HONDA Insight - Manual (Page 75)

75
I
NTEGRATED
H
EAD
The Honda Insight's cylinder head has a unique,
cast-in exhaust manifold that saves weight and
increases exhaust heat retention.
The exhaust ports are located inside the cylinder
head and are surrounded by a water jacket. As coolant
passes through the jacket, its temperature is increased
by the exhaust heat.
The individual exhaust-manifold runners are part
of the head casting, just like the exhaust ports. The
shape and length of the manifold runners is optimized
for efficient flow, and the system offers the
advantages of faster heat transfer to the catalyst, for
faster lightoff. This decreases exhaust emissions and
increases fuel efficiency. Eliminating the need for a
separate exhaust manifold also increases manufacturing efficiency, and offers greater compactness and
lower engine weight. The IMA engine is the world's first production gasoline engine to use an integrated
exhaust manifold.
New spark plug positions and other innovations yield compact combustion chambers.