Max safe cylinder head temps at the track

Discussion in 'Drivetrain, Exhaust and Electrical' started by Nvrfinished, Jan 29, 2019.

  1. Nvrfinished

    Nvrfinished TMO Advanced

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    What is the max safe cylinder head temps that you can run for an extended time - same 20 minutes?

    My 2016 GT motor is still stock without a tune or performance adders. Running at Willow Springs this past weekend I hit CHT's in the mid to upper 240's a couple of times. Not knowing the answer to this question, I immediately slowed down and within half a lap they were back down to the high 220's/low 230's where I put the hammer down again.

    I will be adding some Trackspec louvers in the near future to replace the stock ones. The idea is to enhance aero some, but mainly to improve cooling since I have a Ford Performance Power Pack 3 sitting in the garage waiting to be installed.
     
  2. JAJ

    JAJ TMO Addict

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    The ECU won't cut power until 300, so anything up to about 270 or so is within the range that Ford thinks is ok. Engine oil temp is more important, if you have that gauge available.
     
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  3. Nvrfinished

    Nvrfinished TMO Advanced

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    OK, that's good to know then. It's much higher than I anticipated. I had 255 degrees as the danger zone rattling around in my head for some reason and is why I slowed down. No idea where I got that number. The only gauge for oil temp is the typical sight display of green, yellow, red. I've run very close to yellow many times, but it's anyone's guess as to what temp that translates to.
     
  4. OCPONY

    OCPONY TMO Intermediate

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    Are your thinking of EOT Engine oil Temp? ECU starts pulling power around 280* to 315* range.

    ECT the ECU starts protecting at 240*in first gear and range goes up to 260* limit in 6th. At least that is what is in my GT base tune. I didn't look at my GT350 base tune though but iirc they are very similar but a little higher limits in the GT350 tune.
     
  5. JAJ

    JAJ TMO Addict

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    CHT is usually a bit higher than EOT and a lot higher than ECT. You're right about the EOT range, and for engines without the sensor, EOT is computed from CHT.

    So much for the alphabet soup - I think the OP was ok at the temperatures he was running, and had about 20 or 30 degrees of headroom. It never hurts to give the motor a breather (that's what straights are for in HPDE) so he was being more cautious than necessary, but you can't fault him for that.
     
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  6. OCPONY

    OCPONY TMO Intermediate

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    EOT is computed off several variables including CHT and RPM and more probably. I know we only have a pressure sensor and no temp sensor. I check my custom oil cooler with an IR gun and have yet to see it exceed 220* after coming into the pits even with very limited cool down time. I know the IR temp reading even at the oil inlet is always lower than the temp gauge in the dash by anywhere from 20* to 35*. Mine is just Derale cooler mounted and ducted to mimic the GT350 setup. Main air flow is from the removed fog light.

    I know my Expedition blew the radiator tank out at 258* while idling. Electric fan had come unconnected.
    My 2011 GT/CS pulled power when head temps hit just over 250* once while on track...never did figure why it hit that high as it only did it once while running at Barber Motorsport.
     
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  7. Nvrfinished

    Nvrfinished TMO Advanced

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    This is all great info guys, thanks!
     

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