Seminar Report on I VTEC HONDA (Prof. Mr. V. M. Bukka Sir)

The most important challenge facing car manufacturers today is to offer vehicles that deliver excellent fuel efficiency and superb performance while maintaining cleaner emissions and driving comfort. This paper deals with iVTEC (intelligentVariable valve Timing and lift Electronic Control) engine technology which is one of the advanced technology in the IC engine. iVTEC is the new trend in Honda’s latest large capacity four cylinder petrol engine family. The name is derived from ‘intelligent’ combustion control technologies that match outstanding fuel economy, cleaner emissions and reduced weight with high output and greatly improved torque characteristics in all speed range. The design cleverly combines the highly renowned VTEC system which varies the timing and amount of lift of the valves with Variable Timing Control. VTC is able to advance and retard inlet valve opening by altering the phasing of the inlet camshaft to best match the engine load at any given moment. The two systems work in concern under the close control of the engine management system delivering improved cylinder charging and combustion efficiency, reduced intake resistance, and improved exhaust gas recirculation among the benefits. iVTEC technology offers tremendous flexibility since it is able to fully maximize engine potential over its complete range of operation. In short Hondas iVTEC technology gives us the best in vehicle performance. SR.NO TOPIC NAME PAGE NO. 1. INTODUCTION 08 2. OBJECTIVE 09 33. TERMS RELATED TO iVTEC 3.1 Volumetric Efficiency 3.2 Torque 3.3 Power 3.4 Camshaft 3.6 Engine Breathing 3.7 Electronic Control Unit (ECU) 11 44. VTEC 4.1 Basic VTEC Mechanism 4.2 DOHC VTEC 4.3 SOHC VTEC 4.4 3Stage VTEC 13 5. VALVE TIMING CONTROL (VTC) 19 6. iVTEC SYSTEM 20 7. ADVANTAGES OF iVTEC SYSTEM 23 8. DISADVANTAGES OF iVTEC 23 9. APPLICATIONS OF iVTEC SYSTEM 24 110. CASE STUDY OF ‘HINDA CITY’ 10.1 Specifications OF iVTEC Engine. 10.2 Performance 25 111. FUTURE TRENDS 11.1 Pneumatic Valve 11.2 VTEC in Turbo 11.3 iVTEC in Motorcycle 27 112. TOP 10 iVTEC ENGINES 12.1 B16A 12.2 B16B Type R 12.3 B18C1 12.4 B18C Type R 12.5 C32B Type R 12.6 F20C1 12.6 H22A1 12.7J37A4 12.8 K20A Type R 12.9 K24A2 28 13. CONCLUSION 30 14. REFERANCE 31

“intelligent-VALVE TIMING AND LIFT ELECTRONIC

CONTROL”

Seminar Report

Submitted in the partial fulfillment of the requirements for the diploma of

DIPLOMA IN MECHANICAL ENGINEERING

In the faculty of Engineering and Technology Government Polytechnic, Aurangabad-431005

Guided By,

Prof Mr V M Bukka Sir

(Lecturer in Mech Engg.)

Submitted by,

Mr Mahesh Kachru Kawade

(122041)

Department Of mechanical Engineering

Govt Polytechnic, Aurangabad-431005.

Academic Year 2014-15

GOVERNMENT POLYTECHNIC AURANGABAD

C E R T I F I C A T E

This is to certify that the thesis titled “intelligent- VALVE TIMMING AND LIFTELECTRONIC CONTROL “represents the bonafide work carried out by Mr KAWADE MAHESH KACHRU submitted in partial fulfillment of the requirement for the diploma in

“Mechanical Engg “The work has been carried out in the Department of Mechanical Engg Of Government Polytechnic, Aurangabad (An Autonomous Institute Of Govt Of Maharashtra) under the guidance of Prof Mr.V.M.Bukka.

Prof V M Bukka Sir Dr A V Peshwe Sir

(Seminar Guide.) (HOD of Mech Dept.)

Dr P.R Pattalwar Sir

(Principle)

ACKNOWLEDGEMENT

Firstly I thank none but one almighty GOD For showering his mercy and blessing on me and

being with me always, and he is with me hence only I can finished my work successfully Then I thank

my parents for their blessing, encouragement and moral support.

