Cylinder Head Temperature survey

[Matt Clark]

Hi all. I am just curious as to what everyone else is doing & seeing for Cylinder Head Temperature.
I did a search & found these threads, but thought it'd be interesting to see more people chime in if possible.
http://www.apexspeed.com/forums/show...ht=temperature
http://www.apexspeed.com/forums/show...ht=temperature

If you could, where are you taking the temperature from (under the spark plug, under a head stud, etc) and what type of numbers you are seeing for a "properly" cooled engine. Thanks!

[DLRacing]

Ambient 86F. Under plug temp 350F aprox @ wot on a long stretch. Oil temp @ 240F. Moderate belt slip.

Ambient 62F. Under plug temp 300F aprox @ wot on a long stretch. Oil temp @ 180F. Liberal belt slip.

NOTE: Head temps crash under deceleration.

NOTE: Look for about 40 to 50 degree lessor reading for under stud verses under plug reading. Under stud reading have about twice the response time to temp change compared to under plug readings.

Borg Warner air frame mechanical gauges.

Reading taken at 5500 to 5800 rpm fourth gear.

Yes, I'm nuts.

[jahillsr]

Ambient 86F. Under plug temp 350F aprox @ wot on a long stretch. Oil temp @ 240F. Moderate belt slip.

Ambient 62F. Under plug temp 300F aprox @ wot on a long stretch. Oil temp @ 180F. Liberal belt slip.

NOTE: Head temps crash under deceleration.

NOTE: Look for about 40 to 50 degree lessor reading for under stud verses under plug reading. Under stud reading have about twice the response time to temp change compared to under plug readings.

Borg Warner air frame mechanical gauges.

Reading taken at 5500 to 5800 rpm fourth gear.

Yes, I'm nuts.

LOL. That is terrific info. I don't know how to use it yet ... but is is always good to know data. Thanks!

[Matt Clark]

Thanks Dave.
I will see how that compares to my readings once I get my CHT sensor installed.

[smsazzy]

380-400 at pretty much any ambient temp. 6500 RPM, 4th gear.

Temp under the plug. Oil temp is always 215-220 at same spot.

Varies quite a bit on the track depending on where you look. My data system logs it at 1hz, and it can vary 20+ degrees on one lap.

edit: forgot to mention, add 15 degrees if you're in a draft for the full lap.