Leaning with an EDM 700

leadsledfan

leadsledfan

New member
Good Morning all!
I hope everyone has been flying to their hearts content!

I know the general procedures for leaning, as well as the one mag trick.
My Cruisair, with the 165 Franklin, has an EDM 700 with 6 Cylinder EGT, 6 Cylinder head temp, and oil etc..

What should I be looking for as far as EGT temps, head temps, and oil temp?
 
Temps will vary depending on how far the probes are located from the exhaust flange on the cylinder. Optimum is 3 inches any closer probes burn up fast. Lean til it stumbles notice the hottest cylinder then richen back 50 degrees. You can run carb heat and lean more but you will lose a couple of miles per hour.
 
Adam, you have the right instrument for tuning your mixture setting and monitoring engine health. What settings to use is a controversial topic and I know very little about the Franklin engine. However I found the articles by John Deakins very good reading. You might want to check out articles 63-66 at the following link:
http://www.avweb.com/news/pelican/182544-1.html
 
I think your analyzer will allow you to see which is the first cylinder to reach peak, not necessarily the hottest. The first to reach peak will go to the lean side if (as) you continue to lean.
I have a 6 cyl analyzer too, and I love it. I have always been amazed at how uniform the EGT and CHT's my cylinders run. I would have thought a carb'ed engine like our Franklins with the long run from the carb to the # 5 & 6 cylinder would not have what appears to be very uniform fuel/air mixture.
 
My instrument shows me the EGT and CHT for each cylinder. I have a "Lean Finder" button that will take me to the cylinder that is leanest (hottest) and show me it's info. I typically lean until I drop a few RPM, and slightly enrichen from there.
I typically see EGT's around 1500-1525 leaned, and CHT's around 300 leaned.
It is a wonderful instrument, and I must commend Pat Driscoll for installing it

Separately, I slightly lean during cruise climb, and I lean fairly aggressively on the ground while warming it up and waiting for clearances, I was told that this will reduce lead fowling. Any problems with this practice?
 
One of the things I always loved about Franklins besides being turbine smooth is they will pull at least one inch more manifold pressure than a continental or lycoming. I remember having a booth at Sun N Fun or Oshkosh and people saying look at that silly intake manifold. Little did they know that was part of the secret to the way the Franklins run. I actually have a couple of customers that run their 220's lean of peak and have for years and not burned anything up.
 
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