Both for what concerns the area dedicated to the INTAKE , both for
the one dedicated to the EXHAUST, there are four sub-areas, one
dedicated to the definition of the LIFT, one for the KINEMATICS of
the valve train system, one for the DYNAMICS of the system, and one
that summarizes all the results both graphics and numerical, of the
work done.
The most important stage of the design is the definition of lift
law of the valve that you want obtain, so the software PROFESSIONAL
CAM PRO has studied in the detail this aspect. For first, the
software allows you to enter the main data of the lift that you want
achieve with the cam, so the valve timing, the maximum lift, and the
characteristics of the ramps for the recovery of the lash.
In addition to this you can choose the type of lift law that you
want to use. The software provides three main types:
NT-Polydyne
This type of lift law is based on particular "polydyne"
polynomials appropriately modified with a special algorithm
to optimally connect it to eventual ramps, hence the name
"NT-Polydyne".
NT-Spline
This type of lift law is based on "splines"
appropriately designed to create laws that satisfy the needs
of engine valve train systems and which connect in an
optimal manner to eventual ramps, hence the name
"NT-Spline".
NT-Trigonometric
This type of lift law is based on trigonometric laws
appropriately studied to create laws that satisfy the needs
of engine valve train systems, and modified with a special
algorithm to optimally connect to eventual ramps, hence the
name "NT-Trigonometric ”.
NT-Polynomial 8°
This type of lift law is based on an 8° polynomial law
appropriately modified with a special algorithm to optimally
connect to any ramps, hence the name "NT-Polynomial 8°".
NT-Dudley
This type of lift law is based on the particular
"polydyne" polynomials developed by Dudley appropriately
modified with a special algorithm to optimally connect to
eventual ramps, hence the name "NT-Dudley".
For each of these laws it is possible to manage some parameters that
modify the level of aggressiveness of the law
These bars are used to modify the characteristics of the
NT-Polydyne, the "expini" bar defines the initial exponent
of the polydyne, while the "deltaexp" bar defines the
spacing between the exponents. By clicking on the arrows you
scroll the cursors and by moving them from left to right you
will obtain increasingly aggressive lift laws.
These bars are used to modify the characteristics of the
NT-Spline, the "dur+" bar defines the duration of the
positive acceleration, while the "dur-" bar the duration of
the constant section of the negative acceleration. By
clicking on the arrows you scroll the cursors and by moving
them from left to right you will obtain increasingly
aggressive lift laws.
These bars are used to modify the characteristics of the
NT-Spline, the "dur+rise" bar defines the duration of the
positive acceleration in the valve opening phase, the
"dur-rise" bar the duration of the constant portion of the
negative acceleration in the phase of valve opening, while
the "dur+down" bar defines the duration of the positive
acceleration in the valve closing phase, and the "dur-down"
bar the duration of the constant section of the negative
acceleration in the valve closing phase. By clicking on the
arrows scroll the sliders and move them from left to right
you will obtain increasingly aggressive lift laws.
This bar is used to modify the characteristic of the
NT-Trigonometric, the “ratio_acc” bar defines the ratio
between the positive acceleration and the negative
acceleration. By clicking on the arrows you scroll the
cursor and by moving it from left to right you will obtain
increasingly aggressive lift laws.
This bar is used to modify the characteristics of
the NT-Dudley, the “expini” bar defines the initial exponent
of the polydyne. By clicking on the arrows you scroll the
cursor and by moving it from left to right you will obtain
increasingly aggressive lift laws.
Furthermore these laws can also have ramps to recover the valves
clearance, and can also have an asymmetric profile.
