Quality Quadrajet Carb?

At 9200 feet we fuel inject everything. For tin foil hat reasons I want one vehicle with points and a carb. This is my plow truck, it has to start at altitude and cold weather without drama and push snow. It may never see second gear for the rest of it's life.
 
Oscar11 said:
I had Bruce from Carburetors Unlimited build a Q-jet for my AMC 304, this thing has never ran so good! He is very knowledgeable on Q-jet’s and has a ton of good cores on the shelf. He’s located in Peoria AZ, his number is 623-399-0179. I don’t think he has a website. It’s definitely worth calling him, highly recommend.
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He’s 83 years old now. When did he build your carb? These carb guys are all old (like me) and aging out. Just like my 56 year old quadrajet….not much left to work with.
 
OVERKILL said:
Working with antique boats, I grew to hate carburetors, that's why when we went used boat shopping, we got one with SEFI. Have you considered a drop-in fuel injection kit? I've used one of the Holley ones and it's surprisingly good, and VERY easy to setup.
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Yes. It may become a reality after I ditch the choppy cam that this 350 Pontiac now has. Low manifold vacuum makes tuning most any fuel system challenging. In my opinion low vacuum producing engines are finicky to weather changes, cold or hot, and never ever idle at a consistent speed-setting. Classic cars can sound mean but the trouble that sound causes isn’t worth it. I’m done with headers, performance camshafts, and stinking rich fuel systems. Aiming for a tame-smooth running engine. At least fuel system issues won’t be caused by low vacuum and turbulence that hipo camshafts cause…Rant over
 
PontiacHO said:
Yes. It may become a reality after I ditch the choppy cam that this 350 Pontiac now has. Low manifold vacuum makes tuning most any fuel system challenging. In my opinion low vacuum producing engines are finicky to weather changes, cold or hot, and never ever idle at a consistent speed-setting. Classic cars can sound mean but the trouble that sound causes isn’t worth it. I’m done with headers, performance camshafts, and stinking rich fuel systems. Aiming for a tame-smooth running engine. At least fuel system issues won’t be caused by low vacuum and turbulence that hipo camshafts cause…Rant over
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I was also going to suggest that you give a few minutest thought into fuel injection. A throttle body EFI works very well with lumpy cams when set up correctly, and in fact, in some cases, may clean up the idle. There are those who say EFI has trouble with cams that have a lot of overlap. It is possible some of those people don't know how to tune the EFI targets leaner, so the EFI can achieve a smoother idle. Remember, an EFI setup will use an O2 sensor, and attempt to achieve 14.7 to 1, which may not be the correct target for a lumpy cam.

Put another way, the vacuum signal that a hot cam produces, and that a carb senses is unsteady, and operational problems like stalling can result due to uneven fuel flow. The EFI can be tuned to provide fuel at a steady rate.

The good news is that EFI will adjust for temperature, altitude/barometric pressure, engine temperature and so on. The results are generally quite positive.

But with all that in mind, EFI generally requires a high pressure fuel pump and an O2 sensor or two. So it's not quite as simple as a carb replacement.
 
PontiacHO said:
I’m with you Sir but 40 to 50+ year old cores aren’t ideal anymore…
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That’s the issue. The actual casting of the Q-jet gets warped or worn.

When my Oldsmobile got up around 150,000 miles, the throttle shaft bores were worn, leading to slight vacuum leaks around the shaft.

I was considering having new bushings pressed into the Q-jet body, but I ended up deploying to the Gulf War, and selling the car before I left.
 
PontiacHO said:
Yes. It may become a reality after I ditch the choppy cam that this 350 Pontiac now has. Low manifold vacuum makes tuning most any fuel system challenging. In my opinion low vacuum producing engines are finicky to weather changes, cold or hot, and never ever idle at a consistent speed-setting. Classic cars can sound mean but the trouble that sound causes isn’t worth it. I’m done with headers, performance camshafts, and stinking rich fuel systems. Aiming for a tame-smooth running engine. At least fuel system issues won’t be caused by low vacuum and turbulence that hipo camshafts cause…Rant over
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It was true 30 years ago, and it’s true now, that your better off with less cam than you think you need.

