My gibberish is based on operating large bore aircraft engines. Obviously an aircraft has a different load profile, WOT, pretty much constant load and cruise altitude before leaning begins. In aircraft operations EGT and CHT is monitored on all 6 cylinders, the better monitors have a lean assist function which helps you identify which cylinder gets there first. There are two schools of thought regarding leaning, the old way which is rich of peak, and the new way, lean of peak. If you follow the old school method rule of thumb, it's always rich of peak EGT, this results in maximum power, go fast, at the expense of plug fouling and poor fuel economy. If you are looking for maximum fuel economy (Avgas averages about $6/gal) then lean of peak operation is the way to go. Basically go fast or go far. There are other variables to consider as well, percentage of power being produced determines the rich of peak or lean of peak EGT value. If we're cruising along making less than 65% power, there is no danger zone for EGTs and cylinder pressures produced. However if we're still capable of making 80% power at WOT, then EGTs between 200 F rich of peak and 60 F lean of peak are verbotten Either method works, the idea is avoiding peak cylinder pressures and the possibility of blowing jugs off the crankcase, which is not a good thing since you can't simply pull over when the engine grenades.paul burke wrote:Good & Tight wrote:Duke wrote:I've said it before....saying it again. The M30 is not a good design for Forced Induction.
This is one of the reasons why boost over 13 psi on a M30 won't last.Duke were you high when you wrote this?
I'm hallucinating just trying to make sense of all the crap I'm reading here!!
I think most of you busted into the beer to early
Most common cause of head gasket failures? AFRs south of 11.85!
Paul
The problem with trying to translate these concepts to automotive use is, I have no idea what the actual A/F ratio is that results in peak cylinder pressure. My WAG is something between your number and slightly below stoichiometric.
Rich
