Engineering Explained brings us yet another great lesson on the art of automotive engineering. In this one, the lesson is on Variable Valve Lift vs Variable Valve Timing. To help explain this, the guest is Charles the humble mechanic who brought some Audi parts in order to help explain this. The parts are camshafts and a cam bridge out of a 09 Audi. This is almost the exact same setup that you`ll find in the 15 and up mark 7 GTI`S. There is the exhaust cam with variable valve lift and the other hand there is an intake cam with variable valve timing.
To be more precise, they are doing this on a 2009 2.0L L4 Turbo Audi engine. The Variable Valve Lift (VVL) is used to boost performance. However, it all depends on the load and RPM. The Variable Valve Timing (VVT) is usually used for controlling emissions. It lowers the combustion temperatures and this results in reducing NOx. However, the VVT can also have efficiency and performance benefits as well. You`ll be amazed to see how much engineering goes only for emissions purposes. Totally understandable if you want to breathe clean air. Check out the video below and learn everything there is about these two types of camshafts.
More valve problems? Here are radiator valves explained for you!