How long until we get rid of the camshaft?

[Old Tele man]

...the "i" in VVTi ...for intellegent.

[tjts1]

Originally Posted by Rokeby

I guess hydralics are out of the running... too slow/complicated?

See the first video. Also most VVT systems rely on hydraulics for adjustment.

[sendler]

Agreed. I have been a fan of the BMW valvetronic system and it is a step forward though it is only offered on their biggest engines? Multi air looks very flexible and should actually accomplish most of what I was looking for. Is any car maker using it? These are both "brute force mechanical" solutions but pretty effective. Keep in mind when considering the magnetic demands of an electronic valve train that the magnetics could be employed to move the valves in both directions with infinite control range of the available acceleration. The valves could move very quickly through most of the range of motion without slamming at either end. And only a very light helper spring would be needed as a fail safe and modern valves themselves are very light. Complete computer control of valve timing with Multi air or similar magnetic system along with direct injection will bring a quantum leap forward in broadening the sweet spot on the BSFC map in both aspects of rpm and load. Load almost becomes an obsolete term being replaced by percentage of maximum request in an engine with no throttle plate.

[Old Mechanic]

My original patent application in 2004 was for an engine with no valves, no connecting rods, and no crankshaft. It was variable displacement and compression. Two cycle with supercharging. 3 actual cycles, combustion, exchange, compression. Similar in operation to a Detroit Diesel with direct injection of preheated supercritical fuel. Injectors were operated by the engines rotation with lobes on the hub that worked the injectors mechanically with a fixed volume of delivery and the ability to completely destroke itself and become a flywheel to provide short term storage of energy and pulse a glide capability with a CVT at constant speeds.

I have the rejection letter from the Department of Energy comapring it to a Wankel. The letter was submitted by then US Senator George Allen's (Va) office.

Morons.

regards
Mech

[tjts1]

Originally Posted by sendler

Agreed. I have been a fan of the BMW valvetronic system and it is a step forward though it is only offered on their biggest engines? Multi air looks very flexible and should actually accomplish most of what I was looking for. Is any car maker using it? These are both "brute force mechanical" solutions but pretty effective. Keep in mind when considering the magnetic demands of an electronic valve train that the magnetics could be employed to move the valves in both directions with infinite control range of the available acceleration. The valves could move very quickly through most of the range of motion without slamming at either end. And only a very light helper spring would be needed as a fail safe and modern valves themselves are very light. Complete computer control of valve timing with Multi air or similar magnetic system along with direct injection will bring a quantum leap forward in broadening the sweet spot on the BSFC map in both aspects of rpm and load. Load almost becomes an obsolete term being replaced by percentage of maximum request in an engine with no throttle plate.

All BMWs use valvetronic at this point and the Fiat 500 and Dodge Dart 1.4 turbo use multiair. I'm sure it'll be on all chrysler products in the next couple of years. A magnetic system would only be able to turn ON or OFF. You would need a linear action motor or some way to mechanically limit the amount of lift to make it VVL which brings you back to some kind of cam control. I don't see the benefit over the existing systems. I know a few manufacturers are going from hydraulic cam timing control to electric for faster response and accuracy. Toyota calls it VVT-iE
http://en.wikipedia.org/wiki/VVT-i#VVT-iE

http://www.youtube.com/watch?v=eO55XgK5NcU