On the related, though not identical, automotive conversion issue; I am

comming around to a hypothesis that the complete ECM and sensor package
of
an unmodified automotive engine may be useable with leaded fuel. I
mention
this because the ECM systems in automobiles and trucks to a commendable
job
of managing mixture under a wide range of conditions.


My reasoning is that the higher average power levels in aircraft use
may
keep the oxigen sensors in the exhaust system hot enough for the
inevitable
lead deposits to sublimate off as fast as they would otherwise build.
My
best guess is that average power levels in automotive use run around
10% of
maximum, due to a lot of time spent idling


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Alot of ECM controlled motors have optional ECMs for "offshore" markets
and those don't use a O2 sensor. The LS1 Gm motor can be bought with
the US puter or the "offshore" one. The offshore one doesn't need
Oxygen info to run properly. I agree the high output of a aircraft
engine will burn off alot of the lead plating that happens on a O2
sensor but it still will lose value and give the ECM a bad reading
after a 100 hours or so. Ya just make it a givin that during every
annual ,oops, conditional inspection you just replace the O2 sensor
with a new one and toss out the old one. They are less then 45 bucks.
That equates to about 1.78 Faa approved certified spakplugs...