Coil Wire Question
dumbjaw
make sure which is the positive side of the coil. I have the coil mounted
on the side of the engine so would it be the front or rear post? Thanks in
advance.
Dave
Hemipower
>Date: 04/18/2001 5:28 PM EST
>Message-id: <ux8hvZFyAHA.301@cpmsnbbsa09>
Look closely as it may/should be
marked on the coil. Look for a
little raised + or -.
--
Hemipower
55 FLH "Failure Is Only The Opportunity To More
Bored n Stroked Intelligently begin again" Henry Ford
DTSS,BS110
HogDoctor
If you're running a single coil with two plugs (dual fire) like the stock
single cam motor setup,
then it doesn't matter, you can run the power through the coil either way.
--
HogDr SENS BS#123
---------------------------------------------------------------
HD Dealer Technician at your service......
My Employer's site: http://www.wishd.com
My site: http://www.execpc.com/~patrickz/patricksite.htm
---------------------------------------------------------------
Hemipower
>Date: 04/18/2001 10:00 PM EST
>Message-id: <3ade5486$0$18893$272e...@news.execpc.com>
>
>dumbjaw wrote:
>
>> Just want to double check, but I am putting a big twin together and want to
>> make sure which is the positive side of the coil. I have the coil mounted
>> on the side of the engine so would it be the front or rear post? Thanks in
>> advance.
>>
>> Dave
>
>If you're running a single coil with two plugs (dual fire) like the stock
>single cam motor setup,
>then it doesn't matter, you can run the power through the coil either way.
>
With all due respect Doc,
any coil will work with the primary
leads reversed. It will just
perform about 20% less then its
designed capacity.
Studies have shown that a spark
will jump the plug gap
a lot easier if the center electrode
is of negative polarity.
It is for this reason that coil manufactures
design their coils so the high tension
lead is negative polarity.
That is why most coils are marked + and - respectively.
There are coils that are produced without the proper designations and this can
confuse some people.
There is a way to check for correct
polarity.
With the motor running, take a pair of insulated pliers and remove one
of the spark plug wires. Hold the
wire about a 1/4 away from the plug end. Then insert the sharpened point of a
pencil into this 1/4 inch gap.
It should produce an orange
sparkly flair flowing toward the plug.
If so, your polarity is correct
If OTOH the sparks go toward
the cable end, then reverse
you coil connections.
So unless any of the laws of physics,electro/magnatism,
or coil manufacture
have changed, I have yet to
receive the memo. : )
Let me get this round.
Preacher
> >HogDoctor hog.d...@execpc.com
>
> >dumbjaw wrote:
> >> Just want to double check, but I am putting a big twin together and
want to
> >> make sure which is the positive side of the coil. I have the coil
mounted
> >> on the side of the engine so would it be the front or rear post?
Thanks in
> >> advance.
> >
> >
> >If you're running a single coil with two plugs (dual fire) like the stock
> >single cam motor setup,
> >then it doesn't matter, you can run the power through the coil either
way.
> >
>
> With all due respect Doc,
> any coil will work with the primary
> leads reversed.
<snip>
> So unless any of the laws of physics,electro/magnatism,
> or coil manufacture
> have changed, I have yet to
> receive the memo. : )
Then you have yet to receive the memo. The "laws" have changed. It's called
"Waste Spark Ignition" and like Patrick Z. says, you can connect the primary
wires either way. THIS IS NOT A CONVENTIONAL COIL. One plug fires
positively, the other fires negatively. So one plug is actually using more
required voltage. Put the bike on a scope and you'll see one firing line
about 30% higher then the other. Your figure of 20% is the low end of the
range. It takes between 20%-40% more required voltage to fire a spark plug
with primary leads reversed, on A CONVENTIONAL COIL.
You're talking about Apples. Hog Doc is talking about Oranges (single fire
vs. dual fire).
I have no idea if the original poster is running Apples or Oranges for his
ignition.
Preacher
Scott Drysdale
not knowing much about physics, i'll go along with the "center
electrode likes to be negative" thing.
HOWEVER: here's what the harley ignitions i've played with look like.
use a fixed width font to view this without migraines.
