Variable Valve Timing Mechanism on Toyota

Uploaded by Toyota Vios Club Indonesia. Courtesy of PT. Toyota Astra Motor, Indonesia.

Category:

Autos & Vehicles

Tags:

• VVT-i
• VVTi
• Toyota
• Vios
• TVCI
• TAM

[NSX00000]

VVT-i is just overlapping valve timing. It has nothing to valve lift like VTEC. The valve-lift stays the same. Dual VVT-i means that both the intake cam pulley and the exhaust pulley have the variable timing controller on them. VVTL-i is the one that is similar to VTEC wich involves valve-timing lift control. i-VTEC is the new breed from Honda which involves both the regular VTEC and the variable valve timing controller on the cam pulley which is similar to Toyota VVT-i.

[NorwegianCrows]

Rotary engines and Wankel engines are great, but have a lack of torque.

[alexisgt90]

@NorwegianCrows cool thakyou for the information i really needed that..im stuying mechanic class and that helps me :) THX

[NorwegianCrows]

@alexisgt90 Actually, theres lots of different types of rotary engines: The Liquidpiston engine The Sarich orbital engine The RKM engine (RotationsKolbenMaschine) The Trochilic engine The Engineair engine The Rand cam engine The Ramgen Integrated Supersonic Component Engine The original Atkinson cycle engine The Wave disk engine (From Wikipedia) They still have a lack of torque.

[alexisgt90]

@NorwegianCrows ummmm..dude wankel engines and rotary engines are the same thing the rotary engine is called wankel cuz the one who invented the engine was called felix wankel...im saying just in case you dont know..i just want to help :)

[MrGeckolizard]

@bulldozer313 No, it adjusts the duration of the valve openings to create a more efficient combustion.

[bulldozer313]

isn't this like an EGR valve?

[BreakFreeze]

VVT-i is adjustable valve timing by adjustable cam pulley at certain degree

[BreakFreeze]

VVT-i is not an exhaust recirculating system..also not the overlapping valve timing..all reciprocating engine model in this world got the valve overlapping system, the main purpose is to remove all exhaust gasses from cylinder, during overlapping, both exh & intake is opened, in this position, especially for turbo engine, intake pressure will blow all remaining exh gasses out from cylinder..for NA engine, light pressure will do the same, to improve combustion efficiency.

[jsaulgodoy]

I HAVE TOYOTAS FIRST VVTI......ITS CALLED T-VIS LOL

[valetdabess]

so on a VVT-i does the valve time change once i go over a certain amout of rpm or does it change depending on how far i depress the throtle?

[mistameanor420]

@fatqwert200 its operating as an "Exhaust Gas Recirculation"

In light load, cruising conditions it recirculates exhaust gas into the intake. The exhaust gas is inert and takes up space in the combustion chamber diluting the a/f mix. This slows the flame front in the cylinder, reducing cylinder temperature up to 300F reducing the emission of NOx, which is produced in high heat. Also, fuel is reduced in these situations, improving fuel economy.