exhaust temps

[liltazz]

anyone know what the exhaust temp for a 400ex should be. i hear pro engine builders use exhaust temps for jetting instead of cheaking the plug. i thank you for your help.

Unless you've got all the equip. exp, time, and a way to load the engine in a static enviro. for a baseline, just use your leg!

Actually, yes it is a very good tool, but just a tool--- many things determine the exhaust temp other than jetting. ie: load, air temp, barimetric pressure, heat transfer through piston, cylinder wall, head, valves, Heat transfer to external air, etc. High budget race teams start on a dyno and if possible down load during race type conditions through computer telemetry. Most of the time EGT is just a baseline to watch for problems, actual jetting usually varies from ideal EGT numbers anyway. Race teams always look at plugs also!:D

[Chef]

yes, race teams do look at spark plugs as well....most teams in the upper ranks of NASCAR (as in NCTS, BGN, and WC) have a guy that pretty much specializes in reading spark plugs, most likely one of the truck drivers and/or the fuel man, like one of my good friends, who drives for a Busch Grand National team, he is Greg Biffle, #60 Grainger car. we are going to glamis with him and his brother and some other people. he has a tight shee

[bsr]

You can look at the spark plug to see if your running to lean or rich. I'm no sure about the exaust, as long as its not red hot you should'nt be running to lean.