Ok, why the smell

Discussion in '1970 - 1973 Specific' started by Citrus70, Dec 10, 2012.

  1. COPO

    COPO Veteran Member Lifetime Gold Member

    Sep 15, 1999
    Ontario, Canada
    If you can't take the smell then it's time to sell the car. I'm sure someone will buy it. Show us some pics, I need more cars.
  2. Greg73Z28

    Greg73Z28 Veteran Member Lifetime Gold Member

    Apr 14, 2009
    Joplin, Missouri
    I agree with shad van's post. There are many variables to consider here, that's why I pointed to the link that I did. It will break down what that carb should have in it as far as secondary rods primary rods and jets, or you can cross by the engine application as well. Keeping it simple, you can try to adjust the air mix screws first, as if those are too lean it can cause a stumble. If that doesn't take care of it, you will need to look at the primary rod/jet combination. This is assuming that it is a carb issue causing the problem.
  3. 71flh

    71flh Veteran Member

    Jun 1, 2010
    Nobody's asked the first questions...

    What does it smell like?
    Is there a color to the exhaust?

    Both are a bit subjective, in that my blue smoke, may be your white for example, but in reality, there are a limited number of true answers.

    If you want to know why the exhaust smells like it does, you have to figure out what you're smelling.

    It could be coolant, oil, gas, etc.

    Just saying you don't like the smell is meaningless... As others have mentioned, many of us like old car smell. What do you smell? Describe it. Sweet? Sour?

    Also, if it smells in the car while driving, is something leaking on the exhaust?
    Is the underside of the car not sealed?
    Is the trunk not sealed?
    Running open headers, or a short exhaust?
    Last edited: Dec 12, 2012
  4. Citrus70

    Citrus70 Veteran Member

    Sep 3, 2012
    SW Ohio
    My trunk floor is rusted but I have a trunk mat over it. The pans are not rusted, etc. There is no color to the exhaust when running. It is not a water burn off, not burning oil. It just smells like as old car that is not utned right. My 93 Chev truck does the same thing but not nearly as bad. I had a 75 Cj5 with a v8, it stank just the same. My brothers rebuild VW bug has the same smell to a less extext, the two 60's Tbirds I had had the same smell. My camaro is just much strong. Like many have said here I just need to have the dwell and timing rechecked then prob adjust the carb.

  5. shad_van

    shad_van Veteran Member

    Jun 15, 2012
    las vegas, NV
    After reading some of the other posts about this, I had a couple of questions. Is the engine and carburetor original to your car? And is the engine original as well?

    The numbers for a 70 SS 350 should be 7040203 & 7040213 for manual Trans and 7040204 for an automatic. It should be located on driver’s side of the carb behind the secondary linkage.

    As for the engine, the suffix code is located on a flat pad on the block behind the alternator. For an SS350 the suffix code should be CNJ or a manual, CNK for powerglide auto, CRE for turbohydromatic auto.

    Also has the engine been rebuilt or modified in anyway such as a cam swap or headers?

    The original 1970 L-48 motors had 10.25:1 compression ratios. That’s really high for today’s gas. They also had a fairly decent cam as well, and the carb was calibrated to work with this combination. If the engine was modified/rebuilt at some point in the cars history, with lower compression and a less aggressive came. The carburetor may be calibrated too rich for the current combination…

    if that is the case, I would look at getting the edelbrock Q-jet tuning kit, and talking to an expert carb tuner from the Carb Shop in Ontario California, or the guys at Cliffs High performance carbs, they should be able to point you in the right direction as far as tuning it goes.

    The Carb Shop # 909-481-5816
    Cliffs high performance #704-397-2921

    I buy all my q-jet rebuild kits from cliffs. They know their Q-Jets.
  6. Citrus70

    Citrus70 Veteran Member

    Sep 3, 2012
    SW Ohio
    My carb is from 1970, or so the code on it says it would be. I suspect it is orig to the car. the motor IS NOT. It is a mid 70's 350 with 170 Hp or so as I recall. I feel that the motor is not rebuilt. When ever my orig went south they just used the engine in it and put most all the engine parts back on it as they all date code to 1970 (exhaust mani, water pump, fan, carb) I am not sure if the heads are orig to car, I think not and the intake is not.
    My brother has been working for a chev dealer as a mech for many years, and the guy that rebuilt the carb is a chevy guy at that shop and over all for over 30 years and was a guru on that carb (qjet). They ordered the rebuild kit off the numbers on the side of the carb.
    I will mention that maybe the since the motor is not the orig 350 300 HP that the carb was on orig that it needs adjusted based on that alone?

  7. GOLF72

    GOLF72 Veteran Member

    Jan 11, 2010
    I love the muscle car odor. Gets me excited. LOL
  8. Gary S

    Gary S Administrator Lifetime Gold Member

    Apr 14, 1999
    Bismarck, North Dakota
    I don't think that tuning that 70 carb will gain you anything. What you will get is a carb that doesn't work anymore.
    When my Son was in college, he drove a 79 Caprice 305-2bbl. The 2bbl never ran right, and our best efforts didn't get it running like we wanted.
    Eventually, we pulled the 2bbl intake and carb and replaced it with a 70 quadrajet and 70 intake from a 70 L48 that I had sitting in the garage. That 305 never ran as nice and smooth as it did with the old 70 parts. Mileage improved a little over the 2bbl. The major improvement was the smoothness of idle and off idle performance. We ran it that way until the car was so totally rusted that it couldn't go any longer. The Caprice was junked and the carb and intake went back into the garage for future use.
    The quadrajet carb is almost magic. The design of it allows the engine to take what it needs and no more. Unlike the Holleys and Edelbrocks, it doesn't need to be calibrated to the engine. A factory quadrajet can perform right on any basic factory style engine with a normal cam. No tuning needed.
  9. Marks71BB

    Marks71BB Veteran Member Lifetime Gold Member

    I am also a big fan of the q-jet and they are great performers when built right.
    I've seen em go 200k miles easily and perform flawless the whole while.

    I have one on my 78 pickup I rebuilt 15 years ago when I rebuilt the motor and I have never had an issue with it.

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