Hello Tom,

I don't have a solution for you. I believe, however, that there may not be a problem to solve. A CHT 10 degrees hotter than the others is, in my opinion, very close. I'd be happy with that. An EGT hotter than the rest is, by itself, meaningless. A more important consideration is the consistancy of the temps. Has #3 always been 80 degrees hotter? A sudden change in relative temps can indicate plug,  ignition or injector problems. If it's always been hotter and you've noticed no "relative" change in the pattern then you're probably trying to fix a non-problem. There's no limitation on EGTs and the exact location of the probe in the pipe can make large differences in the temp indication. Even which side of a pipe's curve the probe is on can cause substantial differences in indication. If the pattern of all of the cylinders has remained about the same from day one then go fly and enjoy your good running engine.

Bill Harrelson
N5ZQ 320 1,700 hrs
N6ZQ  IV under construction





I have been chasing a problem with my EGT's and have hit a wall. My #3 EGT is about 80 degrees above the rest of the cylinders. It also has the highest CHT, but only by 10 degrees over #4. Yet #4 has one of the coolest EGT's... #2 is the first to peak while leaning.

So how many gallons did Jimmy have left in his bucket after Jane.... Just kidding. Sounded like a math quiz.

A better way to explain it, see graph below.

http://www.n54sg.com/images/egt.jpg


I have done everything I know to do and can't seem to figure it out. I have switched injectors from #4 and #3 thinking the injector may have been the problem. Didn't seem to change anything. I have done my best to check for a leak in the intake system. Couldn't find anything.

Attached is the data that goes with the graph.
It is a Superior XP-400SRE prototype so I don't exactly have anything to base my data on.

Anybody have any ideas?
Tom McNerney
www.N54SG.com