<VV> Arcing wires in the dark (Now arcing damper.)

[Roger Gault]

I'd speculate that this rather tiny current is grounded through the throwout
bearing is a std trans car - lower resistance than the main bearings.
FWIW, in my previous life as an ion implanter designer, while chasing a
mysterious bearing/grease failure problem, I ran a series of experiments
running low currents ( about a milliamp) through some grease filled ball
bearings.  The resistance was almost unmeasureably low, leading me to
believe that the energy in any sparking was too low to vaporize the metal
surface.  As it turned out, the spalling failures I was seeing were caused
by the high vacuum rated silicone grease I was using - terrible film
strength at low speeds (300 rpm in my case).  The problem only occured when
under vacuum and I was testing at atmospheric pressure so I could see what
was going on.  Of course, nothing was going on at atmospere.  I didn't know
if my boss was going to kill me before or after I went insane.  I finally
tracked down the designer of the grease (who had quit the grease supplier
over their selling of the grease without a warning about the low speed
problem) and he explained the problem to me.  Changed grease, all was well.
They didn't even fire me. ;-)

Roger

----- Original Message ----- 
From: <RoboMan91324 at aol.com>
To: <virtualvairs at corvair.org>; <FrankCB at aol.com>
Sent: Tuesday, August 05, 2008 11:14 PM
Subject: <VV> Arcing wires in the dark (Now arcing damper.)


>
> Frank,
>
> If the aluminized paint dries brittle or becomes brittle with  age, it is
> likely to crack across the gap where the inner and outer sections of  the
damper
> move independently.  The arcing will start across the cracks in  the paint
> until the paint is eaten away and the same issue  remains.
>
> Here is a poser for the gang ..... If the static electricity  in the outer
> ring of the damper travels to the inner ring and then goes to  ground
through
> the crankshaft to the block, is it arcing from the crankshaft to  the
bearings
> and causing long term damage?  I know that this sort of thing  is a
failure
> mode in roller bearings.  Perhaps the engine oil is conductive  enough to
pass
> the electrical charge through without arcing.  Perhaps the  large surface
area
> between all of the bearings and the crank (plus the area of  the camshaft
in
> proximity to the block) is sufficient to last the normal life of  the
engine
> despite arcing.
>
> Inquiring minds want to know.
>
> Doc
>
> 60' Corvette, 61' Rampside, 62' Rampside, 64' Spyder coupe,  65'
Greenbriar,
> 66' Canadian Corsa Turbo Coupe, 67' Nova Super Sport, 68' Camaro  Ragtop
>
> ~~~~~~~~~~~~~~~
> In a message dated 8/5/2008 6:05:28 P.M. Pacific Daylight Time,
> virtualvairs-request at corvair.org writes:
>
> Message:  9
> Date: Tue, 5 Aug 2008 19:53:31 EDT
> From: FrankCB at aol.com
> Subject:  Re: <VV> Arcing wires in the dark
> To: dmonasterio at megared.net.mx,  chartzel at comcast.net,
> virtualvairs at corvair.org
> Message-ID:  <bfb.418110d9.35ca41fb at aol.com>
> Content-Type: text/plain;  charset="US-ASCII"
>
> Daniel,
> Why not just run a few  stripes of  conductive paint (aluminum paint?)
across
> the rubber  separator so that it  touches both the inner core and outer
metal
>  parts?
> Frank "likes easy to implement answers"   Burkhard
>
>
> In a message dated 8/5/2008 7:15:25 P.M. Eastern Daylight  Time,
> _dmonasterio at megared.net.mx_ (mailto:dmonasterio at megared.net.mx)   writes:
>
> Never  before thought on this fact which must happen on  dry weather only.
> The outer  part of the harmonic damper is isolated from  the engine body
by the
> bonding  rubber and rubbing against the belt all  the time, acumulating
static
>  electricity. If the outer portion of the  dampener becomes close enough
(we
> know it happens) to the timing housing  the sparking will occur. Worst
> scenario: Dry weather + outer edge of  dampener  too close to engine +
fuel pump
> leak... ????
>
> Daniel  Monasterio
> PS.  Will solder a small copper wire between both parts of  dampener in
all
> my vairs... just in  case.
>
>
>
>
> **************Looking for a car that's sporty, fun and fits in your
budget?
> Read reviews on AOL Autos.
>
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017 )
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