Quadrajets, found a few. Stickers

Discussion in 'The Venerable Q-Jet' started by carmantx, Sep 9, 2018.

  1. TexasT

    TexasT Texas, where are you from

    Ive seen more than one individual that stores their stash in a/several school bus(es). Cheap weather tight storage. And if you pull it off the chassis and set the body on the ground the back door is easy access. Pull the seats and install some shelves and you have a little warehouse.
  2. Brad Conley

    Brad Conley Super Moderator Staff Member

    The new rage here is shipping containers. For around $2000 they will sell, transport and set up one for you. Not the most aesthetically pleasing but they are pretty much weatherproof sealed storage.
  3. carmantx

    carmantx Never Surrender

    Some updates on our sorting through all of these early Quadrajets. We still have about a thousand left to go through. Slow process to catalogue and store each one. There are so many rare Chevrolet high performance units, Pontiac Ram Air, Olds, Ford Cobra Jet and more. It is amazing sorting through these. Here are a few of the Buick Quadrajets we have found that are a bit special.
    7028243. 68 400 4 speed
    7028245 68 350 4 speed
    7029245 69 350 4 speed
    7040245 70 350 4 speed
    7041242 71 Stage 1
    7041243 71 455 4 speed
    7041245 71 350 4 speed

  4. NZ GS 400

    NZ GS 400 Gold Level Contributor

    Thanks for the update!
  5. 2manybuicks

    2manybuicks Platinum Level Contributor

    What was the name of the guy / business? I might have done business with him 15 years back but have CRS. (PM me if you are uncomfortable divulging said info on a public forum.)
  6. Brett Slater

    Brett Slater Super Moderator Staff Member

    This is turning out to be an amazing haul!!
  7. scubasteve455

    scubasteve455 Well-Known Member

  8. newmexguy

    newmexguy Well-Known Member

    Referred a guy on the Steves Nova Site to you. Guess he was looking for a 1971 Chev Nova 350 4 speed carb. Believe the # was 7041202 as I recall. Would not mind having a correct 1976 Chev truck 350 4V auto carb, if you have one in that stash. No great rush, am pulling the original engine out over Xmas vacation for a rebuild. Do have a early 70's pass car 454 quadrajet core and a '72 #240 Buick 455 quadrajet core that could send as partial payment. Let me know when you have time. Dave S. dona Ana NM
  9. carmantx

    carmantx Never Surrender

    Thank you Dave.
    We do have a 76 Chevy pickup 350 available too.
  10. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    What are some of the things you have never seen.?
  11. carmantx

    carmantx Never Surrender

    Long list really, but sorting through several thousand Quadrajets over the past few months, it is amazing the different stamping styles that were used. We have many bodies with no stamping at all, in all different makes. We see many variations within a specific quadrajet code from early production to late production. It appears, just like the vehicle assembly, that at times, the carb plants just grabbed what would work and assemble. Just creates some interesting variations. And proves that it is near impossible to know, and therefore recreate, what came off the assembly line. Even our engineering masters have some variations that never made it to production.
    Probably the most frustrating thing is seeing some repair attempt methods from other rebuilders. Thankfully most we have were original cores, but some were reman units.

    Still haven't found a 7040243, but do still have the 7040245
  12. gs66

    gs66 Silver Level contributor

    Sounds fun, like searching through a bag of old coins and finding some rare ones!
  13. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Mr. Mark
    did you find or do you have any 17056263 3435 AJA cores and what do you get for them?
    I have one that is modified and would like a none grinded on one to compare. Also to break in my motor with.

    I have stg2 heads and b4b, 290h cam, headers 3 inch exh

    on my last motor with iron big valve heads this carb ran 76 jets, C hangar, 52M needles, secondary needles DX/DR I think thouse are turbo sec needles only ones ive seen with 4 letters on each.

    Do you have a combo with idle tubes and idle channel restriction size recomendation? Combo being above mentioned
  14. Cliff R

    Cliff R Well-Known Member

    "did you find or do you have any 17056263"

    1976 Pontiac 4 speed carb.

    Any 1976-79 Pontiac carb from a 350 or 400 is functionally equivalent, and the 301 carbs just need a little help to get there.

    In a 17056263 using 76 jets with 52M primary rods and DX secondary rods would be off the mark some. Too lean on the primary side and too rich on the secondary side.....might even out in the middle someplace?

