Two Different '66 QJs

Discussion in 'The Venerable Q-Jet' started by GS Jim, Dec 3, 2013.

  1. GS Jim

    GS Jim Platinum Level Contributor

    Hi. I recently picked up a '66 QJ Intake with Carb attached. The Intake is dated 11-5-65. The Carb is different than another '66 Carb I have. One has the Turquoise disk on it and the earlier One isn't even machined for One. There are a few different things on the Air Horn as well. The Older One is marked in the usual spot on later QJs. But the numbers are 26240BMA and another number 3418. The One with the disk are 7026240MA. Which is a '66 QJ. Does anyone know what the difference is and Why?

    PONCH
     
  2. 36racin

    36racin Platinum Level Contributor

    Poncho
    I have the same carb 262408ma. I have a tread as we'll a few weeks ago. I'm up at camp right now. No internet service here so I can't figure out how to add the link to my thread. I'm sure someone else will chime in or you can search my threads and find it
     
  3. Cliff R

    Cliff R Well-Known Member

    The round tag carb will be an original production unit, the stamped number will be Service Replacement, with a later production date.....Cliff
     
  4. GS Jim

    GS Jim Platinum Level Contributor

    Thanks Cliff. I thought it might be in the First run because of the 11-5-65 Intake Date. With the different air horn casting on it too. Plus the over Two Hours it took me to get it removed from the Intake. And the Two Week soak in the basket and pail just to find the numbers.

    An Old Joke. Hey Cliff, drop over some time. :Dou:

    Thanks Again,,,PONCH
     
  5. wkillgs

    wkillgs Gold Level Contributor

    On those '66 carbs.... take a careful look at the aluminum plug at the fuel filter. The plug got loose on some carbs which resulted in a leak and fire! GM eventually, in 1974, issued a recall and repair kit consisting of a bracket that would prevent the plug from popping out.

    From the courts decision:
    >>>established the existence of a "defect" in the Rochester Quadrajet carburetors. When these carburetors were manufactured holes were drilled into them; these holes were later sealed by inserting metal plugs. One of the holes, in the fuel inlet portion of the carburetor, was sealed by a plug known as the "fuel inlet plug." If this plug becomes dislodged gasoline can spill directly into the engine, resulting in a fire under the hood. According to the affidavit of one of General Motors' own employees, a number of these fuel inlet plugs were improperly inserted during the assembly process.3 While only figures maintained in General Motors' central as opposed to its regional offices have been available in this litigation, and while all incidents of carburetor failures clearly may not be reported, the record discloses at least 665 reported incidents of engine compartment fires in vehicles equipped with the Rochester Quadrajet carburetor<<<<
    This was for Q-jets used on 1966 Buicks and Chevrolets.
     
  6. GS Jim

    GS Jim Platinum Level Contributor

    Great Info Walt, Thanks. I went and looked at the cleaner One. It has a plug on the side of the fuel inlet. Aluminum about 5/8" in size? I wonder why they drilled a hole and then plugged it up. I didn't look at the other One. It's back in the dunk tank. I got all of the Big screws out but no way is the top coming off. I'm just wondering what jets and rods are in there. Maybe another Two weeks in the bath it'll decide to let loose. The screws were hard enough..
    I got One Intake worked over. I painted it Green for the Stealth look. With the big air cleaner you cant tell a 750 QJ in under there. 2 More that I'm not gonna mess with.

    PONCH
     
  7. 36racin

    36racin Platinum Level Contributor

    Are all the qjet breathers chrome with the black top?
     
  8. Bigpig455

    Bigpig455 Fastest of the slow....

    No - some bodies and all lids were painted. The one shown here is a pancake style body with a "Big Car" style lid. The pancake lids are much flatter without all those ridges.

    That's a interesting shot of the service replacement carb part number - all the ones I've see had a seemingly 1971 part number - 7041304 or 7041309 (CA emissions?) must be from a different run.....
     
  9. GS Jim

    GS Jim Platinum Level Contributor

    The Plug on the One seems to be in there pretty good. I messed with it a bit and it seems pretty tight. But I'm still wondering why they did it that way. That Air Cleaner came with my Car. It just barely fits under there. I cant Imagine any other Cleaner fitting in there. Like someone said on here before. I'll bet GM lost money on Every GS they built in 65. With all of the things that they had to do to change things from a regular Skylark to a GS they had to loose. But the Muscle Car era was beginning and BUICK Had to do something! So this it what they did and I'm glad they did!!

    PONCH
     
  10. Bigpig455

    Bigpig455 Fastest of the slow....

    Think I see the answer on the carb # question - the 26240 service replacement is a Carter produced Q-Jet.
     
  11. Cliff R

    Cliff R Well-Known Member

    The plug next to the fuel filter housing was installed after they cross drilled the fuel inlets. This was only done on models that originally used the plunger type fuel inlet seats. The later screw in seats were not cross drilled. All 1965-1966 q-jets used this set-up, and some 1967's. The problem is easily corrected by completely filling the bypass area with lead during rebuilding, and installing a screw in plug in place of the pressed in one. The updated needle/seat assembly doesn't require the bypass and it got plugged anyhow. A quick pressure test of the fuel inlet will determine if the plug is leaking, and quite a few of them will show some seeping at the plug. This is often mistaken for a leak at the fuel filter housing gasket, causing folks to over-tighten the housing and strip out the threads trying to stop the leak......Cliff
     
  12. GS Jim

    GS Jim Platinum Level Contributor

    Hi Guys, Thanks for all the information. :TU: It looks like I wont be using either of the Carbs. I Really don't need an engine fire. I have a 750 I can install. I hope to give it a try today.

    PONCH
     
  13. 6WildCat5

    6WildCat5 Great Dale House Car

    You can get a newer 71 - 74 Buick 800 or a 76 to 79 on it as well depending on what mods your ready to take on... Dial it in, and go.. :3gears:

    I still use the late '67 unit on one, but I have noticed some small fuel leakage on that very front inlet plug this past season.. and am myself leaning towards a built '74 800 for it.. with the adjustable APT Screw mod..
     
  14. GS Jim

    GS Jim Platinum Level Contributor

    I put a re-jetted '72/750 QJ on it. MAN What a difference! That car was haulin ass. I put a 14" Air cleaner with a K&N filter. You could really hear the rear Two open up. Fun Fun Fun. But it snowed the next day and hibernation has set in. I wanted to try my 800. Oh Well. Time to tear down the '66/425. And paint it Green.

    PONCH
     
  15. 6WildCat5

    6WildCat5 Great Dale House Car

    Try and get a ram air cleaner on it... Even more fun...
     

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