Cooling issues, water pump question

Discussion in 'Troubleshooting & Diagnosis' started by brewquest, Sep 14, 2017.

  1. Joekool

    Joekool Veteran Member

    5,829
    14
    Feb 4, 2002
    Hollister CA USA
    Chevys hold a lot of coolant, you don't need a lot of coolant flow to cool a SBC engine at idle. You do need air flow though, the more the better.

    The boiling point of gasoline is around 180*f btw, that means the fuel is at 180*f which would mean the carb or fuel line is getting much hotter. Typically a hot cooling system (one well over 200*f) isnt going to cause vapor lock, usually its an exhaust system problem or fuel is coming very close to a head or block and heating up.

    If you have a thermo gun, check your exhaust system for restrictions (they show up as hot spots). Just a wild idea, I've seen plenty of restricted exhaust systems cause over heating problems.

    At this point, throwing parts is getting you nowhere, you need to think outside of the box....
     
  2. brewquest

    brewquest Member

    40
    0
    Jul 19, 2012
    Denver, Colorado
    Thanks, checked the exhaust. No issues found...

    I guess I was going by water's boiling point.

    I'm not sure of the calculation for gasoline, boyles law... 35gph, under 6psi at 5280ft altitude with 87 octane. The quickest way to get an answer on the internet is to wait for someone to prove you wrong...
     
  3. Joekool

    Joekool Veteran Member

    5,829
    14
    Feb 4, 2002
    Hollister CA USA
    The carb isn't under pressure, only from the pump outlet to the needle/seat is ever under pressure. The bowls are vented to atmosphere and the line from tank to the pump might even see a slight vacuum if the pump is strong enough.
     
  4. budro6968

    budro6968 Veteran Member

    1,219
    124
    Apr 2, 2016
    Jax Florida
    Have you checked yet? Can you put your hand on the rad or the Rocker cover. How long before ouch.
     
  5. brewquest

    brewquest Member

    40
    0
    Jul 19, 2012
    Denver, Colorado
    Yes, Ive checked. It is about what the sending unit says.

    A little hotter at the block, by the headers. About 3-4 seconds to ouch on the covers.

    Since I wrapped the headers and put the extra push fan in its been below 210* and running better but Id like to get her down to around 190 or below.
     
  6. NorCal_71

    NorCal_71 Veteran Member

    366
    0
    Jul 7, 2008
    Santa Rosa, CA
    What kind of electric fans are you using?
    The generic type fans do not pull much air through the radiator. I had cooling issues until I switched from a generic electric fan to a taurus 2 speed fan. This solved my cooling problems and I still have not even hooked up the high speed. It pulls a ton of air through the radiator to keep temperatures down!
     
  7. brewquest

    brewquest Member

    40
    0
    Jul 19, 2012
    Denver, Colorado
    I am using a doorman 18in and another pusher (not sure of the type) fan with a decent shroud. About 90 percent of my radiator is covered. They pull about 60a on startup and ~23a while running. Air flow is not my issue as the temp stays the same while stopped in traffic and even drops 1-2 degrees. The temp climbs while the engine is under load. For example on the highway at 3500 rpms when I go up a hill it'll climb about 4 degrees on a 90 degree day.

    Update on the pulleys:
    Changing them did increase flow but it showed little temp changes. Still running about 212-220.

    Im going to pull the motor and start checking for corrosion and gunk in the water jackets.
     
  8. dailycruiser81

    dailycruiser81 Veteran Member

    180
    10
    May 19, 2013
    ft lauderdale
    How long have you had the water pump on their? Have you done a combustion check for gases entering cooling system? I had a lot of overheating issues and chased my tail. Now I'm at about 174
     

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