I fly a 1965 PA-24-400.
I've been struggling with getting the EGTs even enough that I can fly efficiently. So much so that I had my A&P install GAMIs but it didn't really do anything to improve the situation.
Yesterday I went on a long flight and I spent some time collecting data (of course I left the data in the plane so I can't share it right now! But I promise to put it into a spreadsheet and share it soon). I flew along at 11,500 and wide open throttle (about 19" pretty consistently across the RPM range) and wrote down the CHTs and EGTs for various RPM and fuel flow readings. 2100-2400 RPM and 16-20 gph.
I noticed one thing that somehow i never noticed before. The even bank of cylinders (left side?) runs hotter on EGT than the odd bank (right?). (#4 somehow is less effected than the others but still hotter than the odd cylinders)
The even cylinders always peak earlier than the odds and the odds never reach peak. As a result I am not able to run at the book fuel flows for a given power setting. I always end up 1-2 gph richer.
The CHTs all seem fine. They all stay below 400F pretty much all the time. Even though you hear people say it's hard to run the IO-720 cylinders cool I never have an issue. Sometimes I struggle with Oil temp (on hot summer days in climb at lower altitudes) but CHTs are never an issue.
At recent annuals I have had to replace #2 and #6 cylinders due to sticking exhaust valves. So the data correlates with that.
What could cause one bank of cylinders to run leaner than the other?? Perhaps an induction issue?
I've been struggling with getting the EGTs even enough that I can fly efficiently. So much so that I had my A&P install GAMIs but it didn't really do anything to improve the situation.
Yesterday I went on a long flight and I spent some time collecting data (of course I left the data in the plane so I can't share it right now! But I promise to put it into a spreadsheet and share it soon). I flew along at 11,500 and wide open throttle (about 19" pretty consistently across the RPM range) and wrote down the CHTs and EGTs for various RPM and fuel flow readings. 2100-2400 RPM and 16-20 gph.
I noticed one thing that somehow i never noticed before. The even bank of cylinders (left side?) runs hotter on EGT than the odd bank (right?). (#4 somehow is less effected than the others but still hotter than the odd cylinders)
The even cylinders always peak earlier than the odds and the odds never reach peak. As a result I am not able to run at the book fuel flows for a given power setting. I always end up 1-2 gph richer.
The CHTs all seem fine. They all stay below 400F pretty much all the time. Even though you hear people say it's hard to run the IO-720 cylinders cool I never have an issue. Sometimes I struggle with Oil temp (on hot summer days in climb at lower altitudes) but CHTs are never an issue.
At recent annuals I have had to replace #2 and #6 cylinders due to sticking exhaust valves. So the data correlates with that.
What could cause one bank of cylinders to run leaner than the other?? Perhaps an induction issue?
