Cast Iron Manifold
Cast iron manifold is also called as
exhaust manifold or inlet manifold, normally produced by
gray iron ASTM A48 CL 30, 35, DIN
GG20, GG25, or known as grey iron class 200 and 250.
Dandong Foundry in China produced manifold castings for our client
overseas by shell molding process.
We used hot resin sand molds to make the shell and core of the
castings. This casting process could meet the requirements to the
surface quality, casting
defects, and thin wall thickness.
The clean inside tubes and less casting defects are the key points
of the quality, which is impossible to meet by the traditional
green sand casting
processes. The following photo is showing these resin sand
shell and cores.
Gray cast iron GG20, or class 200 is the
most suitable casting material for the manifold. It is mainly
because gray iron has cheaper production costs, good cast
properties, good resistance to deformation and heating. Some clients
may choose GG25, e.g. class 250 grades because of higher tensile
strength, however, manifolds normally have very thin wall thickness
such as 5 to 6mm, which will cause the hardness of the castings
higher, which will cause difficulty for drilling. Moreover, higher
grade will cause the casting bodies more crispy.
The prices of manifold castings are not
low because its difficulty to production, and high prices of yellow
phenolic resin sand. Normally, one set of manifolds needs several
sets of metal patterns, and their sand molds need assembly, which
will cause much more production process and time. There are not many
iron foundries in China who
could produce the manifolds very well.