I have been all over the place on the which carb do I want ordeal,

I keep coming back to the qjet might just be what I want but in that comes all the cons ranging from a good core to being at the mercy of one of the qjet gurus,

I was looking around the net qjets do they have their stigmas but people do actually rebuild them themselves with success,
on the qjets but the veil of mystique is lifting for me, I plan to order cliffs book, I have rebuilt more solex than I care to recall and while pretty darn simply compared to the qjet I believe I will tackle it.


I found this low end rebuild

http://www.vetteprojects.com/kstyer/quadrajet.htm

It doesn't address some important issues like leaking shafts or things that need to be sealed but it is down to earth ego free and shows what this cat did.

So have you rebuilt a qjet?

I would love to hear your story, success or epic fail, no judging just for the info on the subject.

And no, saying send it to lars or ruggles doesn't help any....
And naming some other make of carb you like better and or trashing the qjet isn't what this thread is for....

 

I bought Cliff's book, bought a rebuild kit from him and got a nice rebuildable QJet. I put the carb on the small block I built for my '71. It runs great. Throttle response is amazing. MPG is up by 3 mpg on an engine that makes 150 more hp than the old one. I would definitely go this route again. This was my first Quadrajet build. Before this, I had rebuilt a Holley for a Pontiac and Zenith Strombergs for my Triumph. Cliff has built a carb for me before for my '72 LeMans that turned out great, so I trusted his expertise.

 

Thanks for the link!

No story yet but hope to have one with a happy ending soon! And I will try anything once, or almost anything, after thinking about what is the worse that can happen???

So since my carb on my 454 68 Corvette has a mysterious past and believed to maybe be from an RV of all places, I upgraded to a 74 truck 454 q jet from ebay that needs to be rebuilt (ok, actually an upgrade for me, ha!), bought a rebuild kit, and bought Cliff's book. Having built a few Holley's and quite a number of outboard carbs, I am hoping I can follow the directions and have a reasonably successful outcome (I hope) with my first q jet. You might check out Lars' q jet papers too. Between Lars' papers and Cliff book, I think it is doable.

Please keep us posted on what you discover and if mine turns out to be a disaster, I will let you know, LOL's!

 

Thanks guys just what i was wanting a camaraderie type thread,

What I liked so much about the link is the fellow is just showing what he did what worked for him not all puffed up spewing.

Do you guys like cliffs book?
I will also look at lars papers I would assume that they have to be close in what works

I too believe i can do it, I have done the solex i mentioned many import bike carbs, a few holleys and several edelbrocks then a weber or two even a Zenith that had a leather pump seal.

I really love the idea of the qjet and the big secondaries when we need them,

Since i have no core and a great looking core could be trash and a poor looking core could be good I believe i will try to find a good looking edelbrock qjet a lot of things like the shaft bushings will already be done.

I am hoping more people will chime in

 

Do the Edlebrock Qjets have shaft bushings? I have a 1901 from 15 years ago, but I've never had it apart.

 

There was several models and then the 850 cfm hipo model and I honestly do not know why I thought all or some did have the shaft bushing but I seem to recall it....perhaps it's just some or one of them,
Perhaps I am dead wrong.

Problem is such limited info out there on them but since I always liked edelbrock stuff I give their qjets extra kudus....

I see them posted on ebay and hit a vendor the other day,
I asked "would this be a good carb for a mild cruiser 454?"
3 days later I get the reply, "yes"

When I hit jet I end up on the phone for close to one hour with a kind tech telling me what to expect from this or that what is good for me what is too big etc....you know how that all goes.

It's hard to separate the hobbyist from the true gurus

 

The primary shaft bushings aren't a big deal. It's been a while since my last rebuild, so I don't remember the exact dimensions, but: get brass tubing from a hobby shop that has the same ID as the shaft OD; using a hand held drill bit (Harbor Freight has a complete set for $20) ream (not drill) the base up to the lip that is in the bore just short of the air passages( the difference between the existing bore and the drill bit is so little that the drill bit will not drift off center) , cut off a 1" piece of the tubing with Loctite and gently hammer it in place using the lip as a stop, cut and file off the excess. Brass has the same hardness as aluminum, not as hard as bronze, but it will be good for a long time. I've done this on 5 qjets, and haven't had any problems. Also, while you are at the hobby shop (or harbor Freight) get a set of numbered drill bits. Use these bits to carefully enlarge all the passages a FEW thousands to remove corrosion that has undoubtedly reduced the orifice over the years. Walmart sells disposable aluminum baking pans that are about 10"x 10" and are a perfect fit for soaking the carb's castings in cleaner. Get Cliff's book and you'll have a nice carb when you're finished.

 

I re-did the Q-Jet on my '71 when I got it. I bought my rebuild kit from Cliff and it came with everything I needed. As long as you take your time and be careful with the small pieces it is pretty simple. The hardest part was removing the old air bleeds with a small screw and getting the new ones in place without damaging the body. Once rebuilt I could let the car sit for days and it only needed 1 pedal pump and then fired right up in less than 3 sec of cranking. Crisp throttle response (for a low HP engine), and great drive ability.

 

Bats, I've read your post for years, this is well within your mechanical abilities. I rebuilt mine 19 years ago, only run non-ethanol gas, and it still performs well. It is a very satisfying experience, results are noticeable. Just do it.