I would like to take this opportunity to express our deep sense of gratitude and respect to

our guide Prof V.M Bukka Sir, Lecturer in Mechanical Engineering It was a great privilege to

get his constant inspiration and guidance during our seminar work

I extend word of thanks to Prof Dr A V Peshave Sir, head of the department of

Mechanical Engineering and all those teaching and non-teaching staff stood behind to help andsupport us

I am also thankful to our beloved principle Dr P R Pattalwar Sir for providing all

necessary activities and encouraging us throughout the work

I am highly obliged to entire friends group providing the way in the difficult time

Thankful I ever remain……….

Date:

Place: Aurangabad Mr KAWADE MAHESH KACHRU

(122041)

i-VTEC ENGINE

ABSTRACT

The most important challenge facing car manufacturers today is to offer vehicles thatdeliver excellent fuel efficiency and superb performance while maintaining cleaner emissions

and driving comfort This paper deals with i-VTEC (intelligent-Variable valve Timing and lift

Electronic Control) engine technology which is one of the advanced technology in the IC

engine i-VTEC is the new trend in Honda’s latest large capacity four cylinder petrol enginefamily The name is derived from ‘intelligent’ combustion control technologies that matchoutstanding fuel economy, cleaner emissions and reduced weight with high output and greatlyimproved torque characteristics in all speed range The design cleverly combines the highlyrenowned VTEC system - which varies the timing and amount of lift of the valves - withVariable Timing Control VTC is able to advance and retard inlet valve opening by altering thephasing of the inlet camshaft to best match the engine load at any given moment The twosystems work in concern under the close control of the engine management system deliveringimproved cylinder charging and combustion efficiency, reduced intake resistance, and improvedexhaust gas recirculation among the benefits i-VTEC technology offers tremendous flexibilitysince it is able to fully maximize engine potential over its complete range of operation In shortHonda's i-VTEC technology gives us the best in vehicle performance

3.3 Power 3.4 Camshaft 3.6 Engine Breathing 3.7 Electronic Control Unit (ECU)

CASE STUDY OF ‘HINDA CITY’

10.1 Specifications OF i-VTEC Engine

12.6 H22A1

28

12.7J37A4 12.8 K20A Type R 12.9 K24A2

1 INTRODUCTION

1.1 Definition

An internal combustion is defined ‘as an engine in which the chemical energy of

the fuel is released inside the engine and used directly for mechanical work’ The internal

combustion engine was first conceived and developed in the late 1800’s The man who isconsidered the inventor of the modern IC engine and the founder of the industry is Nikolaus Otto(1832-1891)

1.2 Discovery

Over a century has elapsed since the discovery of IC engines Excluding a fewdevelopment of rotary combustion engine the IC engines has still retained its basic anatomy Asour knowledge of engine processes has increased, these engines have continued to develop on ascientific basis The present day engines have advances to satisfy the strict environmentalconstraints and fuel economy standards in addition to meeting in competitiveness of the worldmarket With the availability of sophisticated computer and electronic, instrumentation haveadded new refinement to the engine design

From the past few decades, automobile industry has implemented many advancetechnologies to improve the efficiency and fuel economy of the vehicle and i-VTEC engineintroduced by Honda in its 2002 Acura RSX Type S is one of such recent trend in automobileindustry

The VTEC system provides the engine with multiple cam lobe profiles optimized forboth low and high RPM operations In basic form, the single barring shaft-lock of a conventionalengine is replaced with two profiles: one optimized for low-RPM stability and fuel efficiency,and the other designed to maximize high-RPM power output The switching operation betweenthe two cam lobes is controlled by the ECU which takes account of engine oil pressure, enginetemperature, vehicle speed, engine speed and throttle position Using these inputs, the ECU isprogrammed to switch from the low lift to the high lift cam lobes when the conditions mean thatengine output will be improved At the switch point a solenoid is actuated which allows oilpressure from a spool valve to operate a locking pin which binds the high RPM cam follower tothe low RPM ones From this point on, the valves open and close according to the high-liftprofile, which opens the valve further and for a longer time

2 OBJECTIVE

The objective of seminar report is;

1) To know the VTC system

2) To know the components

3) To understand the construction & working

4) Operations

i-VTEC SYSTEM:

he latest and most sophisticated VTEC development is i-VTEC ("intelligent" VTEC), whichcombines features of all the various previous VTEC systems for even greater power bandwidth and cleaner emissions With the latest i-VTEC setup, at low rpm the timing of the intakevalves is now staggered and their lift is asymmetric, which creates a swirl effect within thecombustion chambers At high rpm, the VTEC transitions as previously into a high-lift, long-duration cam profile

