Different Radiator Diameter?

Discussion in 'Engine Topic' started by ratpatrol71z28, Mar 31, 2016.

  1. ratpatrol71z28

    ratpatrol71z28 Veteran Member

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    Hey guys, I'm working on a 1978 with a sbc 350 with A/C. It originally had a 3 row in it.... after testing it I found a few leaks so it is no good. I have two spare radiators both identical to the other radiator that was in the 78, the only problem is the upper inlet is smaller in diameter than the other radiator. So basically the upper hose is too lose and won't fit in tightly. :screwup:
    Why are they different than each other? If I can adapt it to work, will I have any problems or should it work like any other normal radiator?
     
  2. Damon

    Damon Veteran Member

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    It came from a different application. Small differences in inlet and outlet diameter make very little difference is how the radiator will perform- they aren't the restriction point.
     
  3. ratpatrol71z28

    ratpatrol71z28 Veteran Member

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    Thank you, today I installed the radiator and found a hose that fits both the normal water neck and smaller inlet! After running it today I found a problem as the radiator seems to overflow itself. I believe the thermostat isnt opening. Could it be clogged?
     
  4. Camaro75LT

    Camaro75LT Masshole Staff Member Lifetime Gold Member

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    Define over flow itself. With the radiator cap on and the overflow bottle connected, it's normal for a little coolant to escape into the overflow.
    Is the car overheating? Did you get all air out of the system?
     
  5. slayer021175666

    slayer021175666 Veteran Member

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    Test the thermo by putting it in a pan of water on your kitchen stove with an instant read thermometer. Note when the thermo opens (at what degree). Or, just replace the thermo and call it good. There is no "restiction" just because the fitting is a little smaller. Water will flow through either, just fine.
     
  6. ratpatrol71z28

    ratpatrol71z28 Veteran Member

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    I replaced the old thermostat with a new one.... When i say overflow, i mean when the cap is off and the water is gurgling out of the cap end after the car has been running for a few minutes and i build up the rpms.... I dont believe i have gotten a the air out of the system yet....
     
  7. Camaro75LT

    Camaro75LT Masshole Staff Member Lifetime Gold Member

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    If it's not too much work, pull the thermostat back out and drill an 1/8" hole on the outer edge as seen here

    [​IMG]

    That will allow trapped air to escape. Why are your running the car with the radiator cap off? I wouldn't worry about coolant splashing out without the cap on. If the car isn't overheating, gets up to temperature fairly quickly and isn't leaking,you don't have any problems.

    Edit: I reread your last post. When you increase rpm, the coolant in the radiator will drop down some. When the engine goes back to idle, the coolant rises in the radiator. "Splashing" is perfectly normal.
     
    Last edited: Apr 2, 2016
  8. ratpatrol71z28

    ratpatrol71z28 Veteran Member

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    Alright, ill drill the hole to make sure the air escapes. I had the cap off because I pulled the old 20 year old rotted radiator out and put in another, after filling it up with water I know it would need some more after the system releases all the air bubbles. I need to clean the system so i am going to try some CLR is that a bad idea? I have read alot of people with successful attempts with it.
     
  9. Camaro75LT

    Camaro75LT Masshole Staff Member Lifetime Gold Member

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    I've heard people using clr, vinegar and dish soap. While I'm sure they all work, I'd be worried about gasket damage (head gasket, water pump, etc). In your shoes, I would disassemble the cooling system and clean it by hand. The waterpump only takes twenty minutes to remove. Take the radiator hoses off and clean everything with degreaser and a garden hose.
    You can flush the heater core with a garden hose as well.

    There are plugs on the side of the engine block that can be removed and flushed out. Essentially, you should be able to clean everything without rough detergents.
     
  10. ratpatrol71z28

    ratpatrol71z28 Veteran Member

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    Alrighty, yesterday I have found a leak from the waterpump so it will be getting a new one soon.... could the bad waterpump also be another reason of why the water wasn't circulating up into the upper hose?

    When running the car for the short period of time there seemed to be a lot of what it appeared to be steam.... Now as I am thinking it also has bad freeze plugs due to the entire cooling system being neglected. That would make sense of where the steam is coming from, right?
    If it was a blown headgasket, the engine oil would be contaminated???
     

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