a APT adjustment section , but I dont see anything about adjusting the APT  , etc etc

Any help

Ive got a newly rebuilt 17080213 installed replacing my old 17080513 on my '81 chevy K20 4x4 truck with mildly built 350

Need info on dialing the carb in.   I guessed on the APT setting at 3 1/2 turns up . Original APT Setting was way wrong on this core carb I got off ebay that I rebuilt

.

Title: Re: Tuning/ Dialing in my new rebuilt Q jet
Post by: GSP7 on March 03, 2025, 08:49:49 AM

Is the a inclusive written guide to dialing in a new rebuilt q jet on a 350 chevy sm blk?

Timing, idle mix screws, APT adjust, vacuum gauge use, etc etc ?

Title: Re: Tuning/ Dialing in my new rebuilt Q jet
Post by: Cliff Ruggles on March 07, 2025, 04:21:46 AM

"Newly rebuilt"?

Who did the rebuild and exactly what was done to it?

Engine specs, compression ratio, cam card, etc?

What distributor and what has been done to it (how much timing does it add with the mechanical curve and VA)?

Tuning goes far beyond simply adjusting the APT screw.  You have to have the distributor working correctly and adding the right amount of timing as well.

The carburetors idle system must be set up for the engine, plus the right jets and metering, PP spring, etc.....