Brief Description: Exhaust Gas Temperature probes 1
I installed the exhaust gas temperature probes. Directions say to go by Lycoming's recommendation but I couldn't find one. There was a note in Van's plan that says mount them 2 - 5 inches from flange but wasn't very specific. So I called Vetterman's since this is his exhaust system.
He was a great guy to talk to. He told me explicitly to mount them 2 inches from the flange. because there is already 1/4 inch taken up by the flange and 2.5 inches is ideal so 2.25 from the flange would be okay to. He also told me it is VERY important to make them all the same distance to within 1/16th of an inch. He said 1/16th inche difference will yield a 100 F degree difference in reading. He also told me to use a cut tie wrap to measure. And most importantly he told me which way to point them for each exhaust. Basically you avoid interference with the spareplug access.
#1 points forward. Points mean the hot end forward and the wire trailing end rearward. #3 is 45 degrees facing rearward to avoid interference with spark plug #2 is 45 degres facing forward to avoid interference with spark plug #4 pints straight back