cummins big cam heat

Discussion in 'Owner Operators' started by roamaround, Aug 3, 2012.

  1. roamaround

    roamaround Member

    whats too hot climing a hill in 105 weather for water temp
  2. Duck

    Duck Quack Supporter

    Ain't sure what you mean by "Big Cam", .. but I just dug this up with a Google search.

    170°F - 190°F is about the average, what I usually see with an ISX motor, but they get up around 210°F or so when climbing a grade. If the truck has a fan clutch override switch, I usually set it to "ON" at the bottom of the grade or as soon as I see the temp start climbing. Otherwise it'll kick on and off every 30 seconds & put unnecessary wear & tear on the fan clutch.
  3. blackw900

    blackw900 Flatbedder For Life!

    The old "Big Cams" and pretty much any of the other "Pre Electronic" 855 block Cummins were good up to around 190 degrees, Any higher than that and you were getting pretty near the danger zone.
    The newer motors can run quite a bit hotter...My N14 runs at around 190 most of the time and the fan won't come on until it hit 210. I usually turn the fan on manually when approaching a grade just to keep it a little cooler than that.
  4. blackw900

    blackw900 Flatbedder For Life!

    I just read a post from you on another forum where you mentioned that it's been getting up to 240 degrees! You're very lucky that you didn't blow a head gasket or pull a sleeve at those temperatures.
    You need to back off the throttle when it starts getting above 190 and not let it get any hotter than 210 or therabouts or you're gonna **** that engine!
    Those older motors were good motors but they had their limitations and by running it that hot you are far exceeding those parameters.
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  5. Racer X 69

    Racer X 69 Member

    I remember my dad driving a truck with a big cam Cummins in it. When I took a turn at the wheel he had me watch the pyrometer while climbing grades, and had me shifting (been so long I can't remember if it was shift up or down) when the pyro would reach a certain temp.

    He said it was to keep from melting pistons, and it also helped the engine run cooler.

    Don't see pyrometers in trucks much anymore. Most of today's seat filling steering wheel holders wouldn't know what to do with one.
  6. blackw900

    blackw900 Flatbedder For Life!

    Mine's got a pyro....
  7. Racer X 69

    Racer X 69 Member

    Last of the Mohicans. Yours is an older truck too.

    Both of the Vulvas I drove for this company had them, one had an ISX (an '05) the other had a D12 Vulva (an '07). The 'Shaker I am in now has a Detroit ('07), and no pyro.
  8. colohayhauler

    colohayhauler Clutch Monkey

    Is it a low-flow cooling system? I heard those were a ***** when they tried them. Especially in the 444's, anything over 210 I would consider too high
  9. Pops65

    Pops65 Well-Known Member

    Drove many a old 885 Big Cam still own one in the dump truck, past 200 can loose sleeve rubber on the bottom of sleeve and dump the anti-freeze into the oil pan and good bye bearings. Depending on where pyro. lead is . most likely back side of turbo, Try and keep it under 900. Above you'll have problems sooner or later. Good trick if you have a manuel switch on radiator fan besides auto one turn it on just before you start up a hill will keep temp. down longer. After that even if you have the power to pull in higher gear shift down keep RPM's up and Manifold pressure down. Higher the manifold pressure the more heat you produce. Hope that helps.
    Last edited: Jun 22, 2015

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