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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
EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec “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 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec GOVERNMENT POLYTECHNIC AURANGABAD C E RT I FI CAT 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 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 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 and support 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) EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec i-VTEC ENGINE ABSTRACT EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 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 (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 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 Honda's i-VTEC technology gives us the best in vehicle performance EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec INDEX SR.N O TOPIC NAME INTODUCTION OBJECTIVE TERMS RELATED TO i-VTEC VTEC 13 4.1 Basic VTEC Mechanism 4.2 DOHC VTEC 4.3 SOHC VTEC 4.4 3-Stage VTEC VALVE TIMING CONTROL (VTC) i-VTEC SYSTEM ADVANTAGES OF i-VTEC SYSTEM DISADVANTAGES OF i-VTEC APPLICATIONS OF i-VTEC SYSTEM CASE STUDY OF ‘HINDA CITY’ 10 1 27 11.1 Pneumatic Valve 11.2 VTEC in Turbo 11.3 i-VTEC in Motorcycle TOP 10 i-VTEC ENGINES 12 19 20 23 23 24 25 10.1 Specifications OF i-VTEC Engine 10.2 Performance FUTURE TRENDS 11 08 09 11 3.1 Volumetric Efficiency 3.2 Torque 3.3 Power 3.4 Camshaft 3.6 Engine Breathing 3.7 Electronic Control Unit (ECU) PAGE NO 28 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 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 12.9 K24A2 13 14 CONCLUSION REFERANCE 30 31 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 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 is considered 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 few development of rotary combustion engine the IC engines has still retained its basic anatomy As our knowledge of engine processes has increased, these engines have continued to develop on a scientific basis The present day engines have advances to satisfy the strict environmental constraints and fuel economy standards in addition to meeting in competitiveness of the world market With the availability of sophisticated computer and electronic, instrumentation have added new refinement to the engine design From the past few decades, automobile industry has implemented many advance technologies to improve the efficiency and fuel economy of the vehicle and i-VTEC engine introduced by Honda in its 2002 Acura RSX Type S is one of such recent trend in automobile industry The VTEC system provides the engine with multiple cam lobe profiles optimized for both low and high RPM operations In basic form, the single barring shaft-lock of a conventional engine 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 between the two cam lobes is controlled by the ECU which takes account of engine oil pressure, engine temperature, vehicle speed, engine speed and throttle position Using these inputs, the ECU is programmed to switch from the low lift to the high lift cam lobes when the conditions mean that engine output will be improved At the switch point a solenoid is actuated which allows oil pressure from a spool valve to operate a locking pin which binds the high RPM cam follower to the low RPM ones From this point on, the valves open and close according to the high-lift profile, which opens the valve further and for a longer time EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 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 10 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 4.5 THREE STAGES OF ACTUATION OF VALVES 3-Stage VTEC is a version that employs three different cam profiles to control intake valve timing and lift Due to this version of VTEC being designed around a SOHC valve head, space was limited and so VTEC can only modify the opening and closing of the intake valves The low-end fuel economy improvements of VTEC-E and the performance of conventional VTEC are combined in this application From idle to 2500-3000 RPM, depending on load conditions, one intake valve fully opens while the other opens just slightly, enough to prevent pooling of fuel behind the valve, also called 12-valve mode This 12 Valve mode results in swirl of the intake charge which increases