Is there such a thing as "internal" vs "external" rotor venting?

[MoPar Man]

If someone says there is such a thing as internally vs externally vented
brake rotors (for cars) - what could they mean?

If you have a rotor formed by 2 plates, the plates separated by an air
gap formed by a structural web or matrix or separators, then what
additional aspect of their construction would lead to one being called
an internally-vented rotor while a second would be called externally
vented?

(supposedly for the LH-era 300m there was a difference between the PHP
vs non-PHP option package in terms of the front rotors being internally
vs externally vented, something that may or may not have any findable
authoritative source...)

[MummyChunk]

Brake rotors are discs that are
attached to the wheels of a car and are used to slow down or stop the
vehicle when the brake pads are pressed against them. Brake rotors can
be vented or solid, depending on the design and purpose of the car.
Vented rotors have air gaps between the two plates that allow air to
flow through and cool down the rotor, while solid rotors are more
compact and cheaper, but less effective at dissipating heat.

Vented rotors can be further classified into internally vented or
externally vented, depending on the direction of the air flow.
Internally vented rotors have curved vanes or fins that direct the air
from the center of the rotor to the outer edge, creating a centrifugal
force that increases the cooling effect. Externally vented rotors have
straight or angled vanes that direct the air from the outer edge to
the center of the rotor, creating a suction effect that also cools
down the rotor.

The difference between internally and externally vented rotors is
mainly related to the performance and efficiency of the braking
system. Internally vented rotors are more common and suitable for most
cars, as they provide better cooling and less noise than externally
vented rotors. Externally vented rotors are more rare and specialized,
and are usually found on high-performance or racing cars, as they
offer more consistent braking and less fade than internally vented
rotors.

The Chrysler 300M had different types of brake rotors depending on the
option package. The Performance Handling Package (PHP) included
externally vented rotors on the front wheels, while the non-PHP models
had internally vented rotors. The PHP rotors were larger and heavier,
and required a different caliper and bracket to fit. The PHP rotors
were also more expensive and harder to find than the non-PHP rotors.


This is a response to the post seen at:
http://www.jlaforums.com/viewtopic.php?p=394141807#394141807