Scavenge air is delivered by a constant pressure turbocharging system
based on one or more turbochargers, depending on the number of
engine cylinders. For starting and during slow running, scavenge air
delivery is augmented by electrically-driven auxiliary blowers. The
scavenge air receiver incorporates non-return flaps, an air cooler and
the auxiliary blowers; the turbochargers are mounted on the receiver,
which also carries the fixed foot for the exhaust manifold. Immediately
after the cooler, the scavenge air passes through a water separator
comprising a row of vanes that divert the air flow and collect the
water. Ample drainage is provided to completely remove the condensed
water collected at the bottom of the air cooler and separator. Effective
separation of condensed water from the stream of scavenge air is thus
accomplished, a necessity for satisfactory piston-running behaviour.
RTA engines have simple seating arrangements with a modest number