combustion efficiency, resulting in improved low end torque and better fuel economy At 3000-5400 RPM, depending on load, one of the VTEC solenoids engages, which causes the second valve to lock onto the first valve's camshaft lobe Also called 4-valve mode, this method resembles a normal engine operating mode and improves the mid-range power curve At 5500-7000 RPM, the second VTEC solenoid engages (both solenoids now engaged) so that both intake valves are using a middle, third camshaft lobe The third lobe is tuned for high-performance and provides peak power at the top end of the RPM range Vtec system which combines the standard Vtec and Vtec-e concepts to create a high power, fuel efficient valve train Utilizes separate Camshaft Profiles This system operates like Vtec-e closing one valve at low speeds and then opening both valves at a standard lift and duration at a midrange rpm It then has a high rpm cam which opens both valves aggressively as in standard Vtec Like standard Vtec one rocker arm, usually on the highest lift profile, is not attached to a valve so that the highest lift is only used when the system is in operational Vtec range In the illustration below the three significant camshaft profiles can be seen And the sliding pins for each stage are shown as well 18 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 19 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec VARIABLE TIMING CONTROL (VTC): VTC operating principle is basically that of the generic variable valve timing implementation (this generic implementation is also used by Toyota in their VVT-i and BMW in their VANOS/double-VANOS system) The generic variable valve timing implementation makes use of a mechanism attached between the cam sprocket and the camshaft This mechanism has a helical gear link to the sprocket and can be moved relative the sprocket via hydraulic means When moved, the helical gearing effectively rotates the gear in relation to the sprocket and thus the camshaft as well VTC PRICIPLE The drawing above serves to illustrate the basic operating principle of VTC (and generic variable valve timing) A labels the cam sprocket (or cam gear) which the timing belt drives Normally the camshaft is bolted directly to the sprocket However in VTC, an intermediate gear is used to connect the sprocket to the camshaft This gear, labeled B has helical gears on its outside As shown in the drawing, this gear links to the main sprocket which has matching helical gears on the inside The cam shaft, labeled C attaches to the intermediate gear The supplementary diagram on the right shows what happens when we move the intermediate gear along its holder in the cam sprocket Because of the interlinking helical gears, the intermediate gear will rotate along its axis if moved Now, since the camshaft is attached to this gear, the camshaft will rotate on its axis too What we have achieved now is that we have move the relative alignment between the camshaft and the driving cam-sprocket - we have changed the cam timing! i-VTEC SYSTEM: 20 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 6.1 i-VTEC SYSTEM LAYOUT Diagram explains the layout of the various components implementing i-VTEC I have intentionally edited the original diagram very slightly - the lines identifying the VTC components are rather faint and their orientation confusing I have overlaid them with red lines They identify the VTC actuator as well as the oil pressure solenoid valve, both attached to the intake camshaft's sprocket The VTC cam sensor is required by the ECU to determine the current timing of the intake camshaft The VTEC mechanism on the intake cam remains essentially the same as those in the current DOHC VTEC engines except for an implementation of VTEC-E for the 'mild' cam 21 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 6.2 VALVE ACTUATION DIAGRAM The diagrams show that VTEC is implemented only on the intake cam Now, note that there is an annotation indicating a 'mostly resting (intake) cam' in variations to This is the 'approximately 1-valve' operating principle of VTEC-E I.e one intake valve is hardly driven while the other opens in its full glory This instills a swirl effect on the air-flow which helps in air-fuel mixture and allows the use of the crazy 20+ to air-to-fuel ratio in leanburn or economy mode during idle running conditions On first acquaintance, variations and seem identical However, in