The document discusses various technological advancements in internal combustion (IC) engines, including i-VTEC, CRDI, and ATFT. i-VTEC is a Honda system that improves volumetric efficiency by regulating intake and exhaust valve opening based on engine speed, achieving both high power and low fuel consumption. CRDI or Common Rail Direct Injection is used in modern diesel and some petrol engines. It uses a common high-pressure fuel rail to directly inject fuel into cylinders, allowing more efficient fuel-air mixing and electronic control of injection timing and pressure. ATFT or Advanced Tumble Flow Technology induces a swirling air-fuel motion in the combustion chamber to aid mixing and improve combustion/efficiency

1. Technological Advancements in
IC Engine

2. i-VTEC Engine
● i-VTEC (Intelligent Variable Valve Timing & Lift Electronic Control) is a system
developed by Honda which was said to improve the volumetric efficiency of a
four-stroke internal combustion engine.
● Resulting in higher performance at high RPM, and lower fuel consumption at
low RPM. The VTEC system uses three camshaft profiles and hydraulically
selects between profiles.
● It was invented by Honda engineer Ikuo Kajitani.

3. i-VTEC: high power and low fuel consumption
● control openings of two intake valves
○ i-VTEC regulates the opening of air-fuel intake valves and exhaust valves
in accordance with engine speeds.
○ opening a small amount at low engine speeds and fully opening at high
engines speeds, achieving both high power and low fuel consumption
● Idling one intake valve
○ The new i-VTEC engine is agile and intelligent: at low engine speeds one
of the two intake valves is idled. The engine sips gasoline, using a lean
fuel mix at low engine speeds for further improved combustion efficiency.

5. CRDI Engine
● Most modern engine's fuel systems use an advanced technology known as CRDi or
Common Rail Direct Injection.
● Both petrol and diesel engines use a common 'fuel-rail' which supplies the fuel to
injectors. However, in diesel engines, manufacturers refer to this technology as CRDi
whereas Petrol engines term it as Gasoline Direct Injection (GDI) .
● Direct injection of the fuel into the cylinders of a engine via a single common line called
the common rail which is connected to all the fuel injectors.
● Instead of providing separate pumps for fuel supply. The common rail alone supplies high
pressure fuel to each cylinder.
● This allows fuel to combine with air much more efficiently.

6. ● CRDI ensures the fuel injection timing, quantity of fuel and atomisation of fuel
spray are controlled electronically using a programmable control module.
● This allows multiple injections at any pressure at any time (within predefined
limits), providing a level of flexibility which can be exploited for better power,
fuel consumption and emission control.
● The electronic control and multiple injection reduced the noise to great extent.
● Ultra high pressure crdi (1800 bar) generating the ideal swirl and allowing the
air-fuel mixture to form uniform combustion and greatly reduced NOx emissions
CRDI Engine

9. ● It is basically a design optimization in the engine, which induces a
swirling or spinning motion in the air-fuel mixture as it enters the
combustion chamber.
● The swirling motion aids in better mixing of the fuel particles with air.
● The advantage of this technology is a more efficient combustion of
fuel, resulting in better fuel economy and cleaner emissions.
ATFT- (Advanced Tumble Flow Technology)

10. Features of ATFT:
● Tumble flow also indicates that the air-flow circulating in the direction of the
cylinder axis. Thus, it is beneficial in homogenizing the air-fuel mixture.
● It also has little effect on accelerating the combustion process by generating
turbulence. So, the tumble flow effectively improves the engine combustion at
light load when it completes near the end of the compression stroke.
● Hero Motocorp offers the ATFT technology on its CBZ Xtreme, Hunk and
Achiever models.

12. Join Skillshare
IC Engines online course
Thank you!!