[s-cars] RE: Ceramic Ball Bearings for Turbo's

[CyberPoet]

Cody Asked:
Also any one think it is worth doing Ceramic Ball Bearings?

Marc Responds:
The primary benefits of ceramic bearings in any application are:
(A) Lack of heat conductance (reduces heat transference from one side
to the other);
(B) Permeability of oil (ceramics can absorb oil to a degree, so even
if starved for oil at some point, they will self-lube for a little
while, which may be enough of a difference to survive a race);
(C) Long term storage (will not rust irrelevant of the environment);
(D) Non-melting. In turbine applications especially, bearings can
become hot enough between heat exposure and friction over time to slag.
Won't happen with ceramic.
(E) Some ability to deal with coking (the creation of ash in the
bearing runs from oil being burnt to ash) by virtue of the ability to
absorb the ash into the pores of the ceramic (only in a limited degree
-- again, perhaps just enough to get through the end of a race).

Yet, by comparison, metal-alloy bearings are still a better choice for
normal day-to-day driving, provided they are engineered for the task.
Metal-alloys are harder normally than ceramics and are inherently more
vibration-resistant (vibrations that normally occur as you drive over
the types of rough surfaces of city streets, etc, compared to track
surfaces).

Strange and useless fact: In WW2, the Rolls Royce plants cranking out
aircraft engines used bearings made of special heavy African & South
American hardwoods, because the wood was inherently oil-bearing wood --
if the oil supply to the bearings were starved, the wooden bearings
would self-lubricate using the oil the wood inherently had in it, and
thus (at least in theory) permit the bearings to work a little longer,
possibly long enough to get the aircrew home. They continued the
tradition in their car engines for quite a number of years afterwards.

Cheers
=-= Marc Glasgow
Prepress and graphics Macintosh consultant Pinellas Hillsborough Florida
www.cyberpoet.net