The Cosworth process is a precision sand casting
process, which was developed in 1978 for non-ferrous casting, initially
aluminium alloys, to engineer the Cosworth engine. The mould and
core-making stages are similar to conventional sand casting, although
zircon sand is used instead of silicon, due to its greater expansion
predictability. The main feature of this process is that the metal is
pumped into the mould through the base using pressure assisted feeding
through a simplified gating system.
The absence of conventional gating and feeding systems results in
castings free of porosity (due to hydrogen) and inclusions (due to
alumina). These are common in sand and gravity die casting and impair
the metallurgical integrity and mechanical properties of the casting.
The process also eliminates a number of minor problems associated with
conventional techniques including: blowholes from chills, cores and
adhesives; inaccurately located cores and mould halves; and
metallurgical inadequacies (particularly poor hardness or strength). It
also reduces fettling time. The process was more recently extended to a
number of commercial castings with the opening of a new foundry in 1984.
In 1993 the Ford Motor company selected the Cosworth process for its
Windsor, Ontario, Plant. The American Foundrymen's Society has
identified the Cosworth process as being a key emerging process, needing
further investigation to develop commercial opportunities.

Can
cast thinner sections, allowing the design of lighter, more robust
components and resulting in considerable weight saving.

Produces
exceptionally high strength and ductility due to improved metallurgical
consistency during solidification.

Gives
high dimensional accuracy, resulting in minimum fettling and machining.

Castings
are pressure-tight due to the absence of porosity and inclusions.

Tooling
is comparatively inexpensive.

Is
suitable for medium- to high-volume production.

Gives
high metal yields and high sand reclamation.