I was reading about that in Diesel Power a few months back. It is one of the
(many) space saving designs they used.

Still not quite sure why they made it a 4.5L V8 instead of a 4.5L I4, V6 or
I6. That would have saved more money and design issues.

Someday, maybe I'll pop one of those in my Avalanche if the 5.3L gasser
gives up the ghost.

Seems like semantics to me.  Call something by another name!  Even the
picture shows what sure appear to be manifolds.  From the writeup,
indeed it sounds like the exhaust manifold design is simpler, and
depending on how you partition parts and functions, the exhaust
manifold may be part of another part or assembly.  But to say the
engine has no manifolds seems like a lot of hyperbole to me.

It has both intake and exhaust manifolds- the intake manifold is part
of the valve cover, the exhaust manifold sits in the valley and
connects directly to the turbo.

Dave

I've been wondering how long it would take before a manufacturer built
an automotive diesel v8 this way. Its been the norm in locomotive
engines for decades- both the EMD 2-strokes and the GE FDL 4-stroke
locomotive diesels have the exhaust in the "valley". On the GE, the
intakes are "logs" along the outside where car v-type engines would have
exhaust manifolds, and on the EMD 2-strokes the intake is through the
cylinder case. Caterpillar marine diesels are laid out the same way-
exhaust and turbos in the "V", intake trunks along the outside of the "V".