The i-Vtech technology is a part or further Invansion of VTEC Technology.
Before seeing i-vtec first let us see what is VTEC is ?
Now first Let us see What is actually VTEC Technolgy.
VTEC stands for (Variable Valve Timing Engine Control) is Valvetrain system developed by Honda to (Improve the Volumetric Efficency) of four Stroke Engine.
HISTORY
It was developed by Honda & originated from REV (Revolution modulated
Valve Control). Which was used on the (CBR 400) in 1983 known as
HYPER VTEC.
VTEC was initially designed to Increase the power output of an
Engine to 100Hp/Litre or more while maintaining practically for use in mass
production Vehicles.After some time the designed also improves fuel efficency.
The VTEC system provides the Engine with multiple CamShaft
for both low & high RPM operation. The operation between two Cam lobes
is controlled by the ECU.
DOHC Engine
DOHC stands for (Double Overhead Cam) was first Introduced in
Japan in 1989 Honda Integra XSi.
DOHC has 2 Cams for Intape of air-fuel mixture & 2 cams for
exhaust to flow out of the cylinder for more free flow & greater power.
SOHC Engine
Seeing the popularity & market value of V-TEC system grew,Honda applied the system to SOHC( single overhead cam) engines which share a common camshaft for both intake & exhaust valves.
-> SOHC VTEC was incorporated for use with intake & exhaust valves;The Intake & Exhaust rocker shafts contains primary & Secondary intake & exhaust rockler arms.
->The "PRIMARY ROCKER" arm contains the VTEC switching piston.While the Secondary rocker arm contains the return spring.
NOTE:The term "PRIMARY" does not refer to which refer to which rocker arm forces the valve down during the low-RPMs engine operation.Rather,It refers to the Rocker arm which contains the VTEC switching piston & recevies oil from the rocker from the rocker shaft.
->Since seeing the diffculty of Incorporating VTEC it is removed from both the Intake & Exhaust.
(FOR BETTER UNDERSTANDING OF VTEC REFER TO VIDEO ATTACHED)
VTEC-E
VTEC-E is a variation of SOHC VTEC which was used to Increase efficiency at low-RPM.At low RPM,one of the two intake valves is only allowed to open a very small amount,increasing the fuel/air atomization in the cylinder & thus allowing a leaner mixture to be used.
i-VTEC
(NOTE:its operation is also similar to an Atkinson cycle engine, with uneven compression and combustion strokes)
-> i-vtec (INTELLIGENT VARIABLE VALVE TIMING ENGINE CONTROL) has VTC continously variable timing of cam shaft of DOHC VTEC engines.
-> This technology first appeared on Honda's K-series four-cylinder engine family in 2001.
->VTC controls of valve lift & valve duration are still limited to distinct low & high RPM profiles but the intake camshaft is now capable of advancing between 25 & 50 degrees, This is control & is implemented by a computer,oil driven adjustable cam gear.
In i-VTEC see K-series engine
The K-series is used for both
1.PERFORMANCE MOTORS (power providing vechiles) like RSX type or the CIVIC SI.
NOTE: " The performance i-VTEC system is basically the same as the DOHC VTEC system of the B16 A's both intake & exhaust have 3 cam lobes per cylinder & the valvetrain has the added benefit of roller rockers & continuously variable intake cam timing."
2.ECONOMY MOTORS such as CR-v or ACCORD.
NOTE:" The economy i-VTEC is more like the SOHC VTEC-E in that the intake cam has only two lobes,one smaller & one larger, & does not have VTEC on the exhaust cam"
(FOR BETTER UNDERSTANDING OF i- VTEC REFER TO VIDEO ATTACHED)
i-VTEC WITH VARIABLE CYLINDER MANAGEMENT (VCM)
-> In 2003,Honda introduced an i-VTEC V6 that includes Honda's cylinder deactivation technology which closes the valves of cylinder during light load & low speed below 80KM/H.
->According to Honda,"VCM technology works on the principle that a Vehicle only requires a fraction of its power output at CRUISING SPEED("The most fuel efficient speed on which car runs)
->The system electronically deactivates cylinder to reduce fuel consumption.
i-VTEC i
->It is a version of i-VTEC with direct-injection.
->It uses very lean mixture during combustion in low RPM.
->One of the two intake values is remained closed at engine at low RPM.
->VTC(variable timing control system) helps in maintaining the perfect environment during combustion during low RPM.
->THe air fuel mixture here is 65:1.
->Increases 20% to engine efficiency.
->At,high load condition or at high RPMs the both valves get opened to provide rich mixture.
