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
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:
stereoscopic image illustrates a part of the control shaft with the rollers
(red), the roller pins (blue), the rods (brown), and the actuators / lash
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
Pattakon VVA Rod_Roller version on a 1600cc 16v Citroen - Peugeot engine.
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