ijasond

I've been thinking about rebuilding and using my old Q-jet and getting rid of the Edelbrock I've got on my 425. Today I caught an episode of Musclecar completely dedicated to rebuilding, tuning and running "Quadrajunks" and the benefits of doing so. Lately it seems that everywhere I look something is telling me that I should have listened to the guys on here that have been saying it all along.
Once again, I learn the hard way. Well, at least I never sold it...

jensenracing77

i am terrible at making a Qjet run right but for me they are the best carb. i just have to have someone else tune it.

agtw31

during world war II,my mom rebuilt carbs on B-17's.

she didnt know what she was doing ,but after a week tearing them apart and putting them back together,she learned.

that is how they taught her,through repetition


i think the quadrajet just intimidates people,just like an automatic trans does.
.
if you work on one part of the carb at a time,and get a good rebuilding book that doesnt hide the tricks from you,you can get good at rebuilding them.

there are several guys out there getting rich rebuilding thse carbs.

ent72olds

I just got tired of the edelbrock on my vista(no power, and was used on an edelbrock intake, only a year and a half old), I couldn't get the car to go much over 70 without straining. I was driving the car to the Nats the next day, and decided the carb wouldn't benefit me driving almost 500 mi each way. Took the q-jet off my cutlass, put it on the vista, played a little and adjusted a little and instant 10-15 hp. Car cruised 70 mph no prob with it fully loaded(car seats, kids, luggage, parts and wife) at 3000rpm with the jetaway(this has to go). Still needs some minor adjustments, but I need to sell the edelbrock now!

squirell

Erik,
Even though my C/S is super low miles,my Jetaway bucks and slips.
Turbo 350 with a lock up converter is going in this Friday.
I'll let you know what a differance it makes.
Supposed to be a direct bolt in too.

mugzilla

My car has the original carb, cam, etc...

It accelerates like a rocket with no flat spots ...

It corners with no starvations ...

It will do 15 sec. 1/4 miles and still gets 12 mpg ...

zed

I've always liked Qjets. Once you've pulled one apart a few times,you get the hang of them. I hate that term 'Quadrajunk'. Seems to me the guys that call them that just don't know what they are doing with them. (lol) I'm no carb guru,that's for sure but guys like Nunzi and others made them work well in the past. I find them to be reliable street carbs. Lots of info on the net about them.

kruss77

It’s like that with everything: people tend to “go-with-what-they-know”! Holley’s; Edelbrock’s; QJet’s; they all have their good and bad points. The Quadrajet is like anything else GM developed in-house: complicated -yet reliable when adjusted properly. One of the main things the Quadrajet was designed for was flexibility. Since it had to go on so many different engines, mated to so many different transmissions, all with different performance requirements, the Qjet had to accommodate all those variations with minimal impact on the overall design. For this reason, for those who know how they work, a Quadrajet is one of the most flexible carburetors around and is capable of accommodating just about any engine setup –as long as the Qjet is adjusted properly. My uncle (now retired and somewhat eccentric from years of working at GM’s V8 engine assembly plant in Flint, MI) was at one time regarded as one of the most knowledgeable Quadrajet rebuilders in the country. People from all over would send him their Quadrajets and he’d rebuild them and recalibrate them to their factory-original settings. At one time, he had the most complete inventory of primary and secondary metering rods and jets in the country –the result of years of scrounging around the myriad of wrecking yards in the greater Flint area scavenging Qjet’s off every make and model of GM car. As you might imagine, he thought that the QuadraJet was capable of doing anything –mainly because there wasn’t much he wasn’t able to make them do!

hotrodpc

I am trying to learn about Quadrajunks myself, and be able to rephrase them as Quadrajets. I have Holley's before on SBC street/strip motors and although the sky is the limit as far as mods on a Holley, I am not good at adjusting carbs myself and hate Holley. One little back fire and you are buying another power valve. Seems they don't hold an adjustment for even a tank of gas, and you let them set in a shelf for anything over 30 days and they leak like crazy. So no more Holley for me if I can help it. I did have a 64 Pontiac at one time with a 389 and factory Carter AFB. Never had problems with it at all. Paid a shop to adjust right with equipment and it did fine forever. I did take it off and used a Holley for about 6 months after all the problems with the Holley I put the Carter back on 6 months later expecting it to leak since Holley's did. Nope, did just fine and still held its adjustment. Then I decided to go Edelebrock Carter on my last SBC, again no problems as far as durability and dependability, but true, it did to seem to lack some performance over the Holley. That was way back then. Now back into the old school vehicles, I got this 84 454 Chev Truck with a Rochester that expected just to drink gas like I drink Pepsi. Nope, not so much. As long as I don't hot dog it and don't kick in the secondaries, it seems to get much better fuel mileage than I expected. And most of what I have seen, Olds seems to run well with Qjets, so I am probably going to stick with them for now. However, for me, its a slow tedious project to rebuild one. I am sure it'll get easier with repitition. Anyone know, how, what or where to get a decent bushing replacement tool and bushings? I have a Qjet that has throttle plates seized and told I am going to have to hammer the shaft out and install bushings. I also have another one that has a bad vac leak right at the throttle plate linkage in need of a new bushing.

bullet1

can anyone recommend good manual on how to rebuild qjets?
thanks

hotrodpc

I have not seen this book, but I am going to guess its better than the one I have. I have the Rochester 1987 book by Doug Roe. Its a decent book too, but its a bit dated now. Good info on the old carbs though. I would check into this or ask around for someone who has had it and likes it or not.
http://www.amazon.com/Rebuild-Modify...1246772&sr=8-2

Bobsw32

Go to your friendly junk yard and get any quadrajet and start taking it aprt and putting it back together before you work on yours ....Use Doug Roe's book and practice on that old carb first ......WIll make thing much much easier

BLUE72RAGTOP

I bought a rebuild kit and book from:
cliffshighperformance.com
I'm just starting my build so we'll see how it goes

hotrodpc

Good luck with it BLUE. Take your time, and remove everything slowly. Sometimes those things seem like they are spring loaded and it just flies out of there and you do not get to see where it came from or where it went. One guy made a suggestion to me once and it seemed to work nicely. If you have a digital camera, before you even start, take pics of all sides, top and bottom, then as you take the air horn off, stop and take more pics, remove the throttle plate, take more pics. Take good clear pics. You don't have to download them. Then if you get into a bind and forgot something or can't remember how it went, THEN download your pics. Not saying you have to do it everytime, but its a good idea for your first 1 or 2. It worked for me in the past.

BLUE72RAGTOP

Thanks for the advice. This is the first quadrajet I've attempted to rebuild. I did take the camera to the garage and tried to go slowly. Nevertheless, when I turned it over after removing the top, two check *****, a small washer, and a spring all flew out onto the table. Maybe I'll figure out where they go, all I have to do is read a book first!