(FOR BETTER UNDERSTANDING OF i- VTEC i REFER TO VIDEO ATTACHED)
Before seeing i-vtec first let us see what is VTEC is ?
Now first Let us see What is actually VTEC Technolgy.
VTEC stands for (Variable Valve Timing Engine Control) is Valvetrain system developed by Honda to (Improve the Volumetric Efficency) of four Stroke Engine.
HISTORY
It was developed by Honda & originated from REV (Revolution modulated
Valve Control). Which was used on the (CBR 400) in 1983 known as
HYPER VTEC.
VTEC was initially designed to Increase the power output of an
Engine to 100Hp/Litre or more while maintaining practically for use in mass
production Vehicles.After some time the designed also improves fuel efficency.
The VTEC system provides the Engine with multiple CamShaft
for both low & high RPM operation. The operation between two Cam lobes
is controlled by the ECU.
DOHC Engine
DOHC stands for (Double Overhead Cam) was first Introduced in
Japan in 1989 Honda Integra XSi.
DOHC has 2 Cams for Intape of air-fuel mixture & 2 cams for
exhaust to flow out of the cylinder for more free flow & greater power.
SOHC Engine
Seeing the popularity & market value of V-TEC system grew,Honda applied the system to SOHC( single overhead cam) engines which share a common camshaft for both intake & exhaust valves.
-> SOHC VTEC was incorporated for use with intake & exhaust valves;The Intake & Exhaust rocker shafts contains primary & Secondary intake & exhaust rockler arms.
->The "PRIMARY ROCKER" arm contains the VTEC switching piston.While the Secondary rocker arm contains the return spring.
NOTE:The term "PRIMARY" does not refer to which refer to which rocker arm forces the valve down during the low-RPMs engine operation.Rather,It refers to the Rocker arm which contains the VTEC switching piston & recevies oil from the rocker from the rocker shaft.
->Since seeing the diffculty of Incorporating VTEC it is removed from both the Intake & Exhaust.
(FOR BETTER UNDERSTANDING OF VTEC REFER TO VIDEO ATTACHED)
VTEC-E
VTEC-E is a variation of SOHC VTEC which was used to Increase efficiency at low-RPM.At low RPM,one of the two intake valves is only allowed to open a very small amount,increasing the fuel/air atomization in the cylinder & thus allowing a leaner mixture to be used.
i-VTEC
(NOTE:its operation is also similar to an Atkinson cycle engine, with uneven compression and combustion strokes)
-> i-vtec (INTELLIGENT VARIABLE VALVE TIMING ENGINE CONTROL) has VTC continously variable timing of cam shaft of DOHC VTEC engines.
-> This technology first appeared on Honda's K-series four-cylinder engine family in 2001.
->VTC controls of valve lift & valve duration are still limited to distinct low & high RPM profiles but the intake camshaft is now capable of advancing between 25 & 50 degrees, This is control & is implemented by a computer,oil driven adjustable cam gear.
In i-VTEC see K-series engine
The K-series is used for both
1.PERFORMANCE MOTORS (power providing vechiles) like RSX type or the CIVIC SI.
NOTE: " The performance i-VTEC system is basically the same as the DOHC VTEC system of the B16 A's both intake & exhaust have 3 cam lobes per cylinder & the valvetrain has the added benefit of roller rockers & continuously variable intake cam timing."
2.ECONOMY MOTORS such as CR-v or ACCORD.
NOTE:" The economy i-VTEC is more like the SOHC VTEC-E in that the intake cam has only two lobes,one smaller & one larger, & does not have VTEC on the exhaust cam"
(FOR BETTER UNDERSTANDING OF i- VTEC REFER TO VIDEO ATTACHED)
i-VTEC WITH VARIABLE CYLINDER MANAGEMENT (VCM)
-> In 2003,Honda introduced an i-VTEC V6 that includes Honda's cylinder deactivation technology which closes the valves of cylinder during light load & low speed below 80KM/H.
->According to Honda,"VCM technology works on the principle that a Vehicle only requires a fraction of its power output at CRUISING SPEED("The most fuel efficient speed on which car runs)
->The system electronically deactivates cylinder to reduce fuel consumption.
i-VTEC i
->It is a version of i-VTEC with direct-injection.
->It uses very lean mixture during combustion in low RPM.
->One of the two intake values is remained closed at engine at low RPM.
->VTC(variable timing control system) helps in maintaining the perfect environment during combustion during low RPM.
->THe air fuel mixture here is 65:1.
->Increases 20% to engine efficiency.
->At,high load condition or at high RPMs the both valves get opened to provide rich mixture.
(FOR BETTER UNDERSTANDING OF i- VTEC i REFER TO VIDEO ATTACHED)
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