A couple of points regarding DCOEs on an 1800cc
engine:
We must remember that rule one in performance
engine building is: Make it breathe. With that
said, almost all of the things we do to improve
the volumetic effeciency of an engine result in
improvements at the upper end of the RPM band,
and in most cases, cannot be realized anywhere
BUT at the extended RPM range. Balanced against
that are valve train inertia and the inherent
limitations of moving materials faster. If we
put all of this into one box, I would say, make
changes to the induction system, valve timing and
lift, cross-flow heads and exhaust tuning only if
you can suffer the drivability loss at the low
end. Engines tweaked to this extent are intended
to operate within about 1200 rpm of the (new) red
line. If this is your application or driving
style (:-) then go for it! If you drive city
and casually, you might reconsider the DCOE
solution.
Rick
'76 Midget
lots of "B"s, Triumphs and Jaguars
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