The document discusses new trends in internal combustion engines to improve fuel economy, safety, emissions and noise/vibration. These trends include cylinder deactivation to reduce pumping losses under light loads, direct fuel injection for lean combustion and lower emissions, variable valve timing and lift to optimize power and efficiency, and turbochargers to force more air into the cylinders and increase power output. While improving performance, these technologies also increase costs and complexity of engine design and maintenance. The internal combustion engine will likely continue powering vehicles with advanced technologies to meet future challenges.

1. New Trends in Internal Combustion
Engines

2. Introduction
• The internal combustion engine has been with
us since about 1885.
• An internal combustion engine (ICE) is a heat
engine where the combustion of a fuel occurs
with an oxidizer (usually air) in a combustion
chamber that is an integral part of the working
fluid flow circuit.
• An IC engine is fed with fossil fuels like
natural gas or petroleum products such as
gasoline, diesel fuel or fuel oil.

3. Will the IC engine be able to cope
with these challenges also in the
future?
1. Fuel Economy
2. Safety
3. Exhaust emission
4. Noise and vibration

4. New Trends in IC Engine
1. Cylinder Deactivation
2. Direct Injection
3. Variable valve timing and lift
4. Turbochargers

5. Cylinder Deactivation
• Cylinder deactivation is one of the technologies that improve fuel economy, the
objective of which is to reduce engine pumping losses under certain vehicle
operating conditions
• Cylinder Deactivation is the method of deactivating Cylinders as per the Power
requirement of the Engine in order to achieve better Fuel efficiency as well as
Emission Control.
• Cylinder deactivation works because only a small fraction of an engine’s peak
horsepower is needed to maintain cruising speed.

6. Working Of Cylinder Deactivation

7. Advantages
• Lean combustion: Lean combustion returns 15 percent increase in fuel
efficiency over a conventional spark ignition engine.
• Cleaner combustion: Cleaner combustion and lower emissions
(especially NOx) than a conventional spark ignition engine.
• Compatibility: Compatible with gasoline as well as E85 (ethanol) fuel.
• Easy fuel burning: Fuel is burned quicker and at lower temperatures,
reducing heat energy loss compared to a conventional spark engine.
• Throttle less induction: Throttle less induction system eliminates
frictional pumping losses incurred in traditional (throttle body) spark
engines.

8. Disadvantages
• Engine balancing- Deactivating cylinders can cause change in engine balancing
which can lead to very violent vibration and increased noise levels.
• Increased cost of manufacturing- the cost of the additional parts like electronic
control module and the complexity in the design and lifter pin mechanism will
increase the cost of manufacturing
• Overall increase in weight- Due to the presence of additional components like
hydraulic lines used in hydraulic sub system, lifter locking mechanism, and solenoid
valves etc.
• Complexity of system makes maintenance difficult. - Complex lifter locking
mechanism and solenoid valves are difficult to maintain.

9. Direct fuel Injection
Direct injection is where fuel is
injected (directly) into the
cylinders, not mixed with air in
the inlet manifold or inlet ports
before being drawn into the
cylinders.

10. Types Of Direct Injection Systems
MPFi Engine
Multi Point Fuel Injection system.
In this system each cylinder has
number of injectors to supply/spray
fuel into the cylinders .
CRDi Engine
Common Rail Direct injection
system. In this system, all the
injectors are supplied by a common
fuel supply line or a manifold
called the common rail.

11. Advantages of Direct Fuel Injection
Due to multiple injections, uniform A/F
mixture supplied to cylinder; thus
difference in power developed in each
cylinder is minimum. Noise and
Vibration from the engine is less.
Since the engine is controlled by ECU,
accurate A/F mixture supplied resulting
in complete combustion leading to
effective utilization of fuel supplied and
hence low emission level.

12. Disadvantages of direct fuel injection
• The primary disadvantages of direct injection engines are complexity and
cost.
• Direct injection systems are more expensive to build because their
components must be more rugged -- they handle fuel at significantly
higher pressures than indirect injection systems and the injectors
themselves must be able to withstand the heat and pressure of
combustion inside the cylinder.

13. Variable Valve Timing And Lift
• Principle is to use a two-
position advance or retard of
either an engine’s intake or
exhaust camshaft to better
match the engine’s operating
conditions . Two main
factors that determine an I.C
engine performance are
• The point at which valves
open.
• The duration of the valves
being open.

14. Types of Variable Valve Timing System
VTEC Engine (Variable
Valve-Timing and Lift
Electronic Control) VTEC
works by varying valve
timing and lift to compensate
for the time delay and out-of-
phase arrival of the air-fuel
charge at the intake valve.
Shifts valve between two
separate sets of cam lobes—
one for high-speed operation
and one for low.

15. Advantages
• Low fuel consumption appreciable
increase in power
• Lower tail pipe emission.
• Valvetronic system, optimize engine
power and efficiency.
• Reduces pumping losses

16. Disadvantage
• Has a complex design to manufacture
• Is expensive
• High wear and tear occurs
• Very difficult to maintain

17. Turbocharger
• A turbocharger is a turbine-driven forced induction
device that increases an internal combustion engine's
efficiency and power output by forcing extra air into the
combustion chamber.
• This improvement over a naturally aspirated engine's
output results because the turbine can force more air, and
proportionately more fuel, into the combustion chamber
than atmospheric pressure alone.
• Turbochargers are commonly used on truck, car, train,
aircraft, and construction equipment engines. They are
most often used with Otto cycle and Diesel cycle internal
combustion engines.

18. Working principle of a turbocharger
• A turbocharger is a small radial fan pump
driven by the energy of the exhaust gases
of an engine.
• A turbocharger consists of a turbine and a
compressor on a shared shaft.
• The turbine converts exhaust to rotational
force, which is in turn used to drive the
compressor.
• The compressor draws in ambient air and
pumps it in to the intake manifold at
increased pressure, resulting in a greater
mass of air entering the cylinders on each
in take stroke.

19. Working of turbocharger

20. Advantages
• The more increase the pressure of the intake air above the local
atmospheric pressure (boost), the more power the engine produces.
• Engines burn air and fuel at an ideal ratio of about 14.7:1, which
means that if you bum more air, you must also bum more fuel.
• This is particularly useful at high altitudes: thinner air has less
oxygen, reducing power by around 3% per 1,000 feet above sea
level, but a turbocharger can compensate for that loss, pressurizing
the intake charge to something close to sea level pressure.

21. Disadvantages
• Cost and complexity
• Detonation
• Large space requirement
• Turbo lag

22. Conclusion
• Internal combustion engines are among the most important engineering
applications. The theory of application either depends on Diesel or Otto
cycles. They are categorized either according to the operating cycle, or
due to the mechanism of working.
• Each type of engines has some advantages over the other one. Thus, the
selection of the appropriate engine requires determining the conditions of
application.
• Despite the green hype, internal-combustion engines with its latest and
advanced technology will keep powering vehicles for the foreseeable
future