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VVA "Rod Roller" version


Intellectual Property: patent EP 1,697,619



The "Rod Roller" version of Pattakon VVA on the intake valves of a Citroen/Peugeot 1600 cc,16 valve





This design is "universal" (most cylinder heads "compatible").

The control shaft is directly connected to the gas pedal by the gas cable. The deeper the gas pedal is pressed, the more the control shaft rotates increasing the valve stroke. When the gas pedal is released the normal intake valve springs restore the control shaft to its �idling� position.
Depending on the control shaft angular position the valve lift profile varies continuously from zero (for valve deactivation if desirable), to tiny (for idling), to mild, to medium, to racing (top curve), all in the same engine, all instantly available:



The following stereoscopic image illustrates a part of the control shaft with the rollers (red), the roller pins (blue), the rods (brown), and the actuators / lash adjusters:





The quick moving parts are "true" lightweight.
Even with the toughest valve springs, the engine at normal conditions (i.e. low to medium revs) "feels" (as regards friction, wear etc) softer valve springs than conventional.
The intake valves make the "throttling" (ideal for efficient and cheap ITB).
The lash adjusters - if desirable - can be hydraulic




A RodRoller VVA mechanism shown at four (of the infinite available) modes of operation.
Click on the image to download the animation (0.4 MB) and open it.
Press SpaceBar to see each mode seperately.
Move mouse above the animation window to align rhythm.
Double click the animation (or press ESC) to Quit.

Below is a stereoscopic animation (0.9 MB) of the parts of the above mechanism.




With a different control shaft the above "Constant Duration VVA" changes to a "Lost Motion VVA" as shown below (the axis of rotation of the control shaft goes from the "top center" to the "bottom center" of the rods) .
BMW's "Valvetronic" is a "Lost motion VVA": decreasing the valve stroke, the valve duration - in crankshaft degrees - is also decreased.
Compare BMW's Valvetronic to Pattakon's Rod Roller Lost Motion VVA in functionality, simplicity, accuracy (number of "joints" interposed), height, lightweight, inertia loads, cost and capability for high revs (specific output).




Pattakon VVA Rod_Roller version on a 1600cc 16v Citroen - Peugeot engine.

Mouse hover above an image: content
Mouse click an image to download the relevant photo, video, animation.



For more:

Click here for the "pattakon VVAs" (6.5MB Power Point presentation, the last presentation at EngineExpo2008 Technology Forum, Stuttgart Germany)

or

Click here for the "pattakon VVAs" presentation in PDF format (7.5 MB)



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