Welcome to Club Hot Rod!  The premier site for everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more. 

  •  » Members from all over the US and the world!
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and hundreds of thousands of posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

 
Like Tree29Likes

Thread: SBC 350 running hot with AC on
          
   
   

Reply To Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 18
  1. #1
    Ricks72 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2018
    Location
    Boise
    Posts
    8

    SBC 350 running hot with AC on

     



    I have a 72 C10 with a SBC 350 (290 HP) running vintage air, FI tech fuel injection, 3 core aluminum radiator with full shroud and 2 ~12” electric fans. I also have a flowcool high volume/flow water pump and hi performance 160 degree thermostat. AND i also installed a spring in the lower radiator hose for good measure. All parts have less than 3500 miles on them. Timing is 15 BTDC and AF mixture is set with a target of 13:1.

    Regardless of ambient temp, the truck runs at about ~175 degrees +/- 10 degrees at idle or at highway speeds. As soon as I turn on the ac, i can watch the temp gauge go up to 210+ and pegged siting at idle yesterday with the ambient temp at 80 degrees.
    Looking for some advice or feedback that may be causing the temp to go off the charts with AC on. Thanks in advance.

  2. #2
    shine's Avatar
    shine is offline CHR Member Visit my Photo Gallery
    Join Date
    Nov 2003
    Location
    bluff dale texas
    Car Year, Make, Model: 47 inderweed
    Posts
    1,922

    12 in fans are useless . use a mechanical or get a Flex-A-Lite Syclone S-Blade Electric Fans 398 . i have used this fan on at least 12 builds . never used a shroud either .
    condenser is adding heat with air on . make sure you have 3/8 to 1/2 in of space between condenser and radiator .
    make sure your temp readings are correct. never rely on a gauge . verify first with a thermal gun .
    Last edited by shine; 08-26-2018 at 08:22 AM.

  3. #3
    Ricks72 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2018
    Location
    Boise
    Posts
    8

    Thanks for the info. Small correction, I am using 2 ea 14” elec fans. I’ve confirmed the temp with a thermal gun and the FItech handheld has a temp reading as well that’s within 5 degrees. Curious, What’s the purpose for the space between the condenser and radiator. Also, I use the shroud after doing research saying that the fan mounted directly to the radiator only covers ~65% of the radiator which in turns only cools 65% of the coolant in the radiator. Made sense at the time. Thanks !

  4. #4
    jerry clayton's Avatar
    jerry clayton is online now CHR Member Visit my Photo Gallery
    Join Date
    Feb 2006
    Location
    Bartlett
    Posts
    6,776

    Whats the amps draw of your fans????????

  5. #5
    techinspector1's Avatar
    techinspector1 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2003
    Location
    Zephyrhills, Florida, USA
    Car Year, Make, Model: '32 Henway
    Posts
    12,431

    Why are you using a 160 degree thermostat? Thermostats do not control the heat in the radiator. They simply allow water to move from the motor to the radiator at a pre-determined temperature and 160 is far too cold for a motor to run. I always ran my stuff at 190/195 and never had a problem. Of course, I never used a fosdick electric fan system either.

    .
    Last edited by techinspector1; 08-26-2018 at 07:23 PM.
    PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.

  6. #6
    firebird77clone's Avatar
    firebird77clone is offline CHR Member Visit my Photo Gallery
    Join Date
    Sep 2005
    Location
    Hamilton
    Car Year, Make, Model: 69 nomad, 73 charger, 74 vega
    Posts
    3,575

    Get a 190* Tstat so your engine will run cleaner.

    The over heating indicates inefficiency in heat removal. Mechanical fans often fix electric fan inefficiency.

    If it's easier, you can try an oil cooler with a thermostatic bypass. The bypass is for the cold months. You can pull a lot of heat out from the oil.
    glennsexton likes this.
    .
    Education is expensive. Keep that in mind, and you'll never be terribly upset when a project goes awry.
    EG

  7. #7
    NTFDAY's Avatar
    NTFDAY is online now CHR Member Visit my Photo Gallery
    Join Date
    Aug 2003
    Location
    Springfield
    Car Year, Make, Model: '66 Mustang, 76 Corvette
    Posts
    4,810

    Funny, Chevrolet didn't have any problems in 72 running all stock components except for EFI. I don't understand why people keep trying to reinvent the wheel.
    cffisher likes this.
    Ken Thomas
    NoT FaDe AwaY and the music didn't die
    The simplest road is usually the last one sought
    Wild Willie & AA/FA's The greatest show in drag racing

  8. #8
    shine's Avatar
    shine is offline CHR Member Visit my Photo Gallery
    Join Date
    Nov 2003
    Location
    bluff dale texas
    Car Year, Make, Model: 47 inderweed
    Posts
    1,922

    high flow water pump = water moving too fast though system. loose it .
    160 thermostat = wide open system water moving too fast through system . switch to 180 .
    1 16 inch fan will move air better than 2 14's . if possible run a 16 in summit oem replacement 5 blade mechanical fan .
    Rrumbler likes this.

