Holycrap what was that noise!!!???

[highboost951]

Taken from rennlist racing digest, WOW!

Subject: The Power of Centrifugal Force
From: paulamico@comcast.net
Date: Tue, 8 Apr 2003 22:29:22 -0400
X-Message-Number: 1

Had to share this with the list. My wife and I took our 968 to VIR last
weekend. We both drove with no problems for the first two days. In the
last session of the second day I was driving up the back straight, I
heard
a bang, followed by a louder one a couple of seconds later, and the
intense smell of coolant. I nursed it back to the pit and got it shut
down. Looked under the hood and found a mess. The cooling blades on
the
alternator had let go (only two were still left in place). The damage
was
pretty impressive.

- Two blades went straight up into the hood. They hit the center brace
on the hood, put two holes in the brace and two large dimples in the
hood.
It was clear if they hit the hood they would have gone right through
it.

- One piece went into the frame rail nearest the alternator. It bent
in
a half-dollar sized section of the rail by about a half inch, including
the corner, and punched a 3/4 inch hole in the rail.

- A two-blade piece went the other way. It sliced the upper radiator
hose completely in half like a knife, continued on to put a three inch
split in the timing belt cover and kept going to tear up the balance
shaft
belt and gouge the balance shaft pulley (lucky it wasn't the timing
belt).

- Ricochet damage included various cuts and scrapes on the alternator
belt and a chip on the Accusump.

I've never seen anything like it. Neither had anyone else we showed it
to. Any of you out there?

That centrifugal force is something else.

--Paul Amico

[Mark_944S2]

Actually it was centripetal, not centrifugal, force that did it.

Mark

[highboost951]

I think you missed the point.

[fty]

Wow..nasty the only thing that comes close is whern clutch explodes

[Scott R]

Mine blew a bearing two weeks ago and siezed, at the time I thought it was a huge issue, but in reading your post I now consider myself very fortunate.

[AaronM]

Originally posted by Mark_944S2
Actually it was centripetal, not centrifugal, force that did it.

Mark

I believe you mean that it was the sudden lack of cerntrpital force that caused it. Centripital force is the force which pulls an object towards the centerpoint of its orbit. (For example, the side bolsters on your seat provide centripital force to counter the inertia that you experience in high-speed cornering.)

Centrifugal force is actually a non-existant entity. What is called centrifugal force is actully simple inertia as an orbiting object is always attempting to move in a straight line unless it is acted upon by an outside force (in this case, the centripital force that imparts an acceleration which creates that characteristic constantly changing velocity vector of an orbiting object). Centripital force is the force that counteracts inertia to make something orbit around a centerpoint.

With that said, all that is left to say is wow, I'm glad that my alternator cooling fins never let loose.

AaronM

[SoCal Driver]

A good argument for the larger diameter alternator "racing" pulleys.

As to the physics of the rotating mass: Think what would happen if one of the proposed large mass flywheel inertia storage flywheels decided to come apart!!!

Ever seen what a dragster clutch/pressure plate looks like "after"?