T

The i-VTEC system utilizes Honda's proprietary VTEC system and adds VTC(Variable Timing Control), which allows for dynamic/continuous intake valve timing andoverlap control

The demanding aspects of fuel economy, ample torque, and clean emissions can all

be controlled and provided at a higher level with VTEC (intake valve timing and lift control) andVTC (valve overlap control) combined

The i stands for intelligent: i-VTEC is intelligent-VTEC Honda introduced many

new innovations in i-VTEC, but the most significant one is the addition of a variable valveopening overlap mechanism to the VTEC system Named VTC for Variable Timing Control, thecurrent (initial) implementation is on the intake camshaft and allows the valve opening overlapbetween the intake and exhaust valves to be continuously varied during engine operation

ACTUAL DIAGRAM OF VALVE IN i-VTEC

3 TERMS RELATED TO i-VTEC:

3.1 Volumetric Efficiency

The engine produces a certain force from every power stroke as a result of burningair/fuel expanding This force generally gets less for every power stroke as the engine revolvesfaster, as the air/fuel mixture has less time to get sucked into the cylinder The volumetricefficiency of a engine at a certain speed is the pressure of air/fuel mixture inside the cylinderwhen the piston has finished sucking in the mixture, as a percentage of the atmospheric pressure.Thus an engine with 80% volumetric efficiency at a certain speed will have a mixture pressure of80% of atmospheric pressure when the piston is at bottom dead centre after the intake stroke

3.2 Torque

The torque of an engine is the total force the engine produces at a certain speed This

is a rotating force, but the easiest way to think of torque is to imagine an engine with a drumattached to it, winching up a weight vertically The torque of the engine is the force that raisesthe weight The torque of an engine will increase as the engine rotates faster, because the number

of power strokes per time period increases However, the volumetric efficiency of an engine willdrop after a certain speed, so each power stroke has less force The point where the increase inforce (from the increased number of power strokes) is equal to the drop in force (because of lessefficiency) is the point of peak torque This occurs anywhere from 2000 - 7000 rpm, depending

on the engine A higher performance engine will generally have a higher efficiency and maintainthis longer, so will have peak torque at higher revs In the case of my B16A VTEC engine, thetorque peak is at about 7000 rpm, which is one of the highest of any mass produced vehicleengine

be lifted The peak power point for an engine is the point where, ideally geared, the most forcewill be available at the wheels The peak power point will always be above the peak torquepoint In my B16A engine, the peak power occurs at about 7800 rpm

3.4 The Camshaft

The camshaft has a very big influence on engine breathing The camshaft controlshow long the intake and exhaust valves are open, and how high they open The intake valvesalways open before the piston is at the top of the cylinder (and started sucking) and close afterthe piston is at the bottom of the cylinder (and stopped sucking) The shape of the cam lobeslimits the valve opening and closing to a gradual opening from closed to fully open, then agradual closing to fully shut (Otherwise the value train will destroy itself at high speeds) Sowhile the value opens before the cylinder is sucking, it is not open that much There is a trade off

in terms of efficiency with the camshaft It is possible to open the values earlier, and have thevalve open further for a longer period while the engine is sucking in mixture (it works the samefor the exhaust) The valve will be open before the piston has reached the top of the cylinder, andsome of the mixture will be pushed out of the cylinder but the piston Because of the momentumeffect of the intake mixture, this loss is less at higher revs, and more at lower speeds, when theintake mixture has not much momentum to overcome mixture being forced out of the cylinder

A camshaft that opens the values early and closes them late (called long duration, or ‘wild’ or

‘lumpy’) will be more efficient at higher engine speeds and less efficient at lower engine speeds

A camshaft that opens later and closes earlier (called short duration, or ‘mild’) will be moreefficient at lower engine speeds and less efficient at higher engine speeds

3.5 ECU

The ECU (electronic control unit = the fuel injection computer) is the heart of theengine Basically the purpose of the ECU is to control fuel injection and ignition for the engine,for all the conditions which the engine can be expected to run under This is a fairly complicatedjob considering the number of external factors that can influence the amount of fuel that needs to

be injected into the engine, and the rate at which events happen At 8500 rpm the ECU has tocontrol 280 injector openings/closing per second and 280 ignition signals per second, whilecoping with 2400 signals from the distributor per second Plus there are another 16-odd signalsand sensor reading from the engine and outside world that ECU needs to know about

