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ninjagin

'71 Electra - Carbeuretor Conundrum - need advice

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Hi folks!

Well, I had 'LeRoy', my 1971 Electra 225 coupe (455-4), in the shop to get the heater core replaced and the steering box loosened up just a teensy bit, and I reported that I'd been getting hits of gasoline vapor through the ventilation system at stoplights when I dropped the car off.

(I know, I should have heard the doomsday music playing when I told them about the gas fumes, so no fair telling me that "shoulda seenit comin". I was more concerned about not having foggy windows, of all things, in my defense, and I have been breathing antifreeze-soaked gas fumes for a few weeks, after all. -=wink=-)

Anyhooo, the carb needs a rebuild, they say. Yet, my first thought was "Heck, why mess with a day's labor on a rebuild ... just replace it!" So that's where I am, and I need advice.

The first thought on replacement was Holley. Then again, there are carbs to fit from Weber or Edelbrock in easy reach, too. If I'm contemplating replacement (and I am, most surely), what's the best quality option to seek for it? I'm not interested in hot rodding LeRoy, but there may be a performance advantage to gain. I'm probably most intent on reliability and fuel efficiency, if anything. (I'll save the old carb for LeRoy's next owner, perhaps, for whatever plans they might have for it.)

So, what's your advice? I'm hoping that NTX will offer his usual detailed analysis and kind encouragement, but the floor is open. What carb manufacturer carries the most weight, in this circumstance? Please let me know.

As always, thanks in advance for your kind consideration and perspective.

-- Randy

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...Anyhooo, the carb needs a rebuild, they say. Yet, my first thought was "Heck, why mess with a day's labor on a rebuild ... just replace it!" So that's where I am, and I need advice.

-- Randy

Sad. The Q-Jet is a great carb. The rebuild can be straightforward, and as simple as changing gaskets to a new alcohol resistant gasket set. I've had plenty of Q-Jet Buicks and found them very responsive.

But, if you are headstrong on replacement, consider that in order to take advantage of a larger carb, you will probably need a different camshaft. Otherwise you are pouring additional fuel into the stream with no place to send it.

Stick with the Q jet. One day to rebuild is a small price to pay.

just my humble opinion.

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Stick with the Q jet. One day to rebuild is a small price to pay.

just my humble opinion.

Thanks. I didn't expect to hear that, and I'm curious about the advice.

What is it that makes the Q-Jet a great carb?

What is it about replacement carbs that make them not so great (apart from not being the original Q-Jet)?

Can you help me understand?

Thanks so much for chiming in.

I appreciate the help.

-- Randy

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How was it running before going to the shop? There may not even be that much wrong with the carb. No carb is sealed like modern fuel injected cars and with the available highly volatile gas they ALL stink! And the carb may not even be the source of the smell. Check the rubber fuel and return lines at the fuel pump and at the tank.

You will not get a better matched carb than the original that came on the engine.

Willie

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How was it running before going to the shop? There may not even be that much wrong with the carb. No carb is sealed like modern fuel injected cars and with the available highly volatile gas they ALL stink! And the carb may not even be the source of the smell. Check the rubber fuel and return lines at the fuel pump and at the tank.

You will not get a better matched carb than the original that came on the engine.

Willie

It's running really well, actually. Tends to get a bit too rich when warming up unless I tap the throttle after the vacuum pops the vents, but even then it settles down and doesn't stall or cough when on the move. Acceleration is great, with no misses.

To confess, I have a cracked charcoal can and that's what I thought the smell was coming from.

It's not just a "little" gasoline smell, either... like you can chalk up to "character".

(I took a shower in gasoline a couple months ago when I was clamping off the fractured fuel pump that was on it.) It smells like I put on gas for aftershave. (Doesn't attract the ladies, though.)

I've checked the lines, and they are dry. When I had the fuel pump replaced, they fit a new hard line. It's not weeping and I'm not getting any grit on those connections to show something wet there. Could be that the gas is leaking, but dry by the time I'm able to leap out of the car and pop the hood, I suppose.

Aw heck, let me just ask this question:

I've rebuilt a carb before, 25 years ago in college, on a '80 Kawasaki 440 (2-barrel, 2 cyl), and put in new floats, jets, seals and gasket. Soaked it in gas for a few days after getting it off the bike. I left the plate intact and just cleaned things up with rags. It didn't take many tools, not doing the whole job, but it took the better part of a week of having my bike in the living room (protip: get cool roomates). Bike never quite ran the same afterwards (teensy bit sooty if not warm), but it ran. I've never tried to do anything like that on a car before, mostly because I'd rather not pay the idiot tax. With that limited experience, do you think I could I just rebuild it myself if I had a nice complete kit? How idiot-proof a process is it, given all the bits & pieces and a decent manual?

(I know you don't know me from Adam's off ox, but give an honest opinion.)

Thanks for chiming in on it. I'm very grateful for the perspective.

-- Randy

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REBUILD YOUR EXISTING CARB . . . PERIOD!

First, most of the carbs you see advertised are "universal fit" carburetors. That means "adapt to your application", which can take a good deal longer in labor time just to do that than it would to do the complete overhaul/rebuild of the existing QJet.

Second, the "universal" carb might physically fit the spreadbore manifold, BUT that's where the similarity can end. The carb's manufacturer will give a general CID size of engine the carb was calibrated for. This means fuel curve calibration . . . and will most probably be for a Chevy than a Buick . . . so then you'll need to rent some chassis dyno time at a local/regional speed shop to get the fuel curve (probably leaned-out) adapted to your Buick's engine characteristics.

