Q-jet cfm?
Thread Starter
Cruising
Joined: Apr 2005
Posts: 10
Likes: 0
From: Statesboro GA
Q-jet cfm?
69 350/350
I will soon be having my engine rebuilt. I cannot find the cfm specs. on the original Rochester QuadraJet carb.
To make the proper upgrade - I would like to know what I have now.
Where can I find the specs?
I will soon be having my engine rebuilt. I cannot find the cfm specs. on the original Rochester QuadraJet carb.
To make the proper upgrade - I would like to know what I have now.
Where can I find the specs?
Last edited by vetteDreams69; Nov 24, 2005 at 10:29 PM.
Le Mans Master
Joined: Nov 2004
Posts: 6,434
Likes: 0
St. Jude Donor '07
Originally Posted by page62
750 cfm. But why do you think replacing the Qjet is an "upgrade"?
Race Director
Joined: Oct 2002
Posts: 12,065
Likes: 2
From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
if you have a moderately modded small block for street use, a Qjet that is set up well and is in good working order will do everything you need it to!
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
You can pass on the high-flow fuel filter -- the stock unit will handle more fuel flow than you ever need. If you used as much fuel as a high-flow filter can handle, you'd have trouble making it to the gas station! 
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
vetteD -
If you're going with the upgrades you mentioned, including the headers, bump the stock jet size on the Q-Jet up 2 sizes. This will produce much better throttle response, and will prevent a slight lean condition from your improved exhaust system. Be sure to check the stock jetting configuration for your carb and use that spec as a baseline for your tuning - most of these old carb have already been "creatively" jetted, so you can't trust the jetting in the carb to be "correct."
If you're going with the upgrades you mentioned, including the headers, bump the stock jet size on the Q-Jet up 2 sizes. This will produce much better throttle response, and will prevent a slight lean condition from your improved exhaust system. Be sure to check the stock jetting configuration for your carb and use that spec as a baseline for your tuning - most of these old carb have already been "creatively" jetted, so you can't trust the jetting in the carb to be "correct."
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