The Garage 285

focus Gaskets 34
Don’t blow
a gasket
The Garage’s Richard
Barnett looks at the
technology behind
gaskets and the
companies that are
leading the way with
their evolution
Gaskets
Take a closer look
at the make up of a
modern car and it’s
interesting to see
just how many components
are similar to those
found in cars considerably
earlier.
Radiators for example still
house the coolant that circulates
around the engine,
the principle being the same
as found on cars from the
1980s, although how the
circulation is achieved has
changed considerably.
It’s the same with gaskets,
the all-too-often unsung heroes
of allowing surfaces to
mate together effectively in
many tough situations.
The UK’s leading aftermarket
supplier is FAI Automotive,
whose 30-years’ presence
has seen the market
change and, unsurprisingly,
the technology.
“The market has seen
many changes not only in
gasket design but also material.
The most significant is
the move away from composite
fibre head gaskets to MLS
(multi layered steel.) The
reason for this move is the
ever-increasing demands for
modern engines to be more
efficient and cleaner and by
introducing the multi-layered
steel (MLS) head gasket
OE manufacturers have been
able to increase the pressures
within the combustion
chamber. This enables the
engine to run hotter, burning
fuel more efficiently and
reduce CO² and other toxic
emissions,” FAI says.
Today, making gaskets
is no easy process, but the
production process requires
stages that aren’t cheap to
carry out, as FAI’s spokesman
explains: “A vital and
costly process during manufacture
is heat treatment,
this is essential to stabilise
the steel after it has been
cut and formed, so the
work hardened areas are returned
to the original tensile
strength. Evidence of this
process (golden surface) cannot
always be seen, as many
MLS gaskets are coated with
a black polymer to promote
micro sealing.
“Some of the latest generation
steel head gaskets are
now single layered of approx.
0.25mm thickness, but to
ensure no cylinder pressure
loss they have an additional
fire rings (between 0.02mm
& 0.04mm thickness) that
are welded to each cylinder
bore using a pulse laser.
Due to the high development
costs of the pulse lasers this
technology is only available
in a small number of wellestablished
highly advanced
gasket factories worldwide.”
Evidence of the UK car
parc’s complexity the FAI
gasket range has 6000 part
numbers covering more than
65,000 vehicles.
Ajusa’s gasket range features
products made from
FiberMax, MLS and Metal-
Elastomer to take into account
the various technologies
selected by VMs today.
As always, the cylinder head
gasket is the most important
one in a car but as engines
become more efficient, the
work of the head gasket becomes
harder.
Modern engines are more
powerful for their size than
they used to be and are often
made from aluminum
and light alloys but because
those materials are softer
they expansion and contrac-
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