Third, although Holley has listings for the earlier 1970s engines, in either square bore or spreadbore "stock" applications, if you look at the part numbers, you'll see that many are THE SAME part number. Incognito "universal" carburetors!

Fourth . . . none of these carbs are inexpensive! Most generally sell for $350.00 and up . . . new . . . or a little less for "refurb" (think factory warranty returns, for undisclosed reasons). Rochester QJets are somewhat more expensive to rebuild than other carbs, but NOT that much, I suspect!

Fifth . . . If you can find a reman (which Holley also has) carb for that specific year of Buick 455, getting a good one can be problematic. Although there can be some warranty involved on the reman unit, that will not compensate you for "pain and suffering" in having the reman carb changed or "worked on" to get it to do what it's supposed to do.

By this point in time, all of the quirks and issues which Rochester QJets can have should be very well-known OR discovered via Internet searches or from reputable Rochester carb books. They generally are a very bullet-proof carb for stock engines. Any leaks they might have should have appropriate "fix kits" for them, too. The most common is the "secondary well seal" kit, with several variations thereof. Many techs that rebuild QJets also smear some fuel-resistant 2-part epoxy sealer on the bottom of the well seal plugs for good measure (think "JBWeld").

IF there's wear on the throttle shaft, there's a kit for that too! Be sure to get a new float!

So, REBUILD WHAT YOU HAVE as it should be the least expensive way to go, PLUS all of the calibration work mentioned above will not be needed. Plus, any "warranty" for the work will be with your local shop, rather than somebody at the other end of a phone line. There's generally no "rocket science" involved in rebuilding a QJet, anyway, but there can be a few things that might require some consultation of a repair manual, on some carbs.

Just some thougths,

NTX5467

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There are no new carburetors (at least made today) that will even fit your intake manifold!

So, do you wish to also purchase and install a new intake manifold; or try to use an adapter. The carburetor on your Buick is either a 750 or 800 CFM carburetor. Using a new 750 through an adapter to your original manifold yields 525 CFM.

For any new carburetor you will also have to fabricate a new fuel line, possibly purchase a new air cleaner, and definately spend DAYS and DOLLARS recalibrating the new carburetor to run on your Buick. I don't know about transmission linkage, but it may need changing as well.

And chances are, when you have finished spending days and dollars, the Buick will NOT run as well as it currently does.

Suggestion: get a copy of the Q-Jet book written by Cliff Ruggles, a really good rebuilding kit;), the original Buick shop manual for your Buick, and rebuild the original carb.

Jon.

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When Jon says get a good kit, he's being modest. Get one of his. They're not the typical "zip kit" that's made to fit a bunch of different carbs. His are custom made to fit your carb.

Look at his website for more info. THE CARBURETOR SHOP

Ed

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Thanks, everyone, for your kind consideration and helpful advice.

Until I opted to post my conundrum here, almost everything I'd been reading seemed to point to replacement with an aftermarket rig (seems like every thread I came upon ended up having someone call it the "quadra-junk", "quadra-expetive" or some other interesting and colorful variation of those two). Over the past couple days, I've had the chance to take in everyone's input, watch some rebuild videos on YouTube, and poke around the web for kits and experiences. I discovered Cliff's website and read the excerpt he leaves for the "history" section of his book, and was surprised to see the '71 Buick Q-Jet held in such high esteem, actually.

Quoting from Cliff:

"in 1971 Buick improved the performance of its large-displacement engines by increasing the airflow capacity of its Quadrajets. Rather than expanding on Pontiac's approach, they simply enlarged the primary bore in the main body. Typically 1 3/32 inches in diameter, Buick's modifications increased bore diameter to 1 7/32 inches. Generally referred to by airflow capacity of "approximately 800 cfm," Buick continued using this design through 1974. Its advantage of additional airflow improved performance, but unlike Pontiac's approach, Buick's Quadrajet retained the velocity boosters for maximum throttle response and improved emissions... These early Buick carbs are an excellent starting point for a high-performance carburetor and are the only large CFM castings produced with divorced-style chokes." (emphasis by Cliff)

Long story short, it seems like rebuilding truly is the right way to go.

Yesterday, I figured that I'd have my shop rebuild it (they'd probably send it out), but looking over all the Q-Jet rebuild threads, and spending time at Jon and Cliff's sites, it's starting to seem like sending it off for a complete rebuild by someone who knows the drill (and the clever tricks) might be a good way to go, too.

On the other hand, If I just picked up a good kit and had my garage send it and my carb along to one of the specialist shops, maybe I'd get an acceptable result that way, with results that are decent enough with shorter turnaround. (No slight meant to Jon or Cliff, to be clear.)

Anyhow, I'm in a different conundrum, now, but I at least have a way forward. Many thanks to everyone for steering me in the right direction.

-- Randy

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I,m a little late on this thread, but your headed in the right direction. *Rebuild the Q jet. *I had a 455 with the Q jet, long time ago... days of young and stupid. *I tried a Holley, along with all kinds of other "tricks". *I should have rebuilt the Q jet and called it a day. *Rebuild it, ,don't repeat an error thats already been made.

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Hello again! Just wanted to follow-up.

I had my garage re-build the original Q-Jet, after asking if they'd had much practice with rebuilding carburetors. They said they do a couple every week and knew Q-jets pretty well, so I let them do it. They said it was leaking from inside, but could not tell me where "inside" that was.

It wasn't cheap, and they asked to keep it for a couple extra days to dial it in, but the results are good!

No gas smell in the cabin anymore. The car seems a little more perky, and I seem to be getting better fuel efficiency, but I'll have to wait until I get another tank of gas to get some numbers.

I'm pleased that it's all back together, and thanks very much to everyone for the kind and helpful guidance.

-- Randy

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