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322 nailhead runs hot

Discussion in 'The Hokey Ass Message Board' started by XWYNNSGUY, Jul 12, 2009.

    Joined: Dec 7, 2008
    Posts: 103


    hi, have 322 nailhead in my 32 that the temp leeps creeping up at highway speeds. fine around town. new rad, new stant superstat 180. all blead. just seams like the coolant is not flowing? has anyone run into anything like this? any help or suggestions would be appreciated.
  2. Tom.......Do you know what water pump you have, A/C or non A/C ?.............seems like the A/C pump, pumps too much water not giving it time to cool in the radiator. The non A/C pump has 3 inpellers and pumps much slower............Just a thought.
    I live in Warren.........

    Last edited: Jul 12, 2009
    Joined: Dec 7, 2008
    Posts: 103


    thanks for your help! have 3 impeller pump, it just seams like it builds alot of pressure. have 20lb. cap. i just get nervouse when it creeps up around 200, maybe its just me. thanks, tom
  4. Chris Casny
    Joined: Mar 13, 2006
    Posts: 4,874

    Chris Casny

    You need a 7lbs cap, 20lbs is too high.

  5. R Pope
    Joined: Jan 23, 2006
    Posts: 3,309

    R Pope

    If it doesn't go above 200, I wouldn't worry about it.
    One thing, since it's all right at low speeds, is the carb leaning out at cruise, or the vacuum advance not working? Lean mixture or retarded spark will bothy cause overheating.
  6. DualQuad55
    Joined: Mar 5, 2005
    Posts: 1,377

    from Epsom, NH

    200 isn't bad if ambient temp is 90* or more. Infact, most modern cars run there most of the time.
    I don't get at all concerned until it creeps past 200 towards 210. psi cap will keep the coolant from boiling at a higher temp than a 7psi cap will, but If you are running hot enough to need the 20psi cap, you would want to lower the running temp.

    If the car stays at about 200 once it gets there-and doesn't creep up, you can try a 160 t-stat. This will keep the car a little cooler a little longer. On a long trip it will still eventually creepo up to 200, but will give you a bit more time for shorter trips.
  7. I was thinking the same thing about the water going to fast through the radiator, you could put a restrictor in the water line. OR!!! it may be getting lean when running down the road !! How hard is it to pull a plug when it shows you it is getting warm ??? If plug shows really really clean when you pull it - up your main jet a little
  8. Da Tinman
    Joined: Dec 29, 2005
    Posts: 4,227

    Da Tinman

    what kind of fan and shroud??? is the shroud vented?
    Joined: Dec 7, 2008
    Posts: 103


    tried the 7lb. cap and she pushed out some coolant and is staying below200. thank you and for all that responded!! this sight and members are the bomb!!
  10. if under hood air can't escape then there is less air flowing through the rad do you run a hood and side panels
    Joined: Dec 7, 2008
    Posts: 103


    hi, most of the time i do. it is off right now. the lower pres. cap seemed to help. thanks, tom
  12. How does it do idling in traffic or very slow speeds?

    If it does OK at slow speeds and idling, but heats at highway speeds, (when cylinder pressures are higher) I would suspect possibly a slight compression leak into the water jacket. There is a simple and fairly cheap test for this that involves adding a chemical (available at auto parts stores) to a radiator water sample. It will change color if there is any presense of combustion by-products in the water. At least, this fairly simple test will rule out a fairly serious problem.

    Also, do you have a radiator shroud around the fan? Some shrouds will cool OK at low speeds with the fan on, but are too restrictive at highway speeds. A fairly strong rule of thumb is that the shroud opening area in sq. inches, (hole where the fan is) needs to be a MINIMUM of 70% of the total radiator area. You will notice that some new cars have rubber 'shroud flaps' that open at highway speed and are sucked closed by the fan at low speeds.

  13. AkaOlSkool
    Joined: Feb 15, 2009
    Posts: 257

    from CC Indiana

    depending on your axle ratio and tire size = engine rpm your water pump may be spinning to fast which is why it overheats at hwy speed then cools at slow speeds. try finding a larger water pump pulley or a smaller crank pulley. this will slow your water pump which will allow the coolant to stay in the rad longer to cool it more. also a water pump spinning to fast can cause cavitation in the pump. this will stop coolant flow near complete. also if you havent tried it theres a additive called water wetter. helps remove air from your coolant which is what causes the steam. giving you overheating.
  14. TP
    Joined: Dec 13, 2001
    Posts: 2,023

    from conroe tx

    When I first rebuilt the 401 in my 59 I had over heating problems. It was retarded timing causing my problem.

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