i have looked in the search and found nothing on this. I know there is a Tech artical on it also. heres what i got for ya.....i found a good condition qjet off of a 83 chevy 305. i have a qjet off of a 84 lg4, so i was gonna mess with the other carb and try to "tune it for performance".. i have never taken apart a carb before and dont know where to start. i know there is a book, but what is it called and where can i find it? also, if i did all the mods that are in that tech article, what kind of performance increases would i notice on my modded engine (see sig?).. i just need to know if its worth the money/hassel...im getting the carb for only 15 bucks, but i dont know what else i would need to do all this. also, i have a non cc qjet sitting in my garage. it has been rebuilt, and hasnt been used sence. can i take that apart and swap over the "rebuilt" parts? i dont want to ruin a good rebuilt carb for nothing when i can go and sell it to someone that needs it. please let me know!

Ryan

 

The two books I have are: "Rochester Carburetors" by Doug Roe, and the Haynes q-jet manual. I got the Roe book on amazon.com, and they had both as a set at the time, but they don't appear to offer that right now. The Roe book is generally considered the better one, but the Haynes is alright, too.

Before my engine mods, I went from stock 17.4's (remember the altitude), to 17.2's with open element air cleaner, to 16.9's with the carb performance mods. I didn't have to touch the carb when I did the engine mods.

Basically the only things that will exchange between the non-CC and CC carbs are the accelerator pump, needle & seat, and float (and I wouldn't swear to any of those). Leave the rebuilt non-CC alone and get a kit to rebuild the CC carb. The kit instructions will probably include all the info you need, but the books are nice to have for backup.

 

where can i find the rebuild kit? i havent found any in jegs or summit. do they have the "adjust a jet kits" for qjets also? how much is that rebuild kit? and on a scale of 1-10..1 being the easiest and 10 being the hardest,, what would a rebuild be?

 

also, did you get worse gas mileage then before?

 

Rebuild kits are available from most any parts store: Pep Boys, Autozone, Checker/Shucks/Kragen, NAPA, etc.

You don't need adjust-a-jets with a CC carb, the computer does it for you. The secondaries are tuned via rod and hanger changes, and AV tension adjustment.

My mileage didn't change with the carb mods, because you're only changing the way the secondaries work at WOT. With the engine mods, mileage went down, from about 18-20 commuting, to 15-18 commuting (depending upon how many on-ramp test runs are conducted during a particular tank of gas...). I haven't had it on a sustained highway trip since the mods to know what that mileage is now.

 

sweet,, thanks for all your help!

 

Here's a good article.
http://216.117.149.191/ubb/Forum5/HTML/000598.html

I put an Edelbrock needle and seat instead of a GM one. Orifice size on the seat is .149 part number is #1980. I was running my float bowl dry at WOT when the motor was up to temps. No problems now.

 

thanks

 

in my opion and much experance with q-jet carbs thay are crap, i would just scramp together the money and buy a new carb or a remanufactured one from edlebrock or something. it would be easier in the long run i think...

thats my $0.02

§hean

 

Well, wasn't that special???

 

hmmm....300-500 for a new carb which i will have to pull the computer out of my car and change everything, or a used working computer controled qjet that i can rebuild and tune myself for probly under 50 bucks.......thats a tough one guys......(not trying to be a dick Squeeks83, i appreciate your opinion.)

 

Q-jets are not crap. It's people that don't know how to build them or tune them that think there crap. They can be made to run and look sneakier than slapping some huge Holley on it.

BTW, out of the box, Edelbrocks are not a good performance carb. For a SUnday driver, they work fine, but for all out performance they need work. Your better off sticking with a q-jet.

 

Just kidding, but they are not crap. They are just tricky. They are built ( the CCC) for emmissions, which believe it or not is good for you. A stock camaro can go a year or two without a tune up because of the computer control, it gets good mileage and runs great, how many holley equipped cars can do that?? Not many. Get the books read read read. The primary's can maintain an efficient A/F ratio for normal driving while the seconday's can be tuned for kick *** WOT performance. you can adjust just about everything so my advice is get the spare, keep running 5the stock one, and read the doug roe book,. then modify ONE thing at a time

 

thats what i plan on doing. is there a way to take the vacume advance thing off and make it run off of my HEI? im not sure if this one has it or not, they never got back to me in time to tell me before it ended on ebay. so i got it anyways....22.35 total with shipping.if it dont work, ill just put it back on ebay. i hope tunning it right will make a big differance. all my friends just put N2O on there rice burners and i cant keep up. i have more mods than just the carb tunning,, but still, i need to drop a second to contend!

 

this isnt the carb i bought,, still waiting to get it.. but it shows what im talkin about.

 

Thats part of the secondary airvalve/ choke pull off vacum break. most camaro's dont use one but the carb you have might require it, get the book its will explain what does what, in great detail.

as far as rice burners with N2O just keep running them until they run out or break an axel/tranny.

what is your set up. engine tranny etc. be specific so we can help you educate your civic driving punk friends!!!!

 

well one of my friends had a 14.5 second integra, then my other friend has a 13.9 sec probe. both on the juice. look in my sig for my engine specs, and its all connected to a th700-r4 tranny with 3.23's in back. soon im getting posi and 3.73's, a new cat back, pulleys, and then the carb tunning. not to mention suspension upgrades so i can launch better. right now i have 275/60r15's in back so it cuts my gear down a bit, but they help in the long run.

 

can i still use the carb if its got that vacume thing?? y doesnt mine have that?

 

Yes, i believe you just remove it.

By the way, as i've been refreshing my self as to how a CCC Q-jet works i am realizing what a resource the Doug Roe book and the Manual are. they explain everything. there is great info in the manual on how to properly adjust the carb. And the Roe book has lots of tips on how to performance tune it. Some items include setting up TPS, idle air bleed, idle mixture screws, lean stop, rich stop. Mixture control dwell. The roe book explains how to use different vacum breaks, make the seconday's open sooner. modify for adjustability, it has rod charts for the secondary's etc.

 

yeah im gonna order that book sometime soon. i should get my carb within a week, then im gonna start to work on it. how can i tell if it needs a rebuild, and do you gain anything from a rebuild besides reassurence?

 

a rebuild can never hurt, especially when you buy a carb you don't know the history of. Get a factory service manual and do the rebuild step by step, its going to take some time but you will learn a lot about how it works. Take your time. Do the stock rebuild and AFTER it runs good then look at the roe book for HP upgrades. BTW i just test drove my 383 and it spins the tires from a roll in first gear! It still needs some tuning ( ihavent put any meters on it yet) but it is coming along.

 

ok so i got the carb on monday...opend the package to notice a nice clean lookin carb. upon further inspection i noticed the choke was shattered!! i emailed the guy and he said it must be from shipping...but he packaged that thing up really good so i think hes full of $hit! how much will that be to replace? i will take pictures of the carb later so hopefully you guys can help me with other things