43
october 2014
international
construction
ENGINES
Emissions impact
L
egislation on exhaust emissions has been focusing the
minds of diesel enginemanufacturers for years, and 2014
will be remembered for regulation landmarks, with Stage
IV coming into force in Europe and the equivalent USTier 4
Final and Japanese Stage 4.
Although this is the endof the road for now, a further Stage
V is in the works for implementation around 2019.This is
likely to regulate engines with power outputs not covered by
the current standards, as well as tightening the requirements
on particulatematter (PM) emissions.
PM has been the focus of the last two rounds of emissions
reduction alongwithnitrous oxide (NOx).The current levels
being achievedput the concentrations of pollutants emerging
from exhaust pipes around the same level as the ambient air in
many cities. In fact,many enginemanufacturers will say – only
half jokingly – that their engines now act as air cleaners in some
places.
However, legislators feel there is still more to do. Research
shows that it is the extremely fine particles – those many times
smaller than the thickness of ahumanhair – that cause themost
health issues, and it is these that will be regulated. Current laws
place limits on the weight of particles that can be emitted, but
in future this is likely to shift to a mechanism that will control
the number of fine particles, possibly by some sort of count per
unit ofmass.
But that is aconcern for the future. In termsof thenewengines
coming onto the market and being installed in construction
machines, the focus right now remains onTier 4Final/Stage IV.
Engine development
Bobcat is introducing its own-brand Stage IV engines. The
constructionequipmentmanufacturer announced in June that it
had begun the transition tomeet the new emissions regulations
formachines greater than 37 kW.
According to Bobcat, this has resulted in significant changes
to engine design, added components and special service
requirements, with the incorporation of non-DPF (diesel
particulate filter) Stage IIIB/Stage-compliant Bobcat branded
engines in selectedBobcatmachines.
It said non-DPF technology had been chosen as a customer-
preferred solution that minimises long-term Stage IIIB/Stage
IV parts and maintenance expenses. Engines with a non-DPF
systemhave a simpler design, need lessmounting space, haveno
risk of thermal damage and do not require ash cleaning, it said,
adding that non-DPF engines also had fewer service needs and
offered better fuel economy.
Bobcat is part of the Doosan group, and the new non-DPF
engines are being built in conjunction with Doosan Infracore
Engine Business Group.They will be added to selected Bobcat
machines in 2015.
There will be three engine models – the D18, D24 andD34,
ranging from1.8 to3.4 litredisplacement, formachines ranging
from 37 kW to 74 kW. The engines will be used in 500, 600,
700 and 800 platformBobcat loaders.
The new Doosan engines have undergone 140,000 hours of
testing to ensure their reliability. According to Doosan, these
new compact diesel engines will offer high power output with a
high low-end torque. All three models are powered to improve
fuel efficiencywhile reducing noise, emissions and vibration.
The Doosan Infracore Engine Business Group said it had
produced over 1.5 million engines since 1976, and these are
usedworldwide in compact and heavy construction equipment,
commercial andmilitary vehicles, generators and ships.
Bobcat also engaged the engine expertise of global engineering
leaders, Ricardo, FEV and SWRI, who together brought
>
Emissions impact
With the Stage IV/Tier 4 Final emissions laws coming
into force, enginemanufacturers have been hard
at work tomeet tough pollution limits.
SarahMcCay
takes a closer look at some
of the new, lean, clean and efficient engines
hitting themarket
Bobcat is
introducing its
own Stage IV
engines and
has begun the
transition to
meet the new
emissions
regulations for
machines greater
than 37 kW.
