Here's a little something I found in "Hot Rod" about exhaust.
"During the combustion process, the leading-edge flame-front
temperatures may approach or exceed 2,500 degrees F, while exhaust gas
temperatures measured in the header primary tube register 1,300-1,600
degrees F. Though many factors impact exhaust gas temperatures (EGT), flame
speed and compression ratio are the dominant ones. As compression ratio
diminishes, flame travel slows down and creates higher EGT readings. This
occurs because the flame burns during blowdown and exits from the exhaust
valve. Likewise, when ignition timing is retarded, the EGT increases."
So I have two questions: For racing is there one EGT reading to indicate
the correct A/F ratio? Cause it looks like compression and timing will
change the reading, but how much? And how far from the cylinder head should
the probe be placed?
John Beckett, LSR #79, E/FCC
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