VTEC Technology
VTEC Engine (Found in 2005-2007 Jazz 1.5L and 2000-2007 City 1.5L)
It was a laborious process, one bordering on the mythical, but more than a decade ago, Honda shattered the engine myth when it combined high power, high responsiveness and high fuel economy into one functional engine design. The world has come to know this engine genius as VTEC or Variable Valve Timing and Lift Electronic Control.
The engine’s valve timing and lift largely determine its character. That is, the time at which the valves open and how long they remain open.
The VTEC engine broke technological barriers when it combined the best features of two engines in one. It revolutionized the way car engines were made when it employed two differently shaped cam lobes that switch between two different combustion settings within the same engine.
The VTEC engine has four valves per cylinder: two for intake and two for exhaust. Engine RPM causes the intake valves to switch between (large) high-profile cam lobes and (small) low-profile cam lobes.
The engine’s valve timing and lift largely determine its character. That is, the time at which the valves open and how long they remain open.
The VTEC engine broke technological barriers when it combined the best features of two engines in one. It revolutionized the way car engines were made when it employed two differently shaped cam lobes that switch between two different combustion settings within the same engine.
The VTEC engine has four valves per cylinder: two for intake and two for exhaust. Engine RPM causes the intake valves to switch between (large) high-profile cam lobes and (small) low-profile cam lobes.
VTEC 3 Engine (Found in 2001-2005 Civic 1.6L )
Honda Proves that an engine can be extremely powerful and fuel efficient at the same time - all it takes is innovative technology like Honda VTEC3 (Variable Valve Timing and Lift Electronic Control). The Civic power plant is available in three variations that deliver class-leading performance by way of precedent-setting features. Honda‘s powerful 1.6 liter engine generates quick acceleration via VTEC 3 (three-stage VTEC) - the breakthrough technology that boosts power and fuel efficiency by varying the behavior of the intake valves to match the needs of the engine. Also available are advanced 1.5 liter 16-valve engine. All these configurations drive 4-valves-per-cylinder through Honda‘s innovative single overhead camshaft (SOHC) design.
i-VTEC Engine (Found in 2002-2006 CR-V, 2004 Civic 2.0L and 2003-2007 Accord)
Once again, world leader in driving pleasures proves that an engine can be powerful, fuel efficient, and clean running at the same time. Now, Honda combines new VTC - the latest breakthrough in Variable Timing Control - with renowned VTEC innovation to achieve revolutionary i-VTEC performance. While VTEC electronically switches valve timing and valve lift to match low and high-speed ranges. VTC provides continuous phase control of the intake valve according to engine load rotation. This combination of advanced technologies creates and ideal balance of high power and fuel economy with effectual emission control - translating into pure performance.
New i-VTEC Engine (Found in current models: 2006 Civic, 2007 CR-V, 2008 Accord, 2008 Jazz & 2009 City)
Using the same intelligent VTEC system that switches the valve timing for maximum efficiency during startup and acceleration, the new 1.8-liter i-VTEC engine achieves powerful performance, and delays intake valve closure timing during cruising and other low-load conditions for more improved fuel economy.
With the new i-VTEC engine, intake valve closure timing is delayed to control the intake volume of the air-fuel mixture, allowing the throttle valve to remain wide open even under low-load conditions. This translates to a major reduction in pumping losses. Combined with comprehensive friction-reducing measures, this results in a significant increase in fuel efficiency for the engine. Even better, this new engine genius is lighter, shorter and quieter.
With the new i-VTEC engine, intake valve closure timing is delayed to control the intake volume of the air-fuel mixture, allowing the throttle valve to remain wide open even under low-load conditions. This translates to a major reduction in pumping losses. Combined with comprehensive friction-reducing measures, this results in a significant increase in fuel efficiency for the engine. Even better, this new engine genius is lighter, shorter and quieter.
i-DSI Engine (Found in 2003-2008 City 1.3L and 2004-2007 Jazz 1.3L )
Honda‘s intelligent Dual & Sequential Ignition (i-DSI) engine is the second i-Series engine, next to i-VTEC, that employs compact combustion chambers and two spark plugs per cylinder with individually controlled ignition timing for more rapid and complete combustion. Achieving best in its class high fuel economy, this new generation engine was developed exclusively for compact vehicles.
VCM643 Engine (Found in 2008 Accord 3.5)
Variable Cylinder Management™ (VCM®) technology maintains power and optimizes fuel economy simultaneously. It activates the engine’s cylinders as needed to meet the demands of both acceleration and fuel efficiency. At 6 cylinder mode, the engine produces an exhilarating kick with its powerful V6 engine, while at 4 cylinder mode, it produces both power and fuel efficiency. And at 3 cylinder mode, fuel saving is achieved.
The i-VTEC Variable Cylinder Management™ system enables the engine to switch between six, four and three cylinder operation.
While the engine is under light load such as moderate acceleration or steady cruising, it deactivates cylinders #3 and #4 in both front and rear banks, running the engine with the remaining four cylinders.
And during low speed cruising and descending, the #'s 1, 2 and 3 cylinders in the rear bank are deactivated maintaining 3 cylinders running the engine. This 6-4-3 process improves the overall fuel economy while maintaining the high power output expected from a V6 engine.
The i-VTEC Variable Cylinder Management™ system enables the engine to switch between six, four and three cylinder operation.
While the engine is under light load such as moderate acceleration or steady cruising, it deactivates cylinders #3 and #4 in both front and rear banks, running the engine with the remaining four cylinders.
And during low speed cruising and descending, the #'s 1, 2 and 3 cylinders in the rear bank are deactivated maintaining 3 cylinders running the engine. This 6-4-3 process improves the overall fuel economy while maintaining the high power output expected from a V6 engine.
Source: Honda Philippines