Restrictor instead of thermostat?

Discussion in 'Race 400/430/455' started by BUICKRAT, Apr 2, 2019.

  1. TORQUED455

    TORQUED455 Well-Known Member

    On a 600HP street BBB, I use a cheapo AL/Plastic radiator from a 90’s GM vehicle, 160 stat, cheapo parts store water pump, locked timing @ 34, 250 cam, LT1 starter, no start retard, 11:1 cr, stock fan, clutch and shroud and drive the car on the street with no overheating or even “temp creep” in traffic.

    If you are heating up in traffic, the most likely culprit is not enough airflow through the radiator. Is the fan clutch working properly? Does the temp drop back down when you get on the highway?

    You may want to double check your fan clutch, drop your stat temp to 160, and lock your timing.
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  2. DasRottweiler

    DasRottweiler -BuickAddict-

    Reference pics :
    2019-04-06 15.27.08.jpg 2019-04-06 15.27.40.jpg 2019-04-06 15.28.09.jpg
    Hope this helps .....Jim
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  3. buicksstage1

    buicksstage1 Well-Known Member

    Ok, so the pulleys I listed above are for a long pump. I wonder if anyone has made a list of all the different pulleys for the 2 different pumps? In 71 there is a single groove small ID WP pulley that is for the short pump but they are hard to find.
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  4. DasRottweiler

    DasRottweiler -BuickAddict-

    Pulley numbers:

    2019-04-07 10.22.14.png
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    BUICKRAT Torque Rules!

    Thanks a million guys! I'm going to try the 1238156 pully. Jay also dropped off couple bigger crank pulleys for me to try.

    Bob, Jay looked at my car and thinks my fan is too far into my shroud. I'm going to check that tomorrow when I get back to the shop. The old duck that owned this car before me, when it had the 350-2, had put a piece of window screen about 8 inches in front of the radiator to protect it from rocks etc. I left it there because it keeps my nice 700 dollar radiator clean, bug and rock free. I sometimes wonder if it could be causing an issue.
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

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  7. TORQUED455

    TORQUED455 Well-Known Member

    Get rid of the window screen!
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    BUICKRAT Torque Rules!

  9. 87GN_70GS

    87GN_70GS Well-Known Member

    With a big cam like that, most of the exhaust heat goes out the tailpipe and not into the block bc the exh valve opens earlier, letting the heat out, making it easier to cool, another side benefit of a big cam

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