1.8L head on 2.0L block

[amalventano at sc.rr.com (Allyn)]

> More airflow=better efficiency=more power.

umm
depends on runner diameter/taper / rpm
rpm change = different intake air pulse size/speed, therefore some
configurations make more power at low rpm, where some others make more power
at higher rpm.
just boring the crap out of intake doesnt give you more airflow in all
situations. narrower intake passages cause faster air velocity while filling
the cylinder, and that very momentum can actually cause a forced induction
effect, as it squeezes that much more air in the cylinder just before the
intake valve closes. this is how some engines can have a volumetric
efficiency approaching (and possibly exceeding) a value of 1. the narrower
intake is not perfect though, as it begins to restrict airflow at higher
rpm.

so... from an intake perspective, a stock 1.8 head is meant to flow most
efficiently at a higher rpm than a stock 2.0 head is meant to.
Al