Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor

17059272 modifications

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Marx3:
Hi, I am building a 17059272 for a friend of mine.
The carb is in good shape and untouched.
It goes in a freshly built 454 early 90's truck engine. CR is beefed up to 9.4 and it has a Weiand Action Plus intake.
cam is an Erson 120201
288 adv.
492 lift
112 lsa

454 sits in a Deathproof clone Nova with M22 and 4.11 gears.

Carb has 72 jets/ 52P rods with DH sec rods.
I can measure the rest. Opening distance will be 1.3" and the pull-off realeases stock in about 2.5 seconds.

Do you think I need to modify anything anywhere ?

Marx3:
I measured things except the idletubes, they have clear passage, so I wont bother replacing them if the stock size is fine.
DCR: ~.045
Discharge: ~.025
lower idle:~.067
upper idle: ~.067
upper main: ~.070
lower main:~.040

jets: 72
rods: 52P
secondary rods: DH/.057
pull-off release time: ~2.5 seconds
open distance will be 1.3

I have a portable O2-sensor to measure AFR, but would like have it as close as possible as my friend lives far away, and I wont be dropping by to measure AFR's anytime soon.

ejowrench:
I have no idea what the cam specs are, but the closer they are to 'stock', the less mods you will need to do to the carb. I like to see what the engines wants before I dive in with a drill. J

ejowrench:
Go ahead and install the carb as is and get a feel as to what it wants. Make sure you can easily adjust the APT.  Make a lot of notes and use common sense.

My guess is that your main jets are a little lean, but try 'em any way.

Marx3:
Do you know the stock cam specs for a 1992 454 cam?

The cam is pretty mild. engine made about 13-15" hg when I visited him a while back. It has to be mentioned that this was with a stock 750 Edelbrock and without vacuum advance hooked up. I am positive it will be better with a properly set up Qjet.

As far as I know this carb might be from a 301, if this is the case it will propably need changes everywhere to work good on the 454. I know it is not from a 301 turbo, since the secondary rods are not the paperthin DX's...
As I wrote, I dont exactly have the opportunity to take the carb for a testdrive. If I could do this I would build the carb from guesswork based on the many Qjets I have build over the years using Cliff's advise.

Also, adding by-pass air might be a good idea, I dont know :-)
I dont mean to be rude, but I hope someone else will chime in...

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