Higher capacity water pump or aluminum radiator??

Discussion in 'Small Block Tech' started by 70skylarkcusto, Sep 26, 2019.

  1. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    been having some heating issues with my 350 since it was rebuilt. Some days it will be okay, warm days the temperature slowly creeps up and up and up. Gotten up to 220 before. I’d like to not be limited by summer weather to be able to drive the car.
    What’s better to try to remedy this issue? Larger capacity water pump? Or aluminum radiator? I have a fan shroud, 7 blade clutch fan, original radiator that has been acid washed. Thermostat is 180*
     
  2. MrSony

    MrSony Well-Known Member

    sounds like an air bubble. let it run with the cap off, car jacked up so the cap is higher than the thermostat housing. have a drain pan handy and be ready to put the cap on once it starts to spill over. that will get any air bubbles out.
    that or your near 50 year old radiator just sucks.
     
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  3. alec296

    alec296 i need another buick

    hiway driving or city driving? What is your timing set at and is carb correct carb for engine?
     
  4. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    Doesn’t matter if it’s highway or city, happens regardless of where I’m driving. The temp just slowly creeps up and up, might take 25-30 minutes but once it gets past 195 it seems to just keep going.
    Ignition timing is 14 degrees btdc initial all in at 2500 for 36 degrees total. I’ve had both a q jet on there and a qft 650, doesn’t seem to make a difference what is on there. Cam is a ta-284

    I will try to burp the system as mrsony suggested
     
  5. Mark Demko

    Mark Demko Well-Known Member

    A new rad, aluminum or copper/brass might make a difference, BUT try Mr. Sony's suggestion first.
    Go thru the basics to eliminate faulty components.
    When the car is fully warmed up, turn it off, and feel all over the rad to see if its uniformly warm/hot OR if there are cooler/cold spots, if you feel a cold/cooler spot, theres a blockage.
     
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  6. 72skylarkconvt

    72skylarkconvt Well-Known Member

    I just ran through all the steps of chasing down a overheating car. The rad was the main issue but still got hot. Replaced the clutch on the cooling fan, issue solved. The clutch even seemed it was ok, but was prob slipping. I put on the new one and could feel a HUGE diff the air it was pulling.
     
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  7. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    I understand exactly where youre coming from, but my motor never had heating issues before it was rebuilt. It still has the same clutch but i have tested it and cannot confirm it is slipping.
     
  8. alec296

    alec296 i need another buick

    Its not about confirmation of it slipping, , as mentioned, the amount of air it moves. At a quick hit of throttle, it should almost blow you back from fan shroud. If it isn’t immediate but does catch up, its slipping.
     
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  9. MrSony

    MrSony Well-Known Member

    I am correct, the "duty" of the clutch depends on the pitch of your blades. Heavy duty clutches are for heavily pitched fans. Light duty, little pitch. Thermal clutches are best imo.
     
  10. Jim Nichols

    Jim Nichols Well-Known Member

    Flowkooler makes a higher volume water pump. Different pulley diameter affect impellor speed also. Do you have a shroud? I always put a 1/8" hole in thermostat flange. You didn't eliminate or plug the bypass? Open the heater valve when you burp the radiator too. Flush the cooling system?
     
  11. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    I think TA makes a high flow pump too. I do also have a shroud. And no the bypass is not plugged. The cooling system was cleaned when the engine was rebuilt 3 years ago, radiator acid washed and block hot tanked. New hoses etc
     
  12. alec296

    alec296 i need another buick

    Have coolant tested. Maybe not enough water in mix. I don’t think a higher flow pump is going to fix issue. Radiator may be plugged.
     
    Mark Demko likes this.
  13. Mark Demko

    Mark Demko Well-Known Member

    X2 water is the best coolant, try running all water and see what happens.
     
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  14. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    If I use just water I have to use Water Wetter?
     
  15. alec296

    alec296 i need another buick

    You wont want to leave water in there. Going into winter. It can freeze. Its just for testing.
     
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  16. 72skylarkconvt

    72skylarkconvt Well-Known Member

    replace the clutch, not a costly part, easy repair, and yes get a Thermal Clutch.
     
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  17. BadBrad

    BadBrad Got 4-speed?

    I don't even use a fan. :p:D
     
  18. 70skylarkcusto

    70skylarkcusto God, Country, Cars

    I will replace the clutch to see how that does, but it will be hard to tell given that the cold weather has already started to roll in. I am also opting to replace my water pump with the high flow unit. The water pump I have on there currently isnt correct for my year anyway, so why not get a higher flow unit while I'm in there :D
     
  19. Furious_styles6

    Furious_styles6 Furious_styles6

    Check your gauge. I once had an electrical gauge with a sending unit that was too short. It didn't immerse far enough into the coolant and showed that the car ran hot. Replaced it with a mechanical gauge and the temp was just fine.
     
  20. bostoncat68

    bostoncat68 Platinum Level Contributor

    Use the TA pump. Mike from TA posted a piece on why there high flow design is better... pretty impressive details.
     

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