Powder Metallurgy parts used in Auto-Ⅱ

In internal combustion engines, variable valve timing (VVT) is the process of altering the timing of a valve lift event, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with variable valve lift systems. There are many ways in which this can be achieved, ranging from mechanical devices to electro-hydraulic and camless systems. Increasingly strict emissions regulations are causing[citation needed] many automotive manufacturers to use VVT systems.

Two-stroke engines use a power valve system to get similar results to VVT.

In 1980,Alfa Romeo was first time to use use VVT technology’in 1989,Honda use VVT technology at the first time;in 2001,BMW was the first time to use VVT technology to replace traditional throttle valve.

About this technology,different companies have different name,for example,like Toyota called VVT-i,Honda called VTEC and i-VTEC,Mitsubishi called MIVEC....Japanese cars always called CVVT,EU&US always called VCT etc.all of them are similar technology but different name.The actuator of VVT or VCT system is critical parts in cam phaser,like sprocket,housing,rotors and cover plate(below pictures for reference),most of them are using Powder metallurgy process to make..