[Spridgets] Intake Manifolds

[corvallis at peoplepc.com]

"In a running engine, camshaft overlap causes hot exhaust gases to expand
and rise into the intake manifold as the intake valve is opening and the
exhaust valve is closing.  The incoming fuel/air mixture is then
contaminated.  More importantly, the carburetor throats are effectively
'choked' by the reverse flow of hot exhaust gases, causing a restriction of
the intake charge.  This occurrence is commonly called "reversion".  The use
of Product Engineering's Anti-Reversion Shear Plate combats this problem by
capturing and redirecting the errant exhaust gases, turning them back into
the engine.  This method uses the gases own velocity to boost the speed of
the incoming fuel/air mixture and break up the molecules for better
atomization.  The redirected gases also shear and atomize the raw fuel that
typically drips from the base of the carburetor's bores."
>From http://www.racingcomponents-llc.net/shear_plates.htm