Seminar on VTEC Engine

1. Gandhi Institute of Engineering and
Technology,
Gunupur
Presentation on VTEC Engine
By: Rahul Bhoi
11ME034
Mechanical Engineering

2. INTRODUCTION
 VTEC (Variable Valve Timing and Lift Electronic Control)
is a valve train system developed by Honda
 improve the volumetric efficiency of a four stroke internal
combustion engine .
 The VTEC system uses two camshaft profiles and
electronically selects between the profiles.
 It was invented by Honda engineer Ikuo Kajitani.
 This was the first system of its kind.

3. HISTORY
 Originated from REV (Revolution-modulated valve
control) introduced on the CRB400 in 1983 known as
HYPER VTEC.
 The earliest VTEC-E implementation is a variation of
SOHC VTEC.
 Its introduction in usage was to enhance the output
power .

4. BASIC MECHANISMS
 The basic mechanism used by the vtec technology is
hydraulically actuated pin.
 Pin reached to rocker arms.
 A spring mechanism used to return
the pin back.
 Comprises of two camshaft
lobes.

5. PRINCIPALS
 One of the cam lobes on the left hand have a wider
profile , opens its valve earlier.
 For more time and close it later in compare to the other.
 The fuel is allowed to enter through one valve
completely , while other valve opens partly.

6. SERIES OF VTEC ENGINES
 SOHC VTEC
 VTEC –E
 3 STAGE VTEC
 I- VTEC

7. VTEC-E
 Vtec E implementation is for the economy.
 Uses swirling to promote more
efficient air fuel mixing in engine chamber.
 Only one intake cam lobe used.
 Making engine to operate in 16
valve working mode.

8. I-VTEC
 The intake camshaft is now capable of advancing between
25 and 50 degrees.
 Phasing is implemented by a computer-controlled, oil-driven
adjustable cam gear.
 I-VTEC V6 that includes Honda's cylinder deactivation
technology.

9. VTEC IN MOTORCYCLES
 Firstly used in 2003 in sports bikes.
 One intake valve remains closed until a threshold of 7000
rpm is reached.
 Second valve is opened by an oil-pressure actuated pin.
 Uses a single camshaft to provide two timing routines for
the intake .

10. ADVANTAGES
 Better fuel efficiency.
 High initial torque with relevant high power.
 Lower emission.
 Strong performance.

11. LIMITATIONS
 Higher cost of engine.
 More complex mechanism.
 Wear and Tear problems.
 Failed to overcome turbo charging.
 Decreased engine life.

12. FUTURE OF VTEC
 Implementation on performance engines.
 Better opportunities of higher petroleum prices.
 Consideration on its disadvantages gives improvement in
it.
 Economy and satisfaction to be estimated.