The engine's fuel manifold (visible at the right-hand side of dsc87940.jpg has also been cut away.
A line led from
the fuel inlet to the fuel manifold. The fuel then travelled between the two walls of the thrust chamber to
the injector at the forward end of the engine, providing regenerative cooling
and preventing the inner wall from melting.
A coil was welded between the two walls,
forcing the fuel to circulate through the resulting spiral passage. This
increased the velocity of the fuel, resulting in higher heat absorption.