Jet-A: spot on re your comments on the instrumentation and matched injectors that usually go with LOP. They mean you can actually know that you’re there. Turbo or normally aspirated – doesn’t make a difference, and Deakin explains why. How the fuel and the air gets mixed makes no difference to the performance/temperature/lean curves.
The funny thing is that just as a single, inaccurate egt gauge won’t tell us whether all of the cylinders are running LOP, it won’t tell us whether all of them are running ROP either! As Deakin shows, the ‘spread’ of fuel flows and corresponding EGTs can be very large across cylinders. Consequently and ironically, those who diligently tweak that egt gauge ROP might not have all cylinders there.
The old POHs should not say “LOP operations are not recommended”. They should say “There are some very good ways of getting your engine to run at its best, but we haven’t fitted the instruments for you to know if you are. Consequently, we’d like to hedge our risk by getting you to use that cheap AVGAS stuff to keep our cylinders cool – thanks.”
Nomorecatering’s links are in my view essential reading for anyone who runs squash bang engines.