Jetting help

[Jim46]

I know this is a loaded question, how much head temperature gain will one size smaller jet give me at 100° in west TX

 

[DynoDon]

Each engine is different due to the amount of timing the engine has, and the atmospheric conditions on a given night so yes, it is a loaded question. Good instrumentation to read the evening conditions and a record book is your best option.

 

[Kart43]

No performance engines are tuned by the temp of the outer surface of the cylinder head below the spark plug. That is a random piece of information that is only applicable to that engine in a specific set of parameters. I could tune an engine to a specific temp on the dyno, and then it gets put on a moving vehicle behind a body on a bound up kart, with a driver that drags the brakes for 3/4 of a lap.