reality they represent two different engine configurations - electronic-wise Variation is lean burn mode, the state in which the ECU uses >20:1 air-fuel ratio VTC closes the intake/exhaust valve overlap to a minimal Note that lean-burn mode or variation is used only for very light throttle operations as identified by the full load Torque curve overlaid on the VTC/RPM graph During heavy throttle runs, the ECU goes into variation Lean-burn mode is contained within variation-2 as a dotted area probably for the reason that the ECU bounces toand-fro between the two modes depending on engine rpm, throttle pressure and engine load, just like the 3-stage VTEC D15B and D17A In variation-2, the ECU pops out of lean-burn mode, goes back to 14.7 or 12 to air-fuel ratios and brings the intake/exhaust overlap right up to maximum This as Honda explains will induce the EGR effect, which makes use of exhaust gases to reduce emissions Variation-3 is the mode where the ECU varies intake/exhaust-opening overlap dynamically based on engine rpm for heavy throttle runs but low engine revs Note also that variations to are used in what Honda loosely terms the idle rpm For 3-stage VTEC engines, idle rpms take on a much broader meaning It is no longer the steady 750rpm or so for an engine at rest For 3-stage VTEC, idle rpm also means low running rpm during ideal operating conditions, i.e closed or very narrow throttle positions, flat even roads, steady speed, etc It is an idle rpm range The K20A engine implements this as well 22 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 6.3 ACTUATION OF HIGH SPEED CAM Variation-4 is activated whenever rpm rises and throttle pressure increases, indicating a sense of urgency as conveyed by the driver's right foot This mode sees the wild cams of the intake camshaft being activated, the engine goes into 16-valve mode now and VTC dynamically varies the intake camshaft to provide optimum intake/exhaust valve overlap for power On i-VTEC engines, the engine computer also monitors cam position, intake manifold pressure, and engine rpm, then commands the VTC (variable timing control) actuator to advance or retard the cam At idle, the intake cam is almost fully retarded to deliver a stable idle and reduce oxides of nitrogen (NOX) emissions The intake cam is progressively advanced as rpm builds, so the intake valves open sooner and valve overlap increases This reduces pumping losses, increasing fuel economy while further reducing exhaust emissions due to the creation of an internal exhaust gas recirculation (EGR) effect i-VTEC introduced continuously variable timing, which allowed it to have more than two profiles for timing and lift, which was the limitation of previous systems The valve lift is still a 2-stage setup as before, but the camshaft is now rotated via hydraulic control to advance or retard valve timing The effect is further optimization of torque output, especially at low RPMs Increased performance is one advantage of the i-VTEC system The torque curve is "flatter" and does not exhibit any dips in torque that previous VTEC engines had without variable camshaft timing Horsepower output is up, but so is fuel economy Optimizing combustion with high swirl induction makes these engines even more efficient Finally, one unnoticed but major advantage of i-VTEC is the reduction in engine emissions High swirl intake and better combustion allows more precise air-fuel ratio control This results in substantially reduced emissions, particularly NOx Variable control of camshaft timing has allowed Honda to eliminate the EGR system Exhaust gases are now retained in the cylinder when necessary by changing camshaft timing This also reduces emissions without hindering performance 23 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec ADVANTAGES OF i-VTEC: 1) 2) 3) 4) Better Fuel Efficiency High initial torque and relevant high power Lower emission Strong performance DISADVANRAGES OF i-VTEC: 1) Cost is high 2) Available in Honda Models only 24 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec APPLICATIONS Currently i-VTEC technology is available In Honda products; 1) 2) 3) 4) 5) 6) Honda CRV Honda CITY Honda Civic Honda Amaze Honda Mobilio Honda Accord 25 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 10 CASE STUDY OF ‘HONDA CITY’: The new i- VTEC system in Honda CITY 2006 uses its valve timing control system to deliver acceleration performance