Q-Jet questions

Discussion in 'The Venerable Q-Jet' started by lonegunm4n, Apr 12, 2014.

  1. lonegunm4n

    lonegunm4n Member

    I'm the proud owner of an all original '70 Riv. I've been doing little tinkering stuff here and there as time (and budget) allows. It currently runs and drives, but was running really rich. I pulled the spark plugs, and saw the previous owner used the wrong spark plugs. In went new spark plugs, and decided to poke around the carb. After looking at some of the seals and internals, I'd say it's time for a rebuild.

    I looked up the carb number, and according to the forum, it belongs on a 1969 430 cu, not the '70 455 cu that's in the car. The carb number breaks down to being made in 1969, though everything else, like the numbers for Buick and an auto transmission, checks out. Is it possible for the carb to be made in 1969 and installed in a year model 1970 car? Also, most of the other q-jets I've seen don't have the dot zero and a dot after the number. Is there any significance to this?

    Also, has anyone ever seen a sticker like that? I'm not sure how well the photo shows up, but it says "Factory Tested Carburetor"



    20140412_180642.jpg 20140412_180646.jpg
     
  2. Briz

    Briz Founders Club Member

    I dont believe the original carb would have that sticker on it. However a 69 430 carb should work fine on your car. If your not comfortable rebuilding it yourself there are several good builders on the board that can get it up and running perfect for you.
     
  3. techg8

    techg8 The BS GS

    The "T" on the sticker is for TOMCO

    Its a Tomco remanufactured unit
     
  4. Cliff R

    Cliff R Well-Known Member

    Tomco built (butchered is probably more accurate) thousands of carburetors, they are "remanufactured" units. None of them will contain the correct internals to be correctly calibrated for the application. They are "generic" calibrations, which basically allows one part number to cover a broad range of applications. They were pretty proud of the "factory tested" label, but I haven't seen a single sample to date that had a calibrate anywhere near what the factory used, or one that worked as well either. Typically the will be "generous" for fuel delivery, as being a tad rich everywhere minimized customer complaints and returns, etc.....Cliff
     
  5. lonegunm4n

    lonegunm4n Member

    Which is one of the minor issues that is leading me to do a rebuild, she runs rather rich all the way around.



    Thanks everyone for your replies! Does anyone know what would be the original specs (metering rods, jets, etc) for a '70 Riviera with a 455? Since I am ordering a rebuild kit, would it be better to order a kit for a '70 455 or go by the carb number ('69 430)?
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The 1970 Riviera carburetor was a 7040247. It had .067 jets with .041 metering rods. It used AY secondary rods.
     
  7. carmantx

    carmantx Never Surrender

    If you are building it yourself, toss this one and get a good core to work with. A 70-74 Buick 455 carb each were same on the outside and finding one not molested by a big reman shop would be best option. 70 had 750 cfm while the 71-74 had 800 cfm.
    Order you kit and parts from from cliffshighperformance.com, (cliffr above) as he has best parts available and can provide what you need.

    Where are you in Texas?
     
  8. lonegunm4n

    lonegunm4n Member

    Ideally, I would love to find the right carb for it, as that was a year only carb ('70 Riviera), but money is the limiting factor. I can't afford to buy a carb then turn around and rebuild it, and I can't afford to buy an already rebuilt one. I'm confident enough in my mechanical skills to rebuild it (with the help of Cliffs book :laugh:), so I may just buy all the parts necessary to rejet it and set it up how it should so I can at least get her back on the road for the time being until I get the necessary fundage.

    I'm an hour west of Houston near 290.
     
  9. Cliff R

    Cliff R Well-Known Member

    It is NOT a good idea to start throwing jets and metering rods into any commercially "remanufactured" carburetor. Every orifice in those carburetors has been altered to accept a "generic" calibration. It is ALWAYS better to start with a "virgin" original unit, and completely/correctly rebuild it with modern components. It will be a better end result every single time, trust me on this one.......Cliff
     
  10. carmantx

    carmantx Never Surrender

    Check eBay. You can probably pick up a good core for $50 or so.
     
  11. lonegunm4n

    lonegunm4n Member

    Dang, I was hoping I could do that. Oh well, I guess I will save my pennies and go that route then. Thanks for the heads up and saving me money and headaches! :TU:
     
  12. Cliff R

    Cliff R Well-Known Member

    Not a problem. The good news is that early Buick cores are pretty common and not overly expensive. If it were mine I'd build a 71-74 455 carb for it, a little more cfm, and plenty of those around are reasonable prices. Avoid anything pre-1969, crappy float set-up, leaking bottom plugs, and just not nearly as well made as the later units.......Cliff
     
  13. lonegunm4n

    lonegunm4n Member

    I found a 71 GS 455 Stage 1 carb on a local Craigslist. Would I be able to use it even though it's a Stage 1, or would it be best to find a regular 455 carb?
     
  14. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yes. That's exactly what you want. 800 CFM.
     
  15. Racerx88

    Racerx88 Platinum Level Contributor

    If it's a TRUE '71 Stage 1 carb (#7041242), I'd buy, resell it, and make enough off it to fund a good #7042240 or something similar. a good #7041242 should be worth upwards of $600. :TU:
     
  16. lemmy-67

    lemmy-67 Platinum Level Contributor

    Just find a decent 800 CFM core, and either get a vendor off the board to rebuild it, or get Cliff's book and get the parts to do it yourself. Either way, you'll end up with a great carb that'll make that 455 run like a champ. The 800 CFM carbs are best for the BBB...they have several improvements over the older 750 CFM designs, and are both more reliable and yield better performance.

    Stay away from remanufactured carbs...those have all been ruined in order to save cost and make a car pass smog tests. That's all they're good for.

    I have a 100% factory-correct 67 Q-Jet on my Riviera with my choice of rods/jets installed, and the car purrs like a kitten around town. Roars nicely when I drop the hammer, too. I just found some cores, bought the parts I needed, and rebuilt them by myself. I still have at 72-issue 800 CFM carb to try out...just need to fabricate the correct fuel line for a front-mounted inlet.
     
  17. lonegunm4n

    lonegunm4n Member

    It wasn't a GS 455 carb, much less a Stage 1. Heck, it wasn't even a Buick carb. Oh well, time to keep looking.
     
  18. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    I have so many needles jets, secondary rods that I look at them and say , you know im only using the num 75 jets and , 52 M rods , I have no intentilon of making less power with the 50 or so pairs of lower num jets and rods and hangers. Im willing to send combos out for free if you send me a self addressed cd mailer or somethiing you trust not to get mangled the way the delivery loves to do. I dont want money , I just cant throw them away. Maby a hollow bick pen would keep em safe.
     

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