A typical engine with standard injectors would have 5 other sets of identical curves all in the same relationship to one another but dissplaced left and right of the central peak EGT dotted line of the one cylinder you can read about on the instruments.
That was the way my engine was before the Gamijectors were installed...a flow rate difference (Gamispread) between the richest and leanest injectors of approx 2-3usg/hr...with the gamis it is .3usg/hr.
Now when I lean my engine all the EGTs/CHTs rise in lock step just like the graph above...and all fall LOP in lock step-like the graph above...CHT is also a direct indication of ICP an once LOP there is a direct correlation with HP.
6 cylinders acting as one.
The engine doesn't 'run rough' so I can just keep on leaning...I get the first hint of roughness at around 80F LOP EGT. Look on the above graph and see what 80F LOP EGT equates to CHT, ICP and HP wise. The HP is so low it is past the point of efficient unless you're only concerned with endurance rather than range...so I operate around 50F LOP.
Too lean?
Engines are not damaged by 'too lean' as such...they just stop running.
They can however be damaged by not being
lean enough...or
rich enough.
They are most likely to be damaged by operating as per what pilots have for decades
perceived to be 'by the book'. That is they forgot, or were not told, that 50F ROP was ONLY acceptable at 65% power and below...say 21/23...not at 23/24...at 23/24 100 ROP would be the minimum...look at the grpah above and see how ROP you need to be to make a difference.
The
reference point for
lean or rich is
peak EGT...without a reference point words like 'too lean' are meaningless.
Now think about those Chieftains being operated leaned at climb power...think about 1 or 2 injectors being at the low end of the acceptable range of flow rate...that cylinder would be a lot leaner than the others so that cylinder would be developing much higher CHT and ICP...and with 38in MP (LOTS of air) all that fuel would be quite capable of producing
LOTS of CHT/ICP...and without an all cylinder monitor you haven't the first fecking clue.
Enough CHT/ICP can cause pre ignition all by itself...without a busted helicoil or lead fouling to provide a glowplug like effect for the next charge of fuel and air through the inlet valve...like a diesel it just explodes earlier than it should...very, VERY bad news for the piston/crankshaft/Cylinder head...and pilot
