Cylinder Head Temps

[GT_Roadcourse_Newb]

Sorry, I did try a quick search and no luck, so I am asking the forum a very simple question...


Puttering around town, I get cylinder head temps up to 220 with ease.

What is the 'green' range for these temps, and when e.g what Temperature should I start to change driving behavior to avoid approaching the 'red' ?


The middle range of the 'dial' looks like its around 230/240. Would this still be an OK temperature to keep running hard on track?

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[steveespo]

244 CHT is limp mode for Coyote in '16. Ask me how I know.

 

[GT_Roadcourse_Newb]

Say, [MENTION=22207]steveespo[/MENTION] , how d'ya know that tidbit about 244 CHT?

Can you describe what happened? tia

 

[Brent Dalton]

Before changing to the 170 thermostat and a mostly water mixture with a bottle of water wetter, it was not uncommon to see 215-218 while driving around. The "target" temp in the computer is 212 ECT stock. I'd have to look, but I think the fans come on at 40% at 212 ECT and 100% at 223 ECT, which is about 10 degrees cooler on average than CHT. I got to 232 CHT once at COTA and backed out of it (scar tissue from driving rotaries for many years) as I'm not comfortable with those temps. They may still be ok, just too hot for me. It was significantly hotter outside when I was at Road Atlanta in June and, after the water mixture and thermostat, the highest I saw was about 220 CHT. I'm happy with that for now. It's a great time to change the coolant when the bumper is off (sorry, I know you just had it off). Drain is on the passenger side of the radiator.

 

[steveespo]

Say, [MENTION=22207]steveespo[/MENTION] , how d'ya know that tidbit about 244 CHT?

Can you describe what happened? tia

Road America, 90 degree temps, 9 laps in (about 25 minutes) of a 30 minute session and chasing Cayman GT4 Cup cars at 7700 rpm shift points, hit 244 halfway between the exit of Turn 3 and the bridge went it just went flat. Didn't see the "reduced engine power due to high temperatures" message but i'm sure it came up as I saw it one time under other circumstances. Car wouldn't o past 3000 rpm and was at limited throttle, I took the turn 5 exit off track and cooled it down for the next session. High revs is the issue, the need for additional (not replacement) oil cooling is the main reason. The engine is trying to shed a tremendous amount of frictional heat and the oil cooling jets to the pistons add alot too at RPM above 7000. My plan is to plumb a 9 series Setrab (the one from Ford's 302S kit that I have laying around) in series with the Water to Oil cooler on the car now. It is very difficult and expensive to put enough BTU capacity with a Air to Oil setup alone. I did it on my 302R build and the 35 row matrix I installed only keeps the oil at 275 under high temps/max revs/end of sessions, prior to that with the 16 row matrix and the Boss 302 water to oil I usually maxed out at 245. Hoping to pull the oil temps in the '16 down to that range and help the ECT/CHT as well. Also I have to call JDM about turning my fans on at 100% when ECT hits 200. Good point Brent.

Steve

 

[GT_Roadcourse_Newb]

Thanks for the information guys. I'm sure others will appreciate it too. AND they may understand what the heck you just said! :doh:

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