not at all...thanx for the information...
richard
----- Original Message -----
From: "Terry Thompson" <epharisto@yahoo.com>
To: <spitfires@autox.team.net>
Sent: Tuesday, January 16, 2001 10:23 AM
Subject: Re: 79 spit starter meltdown..?
>
> Gauge wire works backwards from screw sizes (#4 screws
> are tiny...#12's are large). In wiring, the largest
> gauges are zero (0) or what is referred to as a Aught
> gauge. The smallest wires (phone cords) use 24 gauge.
> No one really knows why they do it like that.
>
> In gauges of wire, the wires in your harness for
> lights and things are around 12-14 gauge (10 amp max)
> . House-hold wiring is around the 8-19 gauge area (AC
> wiring uses more amps for the same or similar voltage
> requirement than DC). Your starter sucks high amperage
> at a low voltage. And you need ATLEAST a 4 gauge wire.
> Most automobiles use 2 gauge starter wires.
>
> Just as an introduction to electrical engineering:
>
> AMPERAGE refers to the VOLUME or the amount of the
> electrons passing through a conductive surface.
> VOLTAGE refers to the SPEED at which the electrons are
> moving. Wattage is a formula to calculate the total
> usage of electricity on a circuit. It's value is
> Amperage times the voltage. A 100 watt bulb which runs
> on your 120 volt home current uses 1.2 amps (100 / 120
> = 1.2).
>
> Diameter of the wire (gauge) doesn't affect Voltage
> because voltage is not an amount, it's a speed or
> rate. But, you do need to consider Diamater when
> figuring out Amperage.
>
> Electrical current can be thought of as water moving
> through a pipe. So, like in a water pipe - the larger
> the pipe, the greater volume of water that can pass
> through it, right? So if you try to put more water in
> the pipe than it can contain it will burst.
> The physics of it are diffent. In electrical terms,
> the RESISTANCE is increased, and a tug of war ensues
> because the motor is trying to PULL more current than
> can fit through the conductor. But the end result is
> the same, broken conduit somewhere in the circuit.
> This can also cause the motor to loose out on the tug
> of war and brake down.
>
> A Lucas starter motor can pull as much as 375 amps for
> lock rotation. That's the upper limit of a 6 gauge
> wire on DC current. And a sustained burst will test
> your wiring quickly. So you might be better off going
> with a 4 gauge or 2 gauge just to be super duper safe.
>
> There are also considerations for distance, because as
> you increase distance, you lose amps (like a leaky
> water pipe), but the motor still requires the rated
> amperage to turn a rotation, so you need to put even
> MORE amperage through the line to compensate for the
> "leak". (I know all the electrical engineering folks
> on the list are going to jump on my case for making
> analogies to water).
>
> As a general rule the following constitutes safe upper
> limits of Amperage draw for conductive circuits. AWG =
> Gauge. All are listed at 6 feet of distance.
>
> 18 awg = 25 amp max (ampacity)
> 16 awg = 37 amp
> 14 awg = 60 amp
> 12 awg = 95 amp
> 10 awg = 151 amp
> 8 awg = 241 amp
> 6 awg = 390 amp
> 4 awg = 616 amp
> 2 awg = 1000 amp
>
> ALSO. Don't forget that the terminations (the eyelets
> and posts) must be clean and also rated for high
> amperage current. Resistance anywhere in that circuit
> spells trouble for your starter.
>
> Sorry if that's been confusing, or if you just didn't
> give a crap. You're probably even more confused now.
>
> -Terry
> '76 spit 1500
>
> --- richard bonilla <richard@bonilla.com> wrote:
> >
> > hummm...i will take another look at the
> > connections...and upgrade
> > my cable to at least a 6 gauge...any reason not to
> > jump to the
> > next bigger gauge...say 8?...
> >
> > richard / colorado
> >
> >
> >
> >
> > ----- Original Message -----
> > From: "Vic Whitmore" <vicwhit@home.com>
> > To: "Nolan Penney" <npenney@mde.state.md.us>
> > Cc: <spitfires@autox.team.net>;
> > <richard@bonilla.com>
> > Sent: Tuesday, January 16, 2001 9:14 AM
> > Subject: Re: 79 spit starter meltdown..?
> >
> >
> > > I have my doubts that the there is a real problem
> > here with Spitfire
> > starters in
> > > general.
> > >
> > > Could it be that a loose or partially corroded
> > terminal (internal or
> > external)
> > > resulted in an ohmic contact?. With the very high
> > current load of starting
> > > passing through this small resistance, significant
> > heat will build up.
> > > Components that would not normally melt with clean
> > connections may melt
> > even
> > > after a short 15 to 30 second cranking. Hence as
> > "good" starter can be
> > abused at
> > > times without any damage but a "poor" starter with
> > ohmic connections will
> > > self-destruct earlier than expected.
> > >
> > > Vic Whitmore
> > > 76 Spitfire
> > > Thornhill, Ontario
> > >
> > > Nolan Penney wrote:
> > > >
> > > > 10 seconds on, but how long off? It should be
> > 15-30 minutes to allow
> > > > a good cooling down. Now of course, none of us
> > actually do that.
> > > > We crank and crank and crank, hoping that the
> > motor will act enough
> > > > like a heat sink to allow us to get away with
> > it. Often times you can,
> > > > sometimes you cannot. Most starter motors will
> > allow you to
> > > > get away with upwards of a solid minute of
> > cranking before
> > > > self destructing in a terminal manner. But this
> > does not mean
> > > > that all starter motors will do this.
> > > >
> > > > I will say that my Spitfire has tolerated
> > upwards of 30 seconds
> > > > solid cranking time, with burst after that
> > giving nearly a minute
> > > > of cranking time. Nothing has melted down in
> > the process,
> > > > but I do understand I'm breaking down insulation
> > in the process
> > > > and cutting my motors life short doing this.
> > > >
> > > > To actually melt the plastic housing the hot
> > post sits in, I'd
> > > > speculate that you were cranking...shall we say
> > enthusiastically
> > > > and excessively? :-)
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