ox sensor on sequential efi,high overlap cam....

[Tom Sharpe]

Group thoughts,

Wide centers help Idle. Why??? Exhaust closes sooner??? Intake opens later???
Narrow overlaps have more torque and higher efficiency (BM??) at peak. Seem to
be peakier and "get UP on the Cam" more/sooner.

Overlap causes EGR as well as intake charge in exhaust system. (intake and
exhaust dilution).

EFI is probably worse as most squirt fuel on the intake valve before it opens.
Called "settle time" by Edelbrock. (more time to evaporate). That means the
richest mixture is sucked in (thru) first.

Exhaust tuning (pulses) suck the cylinder dry at some RPMs and block the exit at
others. Turbo motors don't care. Cam duration and centers (overlap) can really
hose up a system or make it purr like a kitten.

Assuming we can measure the AFR with our O2 sensor (or EGOR) and tune to 14.7 or
12.5 or xxx, it still will not tell us how the motor is running. We still need
to adjust each combination,,,, say to highest vacuum or whatever,,, so the it
runs good (and does not polute). We still need to tune.

Maybe we just set the idle speed above the problem areas for those of us with
too much cam...( like too short shorts ) a lot is good, more is better and too
much is just right.

starting to ramble    sorry  Tom