  9. #9
    Ricks72 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2018
    Location
    Boise
    Posts
    8

    In ran a 190 when i initially did the motor install. Ran around 220 degrees in the fall last year. I know there are different schools of thought but I was concerned running that hot for extended period of time may be an (expensive) issue longer term. After the weather started to warn up, it was running hotter and then with the AC issue, i attempted to run the 160. Not sure what a fosdick fan is so can not comment on it.

  10. #10
    Ricks72 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2018
    Location
    Boise
    Posts
    8

    The water high flow pump was recently put on and overall, help my initial heating problem. I’m definitely leaning towards an airflow isse. I have a new mechanical 5 blade fan i ordered from summit a year ago and should be an easy install. I’ll give it a shot. Thanks and state tuned.
    glennsexton likes this.

  11. #11
    Ricks72 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2018
    Location
    Boise
    Posts
    8

    My error. Maybe i’m On the wrong forum? I thought this was a hot rodding site.

    Definition:
    hot rod
    ˈhät ˌräd/Submit
    verb
    gerund or present participle: hot-rodding
    1.
    drive a hot rod.
    2.
    modify (a vehicle or other device) to make it faster or more powerful.

  12. #12
    Ricks72 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2018
    Location
    Boise
    Posts
    8

    I believe it’s 20 amps.

  13. #13
    jerry clayton's Avatar
    jerry clayton is online now CHR Member Visit my Photo Gallery
    Join Date
    Feb 2006
    Location
    Bartlett
    Posts
    6,776

    Amp rating on electric fans pretty much tell the story------------if the fans are only 20 amps-they are probably slowing down the air flow sorta like a windmilling propellar on an airplane----------
    NTFDAY and Ricks72 like this.

  14. #14
    40FordDeluxe's Avatar
    40FordDeluxe is offline CHR Member Visit my Photo Gallery
    Join Date
    Apr 2011
    Location
    Prairie City
    Car Year, Make, Model: 40 Ford Deluxe, 68 Corvette, 72&76 K30
    Posts
    6,634
    Blog Entries
    1

    Quote Originally Posted by Ricks72 View Post
    The water high flow pump was recently put on and overall, help my initial heating problem. I’m definitely leaning towards an airflow isse. I have a new mechanical 5 blade fan i ordered from summit a year ago and should be an easy install. I’ll give it a shot. Thanks and state tuned.
    If you do go to a mechanical fan, make sure to run a shroud and a clutch type is what I'd go with. A stock clutch fan for your truck should do the trick. I run a 4 core BBC copper radiator in my 72 K30 and have a 180* thermostat in my engine. Mine runs around 193* in the summer. I don't even have a fan shroud on it yet.

    Your condenser should be in front of the radiator support and the radiator is behind it. The stock condensers had the core set ahead about an inch but the mounts bolted flat on the support. It might be worth spacing your condenser forward a bit to see if it helps.
    NTFDAY and Ricks72 like this.
    Ryan
    1940 Ford Deluxe Tudor 354 Hemi 46RH Electric Blue w/multi-color flames, Ford 9" Residing in multiple pieces
    1968 Corvette Coupe 5.9 Cummins Drag Car 11.43@130mph No stall leaving the line with 1250 rpm's and poor 2.2 60'
    1972 Chevy K30 Longhorn P-pumped 24v Compound Turbos 47RH Just another money pit
    1971 Camaro RS 5.3 BTR Stage 3 cam, SuperT10
    Tire Sizes

  15. #15
    shine's Avatar
    shine is offline CHR Member Visit my Photo Gallery
    Join Date
    Nov 2003
    Location
    bluff dale texas
    Car Year, Make, Model: 47 inderweed
    Posts
    1,922

    i have ran the exact same setup on at least 10 builds . never any heat problems and believe me it would show up here in texas .
    Attached Images
    Ricks72 likes this.

Reply To Thread
Page 1 of 2 1 2 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink