The
Radium
Coolant
Expansion
Swirl
Tank
features
three
ports
that
use
-6AN
to
9/16-18
O-ring
adapters
(not
tapered
pipe
threads)
for
a
positive
seal.
The
main
tank
is
a
2-piece
design
constructed
of
cast
aluminum.
The
two
halves
(shown
below)
are
welded
together
along
with
a
CNC
billet
aluminum
cap
receiver
which
mates
to
any
standard
32mm
"import"
style
pressure
cap.
Coolant
expansion
tanks
are
necessary
for
proper
air
bleeding
in
applications
that
utilize
a
low
mounted
radiator.
The
Radium
Engineering
tank
also
has
an
internal
swirl
feature.
Hot
pressurized
coolant
from
the
cylinder
head
is
sent
into
the
vortex
chamber's
inlet
tangentially
and
accelerated
to
a
high
rate
of
rotation.
This
is
an
old
hot
rod
trick
to
help
aid
in
deaerating
the
system.