ccsmith51
Well Known Member
I have a Westach dual CHT/EGT gauge. On my last couple of flights the EGT has acted sporadically. It is in the right exhaust below the connection of the two pipes. The engine runs fine. Basic troubleshooting indicates it is either a probe or a connection.
I plan on replacing the complete unit with new probes. Mainly because when I checked the instrument with boiling water the CHT read about 20? low. It has the plug ring sensor and from what I understand the bayonet sensor is more accurate, so I am changing to that.
But I was wondering about the real value of a single point EGT....
I follow the 48 rule of thumb, where about 75% power is when the combination of RPM and MP equals 48. If I am at 48 or above, I don't lean. If below, then I lean. Since I don't attempt to run LOP on a carbureted engine my leaning procedure is Lycoming standard: lean to onset of rough running, then richen to smooth.
In this case, what valuable information does the EGT provide?
I plan on replacing the complete unit with new probes. Mainly because when I checked the instrument with boiling water the CHT read about 20? low. It has the plug ring sensor and from what I understand the bayonet sensor is more accurate, so I am changing to that.
But I was wondering about the real value of a single point EGT....
I follow the 48 rule of thumb, where about 75% power is when the combination of RPM and MP equals 48. If I am at 48 or above, I don't lean. If below, then I lean. Since I don't attempt to run LOP on a carbureted engine my leaning procedure is Lycoming standard: lean to onset of rough running, then richen to smooth.
In this case, what valuable information does the EGT provide?