VTEC system is a simple and fairly elegant method of endowing the engine withmultiple camshaft profiles optimized for low and high RPM operations Instead of only one camlobe actuating each valve, there are two - one optimized for low RPM smoothness and one tomaximize high RPM power output Switching between the two cam lobes is controlled by theengine's management computer As the engine speed is increased, more air/fuel mixture needs to

be "inhaled" and "exhaled" by the engine Thus to sustain high engine speeds, the intake and

exhaust valves needs to open nice and wide As engine RPM increases, a locking pin is pushed

by oil pressure to bind the high RPM cam follower for operation From this point on, the valveopens and closes according to the high-speed profile, which opens the valve further and for alonger time

4.1 BASIC V-TEC MECHANISM

The basic mechanism used by the VTEC technology is a simple hydraulicallyactuated pin This pin is hydraulically pushed horizontally to link up adjacent rocker arms Aspring mechanism is used to return the pin back to its original position

To start on the basic principle, examine the simple diagram below It comprises acamshaft with two cam-lobes side-by-side These lobes drive two side-by-side valve rocker arms

The two cam/rocker pairs operates independently of each other One of the two cam-lobes are intentionally drawn to be different The one on the left has a "wilder" profile, it will open its valve earlier, open it more, and close it later, compared to the one on the right Under normal operation, each pair of cam-lobe/rocker-arm assembly will work independently of each other.

VTEC uses the pin actuation mechanism to link the mild-cam rocker arm to the wild-cam rocker arm This effectively makes the two rocker arms operate as one This "composite" rocker arm(s) now clearly follows the wild-cam profile of the left rocker arm This in essence is the basic working principle of all of Honda's VTEC engines.

VTEC, the original Honda variable valve control system, originated from REV(Revolution-modulated valve control) introduced on the CBR400 in 1983 known as HYPERVTEC In the regular four-stroke automobile engine, the intake and exhaust valves are actuated

by lobes on a camshaft The shape of the lobes determines the timing, lift and duration of eachvalve Timing refers to an angle measurement of when a valve is opened or closed with respect

to the piston position (BTDC or ATDC) Lift refers to how much the valve is opened Durationrefers to how long the valve is kept open Due to the behavior of the working fluid (air and fuelmixture) before and after combustion, which have physical limitations on their flow, as well astheir interaction with the ignition spark, the optimal valve timing, lift and duration settings underlow RPM engine operations are very different from those under high RPM Optimal low RPMvalve timing, lift and duration settings would result in insufficient filling of the cylinder with fueland air at high RPM, thus greatly limiting engine power output Conversely, optimal high RPMvalve timing, lift and duration settings would result in very rough low RPM operation anddifficult idling The ideal engine would have fully variable valve timing, lift and duration, inwhich the valves would always open at exactly the right point, lift high enough and stay openjust the right amount of time for the engine speed in use

BASIC VTEC PRINCIPLE

4.2 DOHC VTEC

Introduced as a DOHC (Double overhead camshaft) system in Japan in the 1989Honda Integra XSi this used the 160 bhp (120 kW) B16A engine The same year, Europe saw thearrival of VTEC in the Honda CRX 1.6i-VT, using a 150 bhp variant (B16A1) The UnitedStates market saw the first VTEC system with the introduction of the 1991 Acura NSX, whichused a 3-litre DOHC VTEC V6 with 270 bhp (200 kW) DOHC VTEC engines soon appeared inother vehicles, such as the 1992 Acura Integra GS-R (B17A1 1.7-litre engine), and later in the

1993 Honda Prelude VTEC (H22A 2.2-litre engine with 195 hp) and Honda Del Sol VTEC(B16A3 1.6-litre engine) The Integra Type R (1995–2000) available in the Japanese marketproduces 197 bhp (147 kW; 200 PS) using a B18C5 1.8-litre engine, producing more horsepowerper liter than most super-cars at the time Honda has also continued to develop other varietiesand today offers several varieties of VTEC, such as i-VTEC and i-VTEC Hybrid.

4.3 SOHC VTEC

As popularity and marketing value of the VTEC system grew, Honda applied the

system to SOHC (single overhead camshaft) engines, which share a common camshaft for both

intake and exhaust valves The trade-off was that Honda's SOHC engines benefitted from theVTEC mechanism only on the intake valves This is because VTEC requires a third center rockerarm and cam lobe (for each intake and exhaust side), and, in the SOHC engine, the spark plugsare situated between the two exhaust rocker arms, leaving no room for the VTEC rocker arm.Additionally, the center lobe on the camshaft cannot be utilized by both the intake and theexhaust, limiting the VTEC feature to one side

DOHC VTEC ENGINE MODEL