equivalent to a 2.0-liter engine and fuel economy approximately 6% better than the current 1.7-literCITY engine During cruising, the new engine achieves fuel economy equivalent to that of a 1.5-liter engine In a conventional engine, the throttle valve is normally partly closed under low-load conditions to control the intake volume of the fuel-air mixture During this time, pumping losses are incurred due to intake resistance, and this is one factor that leads to reduced engine efficiency The i-VTEC engine delays intake valve closure timing to control the intake volume of the air-fuel mixture, allowing the throttle valve to remain wide open even under low-load conditions for a major reduction in pumping losses of up to 16% Combined with friction-reducing measures, these results in an increase in fuel efficiency for the engine itself A DBW (Drive by Wire) system provides high-precision control over the throttle valve while the valve timing is being changed over, delivering smooth driving performance that leaves the driver unaware of any torque fluctuations Other innovations in the new VTEC include a variable-length intake manifold to further improve intake efficiency and piston oil jets that cool the pistons to suppress engine knock In addition, lower block construction resulting in a more rigid engine frame, aluminum rocker arms, high-strength cracked connecting rods, a narrow, silent cam chain, and other innovations make the engine more compact and lightweight It is both lighter and shorter overall than the current CITY 1.7-liter engine, and quieter as well 26 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 10.1 SPECIFICATIONS OF i-VTEC ENGINE: Engine type and number of cylinders Displacement Max power / rpm Torque / rpm Compression ratio Water-cooled in-line 4-cylinder 1,799 cc 103 kW (138 hp)/ 6300 174 Nm (128 lb-ft)/4300 10.5:1 10.2 GRAPH SHOVING THE PERFORMANCE AS SPEED VS TORQUE 10.2 PERFORMANCE: This new engine utilizes Honda's "VTEC" technology, which adjusts valve timing and lift based on the engine's RPM, but adds "VTC" - Variable Timing Control - which continuously modulates the intake valve overlap depending on engine load The two combined yield in a highly intelligent valve timing and lift mechanism In addition to such technology, improvements in the intake manifold, rearward exhaust system, lean-burn-optimized catalytic converter help to create an engine that outputs 103kW (140PS) @ 6300rpm,and provides ample mid-range torque It also satisfies the year 2010 fuel efficiency standard of14.2km/Land receives the government standard of "LEV” 11 FUTURE TRENDS: 11.1 Pneumatic Valves 27 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec The valve spring pocket is replaced with a chamber pressurized with a gas (usually nitrogen because it is less temperature-sensitive than O2) Still use traditional camshafts The system has been used in Formula racing since 1980s Allows higher RPMs – valve springs have to be very stiff to allow high RPMs which creates more engine drag and slower valve timing BASIC CONCEPT OF PENUMATIC VALVE IN i-VTEC 11.2 VTEC TURBO The VTEC TURBO engine series included gasoline direct-injection, turbocharger, variable valve motion technology such as VTEC The engines were introduced in 19-Nov-2013 as part of the Earth Dreams Technology range, which included displacement capacities (1 liter 3-cylinder, 1.5 litre4-cylinders, liter 4-cylinder) Initial implementation for European vehicles included 2-litre 4-cylinder engine used in Honda Civic Type R, which included Euro emissions compliance 11.3 VTEC IN MOTORCYCLE Apart from the Japanese market-only Honda CB400SF Super Four HYPER VTEC, introduced in 1999, the first worldwide implementation of VTEC technology in a motorcycle occurred with the introduction of Honda's VFR800 sport bike in 2002 Similar to the SOHC VTEC-E style, one intake valve remains closed until a threshold of 7000 RPM is reached, and then the second valve is opened by an oil-pressure actuated pin The dwell of the valves remains unchanged, as in the automobile VTEC-E, and little extra power is produced, but with a smoothing-out of the torque curve Critics maintain that VTEC adds little to the VFR experience, while increasing the engine's complexity Honda seemed to agree, as their VFR1200, a model announced in October 2009, came to replace the VFR800, which abandons the V-TEC concept in favor of a large capacity