one cylinder running colder than the rest.....

[bad1racing]

Hey guys,My brother used to work at a engine shop and I watched them run a alcohol sprint car motor on the dyno.When they were warming it up he had it running at about 1500rpm and a couple of the cylinders were running cherry red.So I said something to him and he buzzed the motor a couple of times and then set it at a different rpm and then all the pipes were the same.Like a couple of the cylinders were running a little lean at the first rpm and fattened up at the other rpm.Just an observation.

Kendall