The Oldsmobile mentioned above had a competition cams 252 (as it was then known) which was their lowest end in terms of duration and lift.

It was perfect.

Woke the engine up without causing idle problems. Nice smooth idle, with good mid RPM performance. It might have even gotten better MPG. The Olds was my daily driver. I rebuilt the 350 with new pistons, rings, valves, valve springs, cam and lifters. The bottom end on that engine was still solid at over 100,000 miles and just got bearings. It still had the Q-jet and GM HEI ignition.

I saw so many cars at the Auto Hobby shop on base with a lumpy idle, and guys trying to get them to run right, because they had put in too much cam, too much duration. Lift was fine, but you could get more lift back then through a roller rocker kit, and skip the hassles of a long duration cam.

That weak vacuum from a long duration cam makes for brake booster problems, idling problems, and, as you note, efficiency problems. A “street/strip” cam is really just for the strip. They’re a pain to live with if you want to drive the car like a car.

Something like this would be great in your 350: https://www.compcams.com/high-energy-206-206-hydraulic-flat-cam-sk-kit-for-pontiac-265-455.html
 
Last edited:

Holley Sniper EFI 550-869K Holley Sniper EFI Quadrajet™ Master Kit - Classic Gold

Are you tired of rebuilding the 50+ year old Rochester™ Quadrajet® (Q-Jet™) on your classic Chevrolet, GMC, Buick, Oldsmobile, or Pontiac? The Sniper EFI Quadrajet™ is here to help! The first bolt-on spreadbore electronic fuel injected throttle body system that does not require any additional...
www.holley.com www.holley.com

QJet style is more $$$ but time you change the manifold and all that , not a bad deal, plenty of them running around on lumpy cams.
 
Astro14 said:
It was true 30 years ago, and it’s true now, that your better off with less cam than you think you need.

The Oldsmobile mentioned above had a competition cams 252 (as it was then known) which was their lowest end in terms of duration and lift.

It was perfect.

Woke the engine up without causing idle problems. Nice smooth idle, with good mid RPM performance. It might have even gotten better MPG. The Olds was my daily driver. I rebuilt the 350 with new pistons, rings, valves, valve springs, cam and lifters. The bottom end on that engine was still solid at over 100,000 miles and just got bearings. It still had the Q-jet and GM HEI ignition.

I saw so many cars at the Auto Hobby shop on base with a lumpy idle, and guys trying to get them to run right, because they had put in too much cam, too much duration. Lift was fine, but you could get more lift back then through a roller rocker kit, and skip the hassles of a long duration cam.

That weak vacuum from a long duration cam makes for brake booster problems, idling problems, and, as you note, efficiency problems. A “street/strip” cam is really just for the strip. They’re a pain to live with if you want to drive the car like a car.

Something like this would be great in your 350: https://www.compcams.com/high-energy-206-206-hydraulic-flat-cam-sk-kit-for-pontiac-265-455.html
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Even though this is a “small” camshaft, the 110 lobe separation is what I’m avoiding. Less vacuum. If it were on a 112-113 it would be ideal. Thanks.
 
PontiacHO said:
He’s 83 years old now. When did he build your carb? These carb guys are all old (like me) and aging out. Just like my 56 year old quadrajet….not much left to work with.
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He built it last year but I just recently got it installed and running ( the jeep was out of commission for a while). I knew he was older but didn’t know his exact age. He’s super nice and seems to know his stuff, I'm definitely happy with what he built for me.
 
Modern retrofit EFI is far superior to any carb, even the Q-Jet. If my 2 60's cars were not so original, a FI unit would greatly increase drive-ability starting with right-now starting.

My '65 Oldsey uses the 4-Jet, which preceded the Q-Jet, and uses a different manifold. In '66 they used the Q-Jet. Of course the '68 Vette L36 (base 427/390) used the Q-Jet.
 