    I use a 17057274 on my own engine. To date I've dyno and drag strip tested it against just about every "high performance" carb out there. This included several very well prepared 850 Holley DP carbs, 850 Demon, Quick Fuel, Edelbrock 750 AFB clone and 800 AVS clones, and a big CFM Thermoquad. We even took it to a private track rental with 8 other carbs and swapped them back and forth on two different vehicles making runs all day long. When the smoke cleared and dust settled my 17057274 Pontiac carb was the winner in both ET and MPH.

    It's never had a grinder or sanding roll touch it, just a slight recalibration from stock and a higher flow N/S assembly and one of our HP accl pumps. I only use .073" main jets in it, 44 full tapered rods with .026" tips and custom machined secondary rods. It makes best power on the dyno in average air with .048"-.052" tipped rods with long tips. In really hot/humid air or DA over about 3900' I'll go even leaner.

    It's "pig" rich with CC or DX rods in it........FWIW.......Cliff

  15. Dr. Roger

    Dr. Roger Stock enthusiast

    I always wondered by the Buick Quadrajets had different color round stickers on them. Some have blue, some have orange, I thought it was a year thing. I always keep them on for originality (and they are hard to get off).
  16. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    So i should probably richen up the primary side and leave the sec side alone for starters on my new motor and adjust from there.
  17. Cliff R

    Cliff R Well-Known Member

    I will have built more 1976-79 Pontiac carbs identical to your 17056263 than anyone who will read this. I have them sitting on engines clear up to 750hp and running solidly into the 9's in the 1/4 mile.

    Biggest jet I ever put in one was a .073, and most use secondary metering rods in the .040-.050" range unless the air gets real crappy and we might lean them up to something in the .052-.058" range.

    M series primary rods were designed to be used in the 1979 and later SMAB (Single Main Airbleed) carburetors as they have a .010" taper on the upper section and .036" tips. The SMAB models produce a cleaner fuel curve as they use less emulsion air than previous models with two pairs of MAB's. The SMAB's are also "indirect". Your 4 MAB unit has one pair indirect and one direct so is calibrated with the later shorter metering rods, J, K, L, or P, not M.

    You can still use M rods in an early carb but if you calculate the metering area it requires pretty big jets to avoid a lean condition and heavy and WOT throttle. It's proportional to the upper MAB size, so you can actually install smaller upper MAB's to kill some of the air and use M rods successfully, but really a lot of effort vs just using the correct rods in the first place.....IMHO.

    The factory used fat tipped "DB" rods in most of those later Pontiac carbs on the 350's and 400's and they weren't that far off at WOT. Going clear down to DX (turbo carb secondary rods) would be "pig" rich at WOT assuming you aren't sucking the fuel bowl low or near empty on a hard run (common problem).........FWIW.......Cliff
  18. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    I wonder how I got the wrong needles in there? I was thinking I wanted to give it the gusto at wide open so I put the .076 jets in. For cruise I paired it with the .052M needles being they were the fattest needles I had.
  19. Cliff R

    Cliff R Well-Known Member

    Absolutely the biggest "myth" in this hobby when it comes to fuel delivery.

    The more efficient you make your engine the LESS fuel it will require in terms of A/F ratio. If/when you build an engine and takes steps to increase combustion efficiency, such as tighter quench, higher compression, improved camshaft events, etc, the engine will have improved VE and BSFC.

    As mentioned above the biggest jet I've ever used in one of those units was .073". Most need some additional "range" at part throttle so we use a tapered .044" primary rod in them with a .026" tip. "M" series rods are "stepped" with a .010" taper on the upper section and larger .036" tips. Not a lot of "range" with the APT and less fuel at heavy and WOT even with larger .076" main jets vs the factory .070 or .071's it came with.

    I don't think you're off far enough to hurt anything simply because the Q-jet will increase fuel delivery based on engine demand, (air flow thru the carb and pressure differential above and below the venturi areas), they are amazing when it comes to that sort of thing, and it keeps folks out of trouble as well.........Cliff
  20. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Here is what im working with.
    Idle tube: .038
    Idle down channel: .065
    Upper idle air bleed: .065
    Lower " " " : .071
    Idle bypass air: .092
    Mixture screw holes: .084
    Main air bleed in main body: .058
    Comparing to the nums in ur book I look on the small side of all the holes. Turning the mixture screws in all the way did not stumble motor and barely lowed rpm. 3 turns to 7 turns out no differance. Only thing is it was smooth, and on the lean side. Rpm would increase with a touch of carb clean at the primaries.
    Last edited: Mar 29, 2019

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