narrow-vee"unicam", i.e., SOHC, engine However, the 2015 VFR800 will again sport the same VTEC system of the 2002-2009 VFR motorcycle Honda incorporated the technology into the NC700 series, including the NC700D Integra, released in 2012, using a single camshaft to provide two timing routines for the intake valves 12 TOP 10 i-VTEC ENGINES: 28 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec If you're thinking of picking up your first Honda project or are ready to pull the trigger on a swap and can't decide which engine is going to be right for you, then check out this quick, basic guide to some of the best options available i B16A Origin: 1989-1993 JDM Integra XSi, RSi; 1989-1991 JDM Civic/CRX SiR Horsepower/Torque: 160hp/112lb-ft But why?: It's the first DOHC VTEC engine that you could afford ii B16B Type R Origin: 1997-2000 JDM Civic Type R Horsepower/Torque: 185hp/118lb-ft But why?: A de-stroked version of Honda's B18C, the B16B boasts an amazing, high-RPM friendly rod/stroke ratio iii B18C1 Origin: 1994-2001 Integra GS-R Horsepower/Torque: 170hp/128lb-ft But why?: The B18C1 was Honda's first 1.8L VTEC engine and the first production engine to feature a dual-stage intake manifold iv B18C Type R Origin: 1995-2001 JDM Integra Type R Horsepower/Torque: 200hp/137lb-ft But why?: It's Honda's most powerful B-series What's not to like? v C32B Type R Origin: 2002-2005 JDM NSX-R Horsepower/Torque: 290hp/224lb-ft But why?: A meticulously balanced and blueprinted version of Honda's standard NSX engine, the Type R isn't just expensive, it's also nearly impossible to source vi F20C1 Origin: 2000-2005 S2000 Horsepower/Torque: 240 hp/153lb-ft But why?: Considered by many to be Honda's most impressive four-cylinder to date, the F20C1 features amazing RPM capabilities without sacrificing mid-range power vii H22A1 Origin: 1993-1996 Prelude VTEC Horsepower/Torque: 190hp/158lb-ft 29 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec But why?: Honda's first big-block engine, the H22A1 helped secure a number of drag racing records and went on to make Honda history viii J37A4 Origin: 2009-2013 TL SH-AWD Horsepower/Torque: 305hp/273lb-ft But why?: It's Honda's most powerful production engine to date What more you want? ix K20A Type R Origin: 2001-2005 Civic Type R and Integra Type R Horsepower/Torque: 212hp/149lb-ft But why?: At 212hp, it's the top-of-the-line K-series for engine swappers x K24A2 Origin: 2004-2008 TSX Horsepower/Torque: 205hp/164lb-ft 30 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 13 CONCLUSION: i-VTEC system is more sophisticated than earlier variable-valve-timing systems, which could only change the time both valves are open during the intake/exhaust overlap period on the transition between the exhaust and induction strokes By contrast, the i-VTEC setup can alter both camshaft duration and valve lift i-VTEC Technology gives us the best in vehicle performance Fuel economy is increased, emissions are reduced, derivability is enhanced and power is improved 31 EBOOKBKMT.COM – Vietnam M&E Technology Community i-vtec 14 REFERANCES: a b c d e f g h i j k l m Deccan Honda, Service Centre, Waluj Aurangabad Mr Santosh Gade (service manager Deccan Honda) Mr Bodkhe Sir (worker) Wikipedia, (www.wikipedia.com/ivtec) Street Magazine, (www.streetmagazine.com) Delphi Variable Cam Phases 2014 May 2014 http://www.delphi.com/manufacturers/auto/powertrain/gas/valvetrain/vcp/ VANOS 2007 May 2007 http://www.bmw.dk/teknisk/en_artikkel.asp?id=5 Different Types of VVT 2005 May 2014 http://www.autozine.org/technical_school/engine/vvt_2.htm Honda Worldwide 2014 May 2014 http://world.honda.com/motorcycletechnology/vtec/img/p3_04.jpg VTEC 2014 May 2014 http://www.luk-korbmacher.de/Autos/Technik/vtec.htm BMW Valvetronic 2014 May 2014 http://youtube.com/watch?v=rEELtXVTymU 32 ... for intelligent: i- VTEC is intelligent -VTEC Honda introduced many new innovations in iVTEC, but the most significant one is the addition of a variable valve opening overlap mechanism to the VTEC. .. capacities (1 liter 3-cylinder, 1.5 litre4-cylinders, liter 4-cylinder) Initial implementation for European vehicles included 2-litre 4-cylinder engine used in Honda Civic Type R, which included... Community i- vtec 6.1 i- VTEC SYSTEM LAYOUT Diagram explains the layout of the various components implementing i- VTEC I have intentionally edited the original diagram very slightly - the lines identifying