When I had to replace the BBC's in my fishing boat, I went with a couple, one of which runs in reverse, rebuilds from Promar. Not a plug; they treated me well and after 8 years the engines still run well with no oil burning or other issues. Other than salt water problems with the manifolds.....But I tossed the old Qjets and bought an edelbrock performer manifold and marine carb setup. My carb guy told me the old Qjets were done for and hard to get parts for; he recommended the Edelbrock setup. The carb shafts and rods are teflon coated which works well for marine as they aren't used constantly like street use. So not sure what the negativity re: Edelbrock vs qjet is about. Obviously very different environments; but works well for me.
 
srfdude said:
When I had to replace the BBC's in my fishing boat, I went with a couple, one of which runs in reverse, rebuilds from Promar. Not a plug; they treated me well and after 8 years the engines still run well with no oil burning or other issues. Other than salt water problems with the manifolds.....But I tossed the old Qjets and bought an edelbrock performer manifold and marine carb setup. My carb guy told me the old Qjets were done for and hard to get parts for; he recommended the Edelbrock setup. The carb shafts and rods are teflon coated which works well for marine as they aren't used constantly like street use. So not sure what the negativity re: Edelbrock vs qjet is about. Obviously very different environments; but works well for me.
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Like motor oils, there’s loyalty among carburetors. I’m a fan of quadrajets but they are now so old even if they haven’t been rebuilt 6 times in 50 years there’s wear and corrosion. Like any carb, there’s likely to be some tuning that takes place and that’s the angst against whatever brand. It definitely takes some research.
 
PontiacHO said:
Like motor oils, there’s loyalty among carburetors. I’m a fan of quadrajets but they are now so old even if they haven’t been rebuilt 6 times in 50 years there’s wear and corrosion. Like any carb, there’s likely to be some tuning that takes place and that’s the angst against whatever brand. It definitely takes some research.
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I know the poster above hates the aftermarket versions, but there are some good reviews too. I suspect that would probably work out OK once tuned. He's probably correct, it may take a few tries to get a good one from Summit.

Which brings up the point, there are a bunch of YouTube videos on this. PRW makes a new version of the Qjet, with adjustable jetting +/- 15%. Kind of neat!

 
Cujet said:
I know the poster above hates the aftermarket versions, but there are some good reviews too. I suspect that would probably work out OK once tuned. He's probably correct, it may take a few tries to get a good one from Summit.

Which brings up the point, there are a bunch of YouTube videos on this. PRW makes a new version of the Qjet, with adjustable jetting +/- 15%. Kind of neat!

Click to expand...

Yep. Just someone with a concept. “OUT OF STOCK” on all of them on their website. Resembles the offshore (Chinese) knockoffs.
 
Edelbrock used to make new Quadrajets but abruptly stopped. I think it was a patent issue or something. I would love to have one of their Performance ones.

As others have suggested, a modern EFI carb retrofit would offer instant starting and improved drive-ability. If my 60's cars were not so original, I would have tried one long ago.
 
JeffKeryk said:
Edelbrock used to make new Quadrajets but abruptly stopped. I think it was a patent issue or something. I would love to have one of their Performance ones.

As others have suggested, a modern EFI carb retrofit would offer instant starting and improved drive-ability. If my 60's cars were not so original, I would have tried one long ago.
Click to expand...
Yes.... there are lots of really good Carb to EFI conversion kits that can be found all over these days. A person would be looking at about $900 to $2500 and up. Most are very easy to set up BUT like said, originality goes out the window with one. There are so many carb that are made today that can replace the quads as well as lots of replacement quads available its really all there for the choosing...
 
JeffKeryk said:
Edelbrock used to make new Quadrajets but abruptly stopped. I think it was a patent issue or something. I would love to have one of their Performance ones.

As others have suggested, a modern EFI carb retrofit would offer instant starting and improved drive-ability. If my 60's cars were not so original, I would have tried one long ago.
Click to expand...
I bought a new Edelbrock Quadrajet back when they still made them and it's still on the 396 BB in my 70 Monte Carlo. It's been a great carb and has been on the car since the late 90's.
 
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