Advice on buying Rochester Quadrajet

Discussion in 'Engine Topic' started by falloutboy, Aug 17, 2019.

  1. jeff swisher

    jeff swisher Veteran Member

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  2. falloutboy

    falloutboy Veteran Member

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    Thank you
     
  3. jeff swisher

    jeff swisher Veteran Member

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    You are welcome.
    I do not know if when you search the internet if you get the same links pop up as we do here in the states.
    I would assume NO.
    May be a bit harder if that is the case to find things.
     
  4. budro6968

    budro6968 Veteran Member

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    For years I wired my choke open and dealt with a cold blooded B***H. I also bent the secondary throttle stop to let it open at Full bore any time I wanted.
     
  5. jeff swisher

    jeff swisher Veteran Member

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    That climate in Germany is much milder than we get and cold morning starts just about every day there.
    That would get old after awhile.
    I do not have a choke but in the cooler months I will twist out my Idle mixture screws to compensate.
    I did have some cold blooded motorcycles though the worst offender was a 1979 LTD 400 Kawasaki.
     
  6. falloutboy

    falloutboy Veteran Member

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    Indeed the climate is milder and wetter than what I experienced in the US.
    One reason is, German legislation doesn't "like it" if you let your car idle to warm up.
    But the main reason is, I have a steep curved driveway, and the back porch of my neighbor in direct line of sight. And he hates the car, me and my family.
    And with a working choke, I have the option to crank it, and drive just out of the driveway and down street and off I am. :)

    But still, I would have to get the car back together and running anyway :D
     
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  7. cnlmustard

    cnlmustard Member

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    No offense, but you seem to be new at this, but I'll put my 2 cents in on your choke question at end of my post.
    If you are going to anything inside a Q-jet, I advise anybody to get a copy of "Rochester Carburetors" by Doug Roe. ISBN 0-912656-10-7 ,if you can find it. He was the Q-jet master, and most of the book is that, he worked at Rochester before becoming a racing champion. Q-jet can be made to do things with any manifold no other carb can, esp. if you have the right one with all features. Some even had a factory altitude compensator bellows built-in! (see picture RED arrow, there's just a plastic fill piece here if that feature is not there.) I live in flatland, so I don't care.

    I like the model with the "part-throttle compensator adjustment" (BLUE arrow), which can be adjusted with needle nose pliers with NO disassembly. It adjusts at what load the primary rods will lift up to increase primary jet flow. Very nice, and not even in the book!

    Anytime I changed ANYTHING at all from stock with anything affecting the performance, even the car's muffler, I had to change something in the "carbie" to compensate. For any brand of carb, you need a collection of jets, jet-rods, intake needle/seats,etc., and to willing to do timing trials as well to optimize.

    DO NOT use this carb as is, like the other postings said, it obviously has been apart a number of times, and the grime tells us not recently. It needs a nice long bath in a pot of carb cleaner and a rebuild kit with all new gaskets. Since the seller went to a POS Holley, it's likely he went through this item and made multiple changes, possible breaking something before giving up on it. I've broken things when making multiple tuning changes, and have a few extra Q-jets for spare parts if I get careless. Use spring lock washers under the front large bolt hold downs to prevent damage and over-tightening.

    Your last question, yes. I switched to electric choke,I get a quick start, but it's completely off choke within less then a minute. But I've always had it in the deep south, I can't speak for colder climates. Tie the wire to your distributor hot feed and block off the internal vacuum port that pulled the hot air through into the hot air tube connection to keep dirt piling up on the element.
     

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  8. falloutboy

    falloutboy Veteran Member

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    Yes, I am fairly new at this, especially considering Qjets.
    The PO had installed a Holley DP - IIRC 4150 - and left most things unattached. It ran, but not what I would call good.
    Than years past I'm in the process of restoring it kinda original.

    And yes, I bought that carb and if I am lucky I can test it on a car that already has a Qjet and is running fine next weekend. Have to drive 2 hours to his place, but hey - no pain no gain :D
    Ordered a rebuild kit and a choke conversion online.

    But as live is, I kinda have to fix my daily driver before I can think of tinkering with the carb. And than again, maybe I should have a gas tank or fuel lines in the Camaro before I do anything else :D

    Could someone post some close up pics of how the TH350 and throttle cable are hooked up? And if possible what kind of clips etc. they are?
    Thanks in advance
     
  9. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    A bit off topic, but I remember my '72 Corvette with a Quadrajet I had two different choke rods..a "summer" rod and a "winter" rod of different lengths. I never could get a single rod to work perfectly right in both temperature extremes. The summer rod would go off choke too quick in the winter and the winter rod would stay on choke too long in the summer. I could change it out in like a minute so it was no big deal. I tried all combinations of the bimetal spring and rod lengths etc. Verified the heat riser was working and even changed that out.
     
  10. falloutboy

    falloutboy Veteran Member

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    Thankfully the camaro is not a daily driver - especially not the way it is registered right now. But good to keep in mind, and hopefully the electric conversion takes care of this issue.
     

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