[53belair]

whats the cfm of a stock Q-Jet off an 84 chevy 350?

[Chevrolet4x4s]

4-500 cfm iirc
Shane

[302 Z28]

The basic Quadrajet used on any GM engine up to 400 cid is 750 cfm. On a mild 350 the air valve will never open all the way so the carb never sees it's full flow potential.

Vince

[53belair]

how can i get the most out of a stock Q-Jet
my brother once had a 4bbl Q-Jet on a 4.3 v6 and he some how modified it so it was a full time 4bbl
im just trying to get the most out of what i got for right now

[Jmark]

All qjets are capable of flowing 750 BUT......as stated before, the secondary upper butterfly controls flow and is set when built to each engine. You can file the limit tang on the butterfly so it opens to 85 degrees. (85 is prefered to 90 for some reason.) There were some super duty Pontiac engines that had 850cfm qjets but they are rare and hard to find.



Mark

[53belair]

hey thanks for the help

[Jmark]

Your welcome. If you have a simple plastic protractor, you can ck the current opening on your carb and see where it is. I've seen some that only open to 50 degrees, some will go to 80+. Grinding off the tang a little at a time will get it to the max flow easily.

There is an excellent qjet book by Doug Roe that is usually available cheap on eBay. Very good source on qjets of all kinds and flavors.

Here is Doug's book. (have and use it myself)

This is a new one that just came out. It sounds promising but I've not read it yet.

Mark

[53belair]

attempting to stay on budget but a little mild
im not sure if a stock Q-Jet is a wild carb or not
but i was just looking at dual carb intakes on jegs and they seem kinda cheap for something like that(about $265) and was wondering would it be hard to make some linkage for a dual Q-Jet set up atop a sbc 350

[Chevrolet4x4s]

linkage shouldnt be too hard dont over carburate it or youll lose throttle response

[poncho62]

Originally Posted by 53belair

was wondering would it be hard to make some linkage for a dual Q-Jet set up atop a sbc 350

Good luck finding an intake to take the Quads...................

[Bald Menace]

just an FYI, 71 and later Buick Quadrajets on 455 engines were 800 cfm carbs and can be modified to perform very well. I have used them to propel a 4000 lb car with 3.36 gears to low 12 second E.T's and yet retain decent mileage around town. a quadrajet is a mechanical secondary carb contrary to what many people may think..

[53belair]

Originally Posted by poncho62

Good luck finding an intake to take the Quads...................

a regular intake manifold wouldn't take Q-jets?
anyway to modify one?

[53belair]

i was looking at the Q-jet i got and it looks different
the tab it says to file down so it would open more is located differently

[Jmark]

Can you post a picture of your carb?

[53belair]

ill take a picture tomorrow,but if my memory serves me right,its different

i do remember looking for the word Rochester on there because i noticed it was different

oh and someone is gunna have to teach me how to upload pictures onto here