The Jabiru directions recommend the lip on the lower opening plus the
outlet opening be three times the size of the inlet. Jim McCormick at Jabiru
Pacific feels that there should be two paths for the air to flow under the
engine. One small slit to allow air to flow over the sump fins and another to
go through the oil cooler, keeping in mind that the air under should be
kept as minimal as needed to allow a favorable balance of air over the
cylinders. Don't forget the ram air tubes called for to cool the magnetos and
the
RDACK if you have one.
Jim Wright
Spring Hill, FL
