Still runnin' a Q-Jet? Seen the Oct. CT mag?

[unclewatts]

One small vote in favor of the Q-jet. I've had one on my 350 for twenty five years

[BCOWANWHEELS]

Man that holley in the pic looks good and bet ags goes through it like a water hose. What about when engine backfires and blows power valve

[68C15]

I took one off a 79 conversion van and recalibrated it to match a stock 72 truck. it runs great and the electric choke is more reliable than a divorced one. plus it moved over 12,000 lbs back from DesMoines with not a single problem.

[Robert1970C20rstbukt]

We never had a problem with a Quadrajet, all our trucks have 'em. My Grandpa taught me how to rebuild and tune 'em when I was 15 too.

[Jim_PA]

Originally Posted by prostreetC-10

Oaky 69GMCLonghorn......you and I need to team up to fight the forces of evil when it comes to the Q-jet villians and their leader PA Jim! I have a small Holley business/hobby I run out of my garage and have gotten to know them quite well. I've been doing a lot of the 750 HP's and they've been working out great. Here is a completed one. Granted, it's not nearly as pretty as a Q-jet, which is why I should be running 2 of them instead of my Holleys (LOL), but what are you gunna do.

Behold, the 800 CFM quadrajet (and please excuse my ghetto throttle linkage/return spring setup ). The second most feared carburetor in their nearly 20 years of production. The 800's were on many trucks in the late 70's. Second only to the early 70's Pontiac Super Duty 850 CFM quadrajets. If you come across a 71 or 72 Pontiac Super Duty Quadrajet, and throw it in the trash, you probably just threw $800-$1000 away.

I think I got this one for free. I recall offering a challenge to you -- Holley vs Qjet at the track, and I believe I never got a response



So... How do you identify an 800 CFM quadrajet??? Look inside the primaries, and notice the "hump" in the bore of the primaries right where the venturi booster meets the primary bore. Yeah, I know myself and just about everyone else doesn't need an 800 CFM carb, but the benefit to these is a stornger primary side (not as much of a need to crack open the massive secondaries...)

A 750 CFM quadrajet will not have this hump, it'll be smooth all the way around. Nothing at all wrong with the 750's either, WOT performance should be equal, unless you actually need 800 CFM's for your engine's breathing requirements (highly unlikely...)



If you have an 800 CFM quadrajet, give it to me. I'll gladly pay you for every one

[Dr. Evil]

Jim,
Could you please point to the hump. I am trying to identify mine and it would help. I am going blind in my old age.Seriously.

[shootiniron]

Anyone know where I can send a Q-jet to get properly rebuilt,or buy one??

[prostreetC-10]

Originally Posted by Jim_PA

I recall offering a challenge to you -- Holley vs Qjet at the track, and I believe I never got a response

What was that challenge again Jim??

You are right about those Pontiac stage "whatever" Quads. I think most of them have the straight fuel inlet. I always have a heart attack when I see a straight inlet at a swap meet. Problem is that some of the trucks also had that inlet. Have yet to score on one of those Pontiac Quads.

You only have PV blowout problems if you are not running the baseplate with the check ball protection. Most plates after 1990 have them built in. You can also add them to an ealier plate.


To the guy that asked about the I.D.ing between the 750 and 800 is inside the 750 there is a real small annular ring the restricts the air just a bit over the 800. The 800 venturi wall will be almost smooth all the way down with just a very small bump/hump. The 750 will have a more noticable hump. If you look at each one by themselves, it might be a little tricky but if you have both side by side, it's very easy to tell the diff. This link might help....

http://www.buickperformance.com/qjet.html

I just have to post this again. This is what 55 quadrajets look like in the back of my Toyato Sequoia. Bought all 55 for 150. It worked out to about 2.90 a carb. Sold them all on ebay and cleared a little over $4,000!!!

[C20-67_N_MO]

Originally Posted by prostreetC-10

x10

[C20-67_N_MO]

Okay to be fair I remember when I had a Q-Jet on a 455 Buick and that big ole boat Electra 225 moved!

But I would still rather have a Holley than that ugly mug of a carb sitting on my engine.

[vegaschevy]

Originally Posted by Sinister

Summit has rebuilt Quadrajets for $300.

They also have the holley carb with their name on it with an intake, and complete intake kit, and all mounting hardware for only 80 bucks more

[Jim_PA]

Originally Posted by Dr. Evil

Jim,
Could you please point to the hump. I am trying to identify mine and it would help. I am going blind in my old age.Seriously.

Directly down the primary bore from the hole where the choke flap goes, you see the egg-shaped bump on the bore wall? A 750 qjet does not have this bump. It is smooth all the way around.

BOP carbs mainly used the straight inlet. All (at least I think) Chevy's had the fuel inlet on the side.

[Jim_PA]

Originally Posted by prostreetC-10

What was that challenge again Jim??

I told you to send me a used holley that I'd return, and I'd run it back to back against my qjet at the track.

[prostreetC-10]

I couldn't do that to you Jim. It would just confuse your motor. If your intake is a spread bore, you would have to get an adapter to bolt up performance equipment and that might get your linkage and choke all messed up. The "waking-up" of your motor would probably float valves, bend pushrods and crack the case on that T-10. You probably wouldn't send my carb back after that and I'd have to report you to the board admin..........see how bad this could all turn out?????

Guess you would finally get into the 13's though......LMAO!!!!!

[Jim_PA]

Originally Posted by prostreetC-10

I couldn't do that to you Jim. It would just confuse your motor. If your intake is a spread bore, you would have to get an adapter to bolt up performance equipment and that might get your linkage and choke all messed up. The "waking-up" of your motor would probably float valves, bend pushrods and crack the case on that T-10. You probably wouldn't send my carb back after that and I'd have to report you to the board admin..........see how bad this could all turn out?????

Guess you would finally get into the 13's though......LMAO!!!!!

Nice try, but the Performer RPM spread bore I am going to install accepts both carbs.

[Dr. Evil]

Thank you Jim .
My truck is a total survivor and it was sitting for 10 years. Changed the filters and she is running awesome..Lots of torque...My wife and kids fight to get a ride in it...Q-Jet are complicated and you need to be on your game...If you want cheap ( inexpensive ) and easy = Holley. If you want something that is the real deal = Q-Jet..

[Sport/Truck]

I'm running one the only issue I had was it was loading up with fuel (flooding).
I checked the fuel pressure and was running twice the pressure it should be.
The quick fix was installing the magnafuel pressure regulator.
s/t

[ChevLoRay]

I had a '67 Pontiac Firebird Sprint, with the 230 OHC engine, dual exhaust manifolds and a Q-Jet. What impressed me was the way it could handily clean up a 289 Mustang. I put a set of baby turbo mufflers on it and had true dual exhausts when I had the pipes run from the stock manifolds.

Shoulda never got rid of it.