 

If you find a good core from a 68-74 Chevy car (doesn't matter if it's a Corvette or not...but best not get one from a truck), you can rebuild it with reasonable skills. Ruggles book is a big help; but you need to actually READ it a couple of times to get a pretty good understanding of the carb.

The throttle shafts have to be pretty sloppy and worn to have a significant effect on vacuum loss. When you get the carb rebuilt and put it on the car, you can test for that if you have a concern. Warm car up, set at idle, and measure vacuum level. Then put Play-Doh or clay around the ends of the throttle shaft on either side to plug off any possible leakage between shaft and bore. If the vacuum level doesn't increase more than 1" Hg, ignore the leakage.

For bottom plugs, you should test for leakage to start. Take the disassembled carb body and pour some gas (or water) into the bowl. If the fluid leaks out the plugs, you need to seal them. If it doesn't, forget about it. If you need to seal them, I would drill out the existing lead plug and replug with JB Weld stick (cut & knead) epoxy. That should resolve any problem.

The only 'tricky' part to the rebuild is the reassembly of choke actuating arm to the choke rod. That arn fits over the choke shaft which extends inside the carb, and getting it all lined up can be a pain. If you need specific info on how to do that, send me a PM and I'll pass my method on to you.

Otherwise, it is a straight-forward deal to rebuild it. But you do have to determine if the carb you get has the rods/jets in it that came with that P/N. If so, chances are that unit has not been "abused" with any prior rebuilds; if the rods/jets are different, you may not know what you really have. Lars papers have lists of the rods/jets for Chevy Q-jets by P/N, so you can check out the carb you are working on AND rebuild it to specs for your '69 C3.

Finally, I'm not sure why sending your carb to Lars is out of the question. He is rebuilding carbs...if you request it via e-mail to V8FastCars@msn.com. Now, if you've "bad-mouthed" his posts in the past, he may not want to do it. That does seem to be a problem around here....

 

This is a pretty good link. While I've never done a full rebuild, I have pulled off bits to replace seals and seats as well as the accelerator pump. The key, I think, is to get a good core. When Lars rebuilt mine years ago, he ended up having to refurbish some stripped internal threads. I doubt I would have noticed them and then always would have wondered why my carb performed poorly.

 

I drilled out the well plugs on mine and replaced them with these:

http://quadrajetparts.com/secondary-...lug-p-122.html

Well worth the $9 in my opinion.

 

This guy does a pretty good job at explaining many of the parts and pieces during a rebuild....I have no idea how accurate his info is.

Below is part one...


Brian

 

Great thread and Thanks for all of the great advice and info!

got Cliff's book today and I am thinking you will earn a PHD in Qjets if you read it thoroughly. Great book! Highly recommend you get a copy.

also I read Lars stuff, numerous pages of great info and tips too, thanks!

(Out of curiosity, and no intent to commandeer Bats thread, but what is downside of installing a truck 454 carb? For a Sunday afternoon cruiser, I am thinking it would work ok for that purpose or not? I suppose you might change out the metering rods as needed if you wanted?)

 

I rebuilt a "truck" carb that I bought on ebay, rejetted it to Lars' recommendations per his papers and installed it on a 454. No problems and it went like a rocket.

 

This is as good a place as can be to explain my take on this, I have never that I know of bad mouthed Lars but I have said things that very easily could be misconstrued.

I have commented that I do not want to be at the mercy of any one "guru" on any subject and more so on a rebuilt part, what if my part that only the one guru can work on has a problem and the guru is no longer around, I am hosed,
( This means I need to at the very least learn the basics )

I also do not believe that lars, ruggles or any one person is the end of the line and the end all to be all with in this case qjets, so just like with other topics here I do get a bit irked when threads are high jacked to push one brand or person,
I find that as a big dead end to real unbiased tech talk, I like posts and offers like yours that for example you found the choke tricky and are happy to help with the way you tackled it.








Actually I like this type commandeering....

 

I first started working with Qjets in '83, as the unit on my 71 Monte had been "lovingly" rebuilt by a hack shop ,and was hurting. After struggling with several more rebuilds on it by different "well recommended" shops, I gave it a try. Figured I couldn't eff it up more than it was.

Bought the Doug Roe Rochester Quadrajet book, and followed the directions. It ran pretty good, and I was pleased for a first result novice. Shortly after I bought a really nice core (with a whole car under it) and built that according to the book. That carb is still on that car, and runs great. After several hundred thousand miles, I've rebuilt it a few times, had it rebushed once, and it still fires up easily and runs wonderfully. I have them on all of my carbed Chevys and on a 351W in a 71 Mustang, too.

Don't be afraid of a Qjet, find a nice core (or 2 or 3), get the books, and take your time building it. You have the skills.

Good luck,
Tom

 

Do a Holley spread bore rebuild and forget about it.

 

I'm gonna be a PITA and say, Do a Qjet rebuild and forget about it. What I have done many times with many miles (and smiles) with no issues

Holleys work great for many, some of us don't want one. We're discussing Qjets here, and what to do to make them thrive.

 

they have more stigma than the factory Rochester qjets, if not mistaken there were lots of models ranging from econo to 800 cfm but weren't they mech secondaries, will that be the best for a mild street cruiser?