Direct Fuel Injection on GA Piston Engines.

[P210driver]

matt_hooks -

By "Peak" as in LOP or ROP, I am referring to the peak EGT for each cylinder. The goal of setting the mixture either lean or rich of peak EGT is to control the combustion event so that the CHT does not exceed a reasonable value (we use 380ºF, not the 460ºF that TCM/LYC might spec), and the internal cylinder pressures remain at safe levels.

The mixture guidelines ("slightly rich of peak") are fine - IF you have a normally aspirated engine, and the power setting is less than 65-70% power. For high-power ops (both turbo and normally aspirated engines), what we really want to control is the peak pressure inside the cylinder, and running the mixture well ROP (like 150º or more cooler than peak, not the 25-50 degrees specified in the POH) will prevent the combustion pressure from exceeding safe values. Note that operating LOP (by 50ºF or more) provides the same benefit, and you get to save lots of money on your fuel bill.

You can start at www.gami.com to find out more about LOP operations.