The desmodromic valve engine, widely used by Ducati, uses cams and levers to close its valves in place of what conventional mechanism?
Ducati 749 The Ducati 749 is a 90° V-twin Desmodromic valve actuated engine sport bike built by Ducati Motor Holding between 2003 and 2006. Designed by Pierre Terblanche, the 749 was available as the 749, 749 Dark, 749S, and 749R. It shared many of its parts with the 999, with the exception of a slightly smaller 180/55 profile rear tire, smaller cylinders, and different cylinder heads, giving it a smaller displacement of 748 cc. This smaller engine is higher revving and produces a lower peak horsepower than the larger engine used in the 999. The 749S model, like the 999, incorporates features rarely found on production motorcycles, including adjustable rake (23.5° or 24.5°) and five-position adjustable rearset mounts.
Volvo SI6 engine Volvo designed the SI6 ("short inline 6") straight-6 automobile engine for use in 2007 models. An evolution of the company's long-used straight-5 Volvo Modular engine, which itself is an evolution of the Volvo B6304 straight six engine, the SI6 can be mounted transversely for front wheel drive or all wheel drive applications. Despite the added cylinder and displacement, the engine remains compact, and is in fact 1 mm shorter than the previous straight-5. The engine was initially offered in two displacements — a 3.0 L turbocharged version and a 3.2 L naturally aspirated version. Both offered variable cam timing, though only the turbo version varies both the intake and exhaust valves. On top of the variable cam timing used on the intake cam of the naturally aspirated engine it also had variable valve lift by using Cam Profile Switching (CPS).