Re: misconceptions on drilled rotors and SS lines

[Richard Welty <rwelty@domain.elided>]

At 11:13 AM 3/17/99 -0500, JJK1204@domain.elided wrote:
>>Are you sure? I was always told that it was not for cooling, but to allow
the
>hot gas, which forms on heavy braking, to escape from between the pad and
>rotor. 

correct. cross drilled rotors, however, are only one of several approaches to
this issue, and there are others that work better:

slotted rotors
    the slots, cut across the face, tangentially to the inner radius of the
swept
    area, also relieve the pressure, with substantially less risk of weakening
    a vented rotor. there is a picture of a set of slotted rotors on a
Penske car
    on one of Carroll Smith's book covers, as i recall.

slotted pads
    this is why you will find brake pads with a vertical slot in the face
of the
    friction material.

the downsides of cross drilled rotors, some of which have already been
mentioned:

1) risk of weakening vented rotors due to holes drilled at inappropriate spots

2) reduction of size of rotor, reducing its utility as a heat sink

richard

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