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390 overheating problem

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by gt 500 736, May 2, 2009.

  1. May 2, 2009 #1
    gt 500 736

    gt 500 736 Member

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    I have a 390 engine.
    To try and make a long story short my engine was bored 30 over and it ran fine, after Katrina we bored it another 30 over due to the fact that the car went under water.
    Now at idle I run at about 185-190, but when driving it runs up to about
    245.
    I have electric fans and a 180 thermostat and it will belch out the cap and
    smells hot.
    When there is no thermostat and a clutch fan it runs longer before it overheats , but it does not boil over into the resivoir and it does not belch out of the cap.
    Some people say that 60 over is too much and it getting to hot around the cylinder walls and others say it is nothing to worry about and there is a restriction somewhere.
    The radiator is new, as is the water pump.
    The radiator was flow checked and was fine and the water pump looks like a water fall.
    The head gasket tabs appear to be in the correct places and I have to feel that the intake gaskets are correct.
    Does anyone have any suggestions.
     
    gt 500 736, May 2, 2009
    gt 500 736, May 2, 2009
    #1
  2. May 2, 2009 #2
    Bob Gaines

    Bob Gaines Well-Known Member

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    The short answer is start over. This issue has come up before so your not alone. I have had many of these engines over the years and it has been my experience even 30 over can cause over heating. 60 over is the kiss of death. 390 blocks are plentiful relatively speaking but on the 428 engines rather then over boring I sleeve all 8 cylinders so as to keep it standard . I wouldn't go to that trouble or expense on a 390 block because they are more accessible. I have never had a over heating problems once it has been sleeved back standard. It is cheep insurance when you consider pulling engines and redoing a block. I know you are past that point I am sorry to say. I think you are going to be chasing your tail trying to find another reason for the over heating. I hope I am wrong for your sake but I don't think so. The best of luck with solving your problem . Bob G.
     
    Bob Gaines, May 2, 2009
    Bob Gaines, May 2, 2009
    #2
  3. May 2, 2009 #3
    rsimkins

    rsimkins Well-Known Member

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    gt 500 736,

    I've got to agree with Bob on this one. .060 is just too much. I'd try to stay away from even .030. Try to find a good replacement that you can keep standard.
     
    rsimkins, May 2, 2009
    rsimkins, May 2, 2009
    #3
  4. May 2, 2009 #4
    thefordshow

    thefordshow Well-Known Member

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    Bob's on the money with his assessment. [lots of 390 cores out there in much better shape than 30-60 over]
     
    thefordshow, May 2, 2009
    thefordshow, May 2, 2009
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  5. May 2, 2009 #5
    gt 500 736

    gt 500 736 Member

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    Thanks for the help, I have been receiving so much advice that my head is spinning.
    I have dipped e-coated painted and sent this beast to Canada for reassembly and was so happy to drive it.
    It runs like a dream, better than before but I guess it is time to cut her heart
    back out and transplant with a new one.
     

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    gt 500 736, May 2, 2009
    gt 500 736, May 2, 2009
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  6. May 3, 2009 #6
    thefordshow

    thefordshow Well-Known Member

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    If you don't mind me asking, who did the re-assembly in Canada? I remember being shown a photo of a blue 68 shelby after katrina, it was on a hoist, up as high as it could go to help keep it out of the water.
     
    thefordshow, May 3, 2009
    thefordshow, May 3, 2009
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  7. May 3, 2009 #7
    gt 500 736

    gt 500 736 Member

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    Peter Fall did the assembly in London,Ontario.
    I was just finishing it up after 28 years of ownership and we were trying to get it ready for Crusing the Coast in Biloxi,Ms. for the October cruise.
    It did not make it.
    We were not able to get it out till October when we got permission to go in.
    Pete tracked me down to see how we made out, my reply was short and sweet.
    Lost three houses in Lakeview in 13 feet of water and the car is in Chalmette
    under 20 feet of water.
    Pete did a great job and the paint from my local body shop is very eye catching, now I have to just get the engine problem solved.
     
    gt 500 736, May 3, 2009
    gt 500 736, May 3, 2009
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  8. May 3, 2009 #8
    thefordshow

    thefordshow Well-Known Member

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    Peter is a good friend, makes the 68 shelby consoles. Good to hear it made it back to life:thumbsup:. best of luck, Chris
     
    thefordshow, May 3, 2009
    thefordshow, May 3, 2009
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  9. May 3, 2009 #9
    gt 500 736

    gt 500 736 Member

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    Hey, you are right he is a great friend and really came through for me
    when I did not think I could get any lower after Katrina.
    Now he is helping find a short block.
    I hate to break up all his beautiful work especially in that engine compartment.
     
    gt 500 736, May 3, 2009
    gt 500 736, May 3, 2009
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  10. May 6, 2009 #10
    snakeman

    snakeman Well-Known Member

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    2 other possibilities to consider (1) if timing is advanced too much can cause it to run hot some but not to 245 degrees. At that temperature (2) you could possibly have a head gasket leak causing the exhaust gases to superheat your coolant. Years ago they did not have this technology I spent a lot of money replacing everything on thar car before bringing it to a mechanic friend of mine, I could not believe it !! today they make a checker to check for exhaust gases in your coolant system ,check with some of your more technical automotive shops to have this checked. Hopefully this will check out and save you a lot of money. Snakeman
     
    snakeman, May 6, 2009
    snakeman, May 6, 2009
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  11. May 7, 2009 #11
    TLEA

    TLEA Well-Known Member

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    One of the other curses of modern times is unleaded fuel. Lead would actually help to cool the combustion (another reason why it was bad for emmissions) That combined with a .060 can spell disaster.
     
    TLEA, May 7, 2009
    TLEA, May 7, 2009
    #11
  12. May 7, 2009 #12
    gt 500 736

    gt 500 736 Member

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    Hey I have checked the timing and I am where I need to be and I also brought home from work a block tester to for exhaust gas and it checked ok.
    I manage a service department for a Chrysler dealership and I talked to my local zone tech who cut his teeth on FE engines and he said to call Griffin Rads and talk to them.
    I have since ordered a rad from them.
    They say they have seen this before and their rad should fix the problem.
    got my fingers crossed.
     
    gt 500 736, May 7, 2009
    gt 500 736, May 7, 2009
    #12
  13. May 16, 2009 #13
    DeLa1Rob

    DeLa1Rob Well-Known Member

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    Please post your findings after you swap radiators.

    robin
     
    DeLa1Rob, May 16, 2009
    DeLa1Rob, May 16, 2009
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