+12V
o
| \---o front o---+
| / plug |
+---\ || \ ---
/ || / -
primary \ || \ secondary
/ || /
+---\ || \
| /
| \---o rear o----+
o plug |
breaker ---
o -
|
---
-
the breaker might be a fancy pants electronic ignition or a set of
points and a condenser, but isn't important for our purposes.
the funny vertical thing is the coil (a transformer). the wires from
the coil secondary go to the center electrode of the plugs. the
curved plug electrodes are connected together via the engine ground
(where they bolt into the heads).
notice that the current path in the secondary goes through both plugs,
which are in series (in different directions) across the secondary.
if you follow your reasoning, only one plug has "proper" polarity. if
you flip the connections at the primary, you'll flip which plug is
"proper".
maybe if you've got a seperate coil for each plug (non-wasted-spark
setup) or a true distributor-type system you can do what you suggest,
but on a "normal" harley you can't.
i guess on a two-plugs-per-head machine, you could have one coil one
way and the second coil the other way and have a compromise :)
--
// scott drysdale // drys...@brandywine.net
// amigas and panheads and guns, oh my!
Hemipower
handy, but if I recall when the spike is causing an inverted WF below the Z
line then the leads are reversed. In theory then I should see a 100%
difference. With
one firing at 5-10KV and the other
-5-10KV. : )
Your figure of 20% is the low end of the
>range. It takes between 20%-40% more required voltage to fire a spark plug
>with primary leads reversed, on A CONVENTIONAL COIL.
I didn't say 20% more required
voltage to fire, but that the coil will
perform about 20% less then its
designed capacity.
>
>You're talking about Apples. Hog Doc is talking about Oranges (single fire
>vs. dual fire).
>
>I have no idea if the original poster is running Apples or Oranges for his
>ignition.
>
>
Well, my orang,,ahh dual fire
coil has two towers and they
are clearly marked + and -.
Do they intend for a particular
cylinder to fire better?
I can't see why there would be that
much difference in spark value
between cylinders.
Don't take this as an argument,
I just need to delve into it a
little deeper.
Waro
Hemipower wrote:
<snip>
>
> Do they intend for a particular
> cylinder to fire better?
> I can't see why there would be that
> much difference in spark value
> between cylinders.
>
There isn't......it's like lighting a cigarette with a bick or blow
torch.....still gets lit. 20% isn't that much concidering 30K to 40K volts.
Remember it takes approx. 30K volts for a spark to jump an inch if my memory
serves me well.....getting old ya know.
Hemipower
>Date: 04/19/2001 7:07 PM EST
>Message-id: <3ADF7DC9...@charter.net>
>
>
>
>Hemipower wrote:
>
><snip>
>
>>
>> Do they intend for a particular
>> cylinder to fire better?
>> I can't see why there would be that
>> much difference in spark value
>> between cylinders.
>>
>
>There isn't......it's like lighting a cigarette with a bick or blow
>torch.....still gets lit. 20% isn't that much concidering 30K to 40K volts.
You have to remember I'm
running a 6v set up. It only
produces 15-18,000 volts.
I'm just trying to figure out
the phantom rear cylinder
fouling on some bikes.
From my auto days I can remember 20% deficiency
as enough to cause a car
not to start in the winter.
20% loss in efficiency may
not have an apparent effect
under normal condition, but it
will certainly be felt if conditions
demand max coil efficiency.
I hate to beat this in the ground
but I can't stand not having
anything I own not running at 100%.
Even if my 100% is only half of what
you put out. : )
Hemipower
>Date: 04/19/2001 2:05 PM EST
>Message-id: <3adf2ff5....@news.brandywine.net>
I guess I will need to cut an old
coil apart and see how it is wired
internally.
Thanks for your input Scott.
Joe Mama
>>> Just want to double check, but I am putting a big twin together and want to
>>> make sure which is the positive side of the coil. I have the coil mounted
>>> on the side of the engine so would it be the front or rear post? Thanks in
>>> advance.
>> If you're running a single coil with two plugs (dual fire) like the stock
>> single cam motor setup,
>> then it doesn't matter, you can run the power through the coil either way.
> With all due respect Doc, any coil will work with the primary leads reversed.
> It will just perform about 20% less then its designed capacity. Studies have
> shown that a spark will jump the plug gap a lot easier if the center electrode
> is of negative polarity. It is for this reason that coil manufactures design their
> coils so the high tension lead is negative polarity. That is why most coils are
> marked + and - respectively.
I don't know anything about this, but for some reason HD never did mark their
coils positive/negative, however, the old vertical steel housed 6V coils were
left side/front terminal positive and right side/rear terminal negative..
> There are coils that are produced without the proper designations
> and this can confuse some people. There is a way to check for
> correct polarity. With the motor running, take a pair of insulated
> pliers and remove one of the spark plug wires. Hold the wire about
> a 1/4 away from the plug end. Then insert the sharpened point of a
> pencil into this 1/4 inch gap. It should produce an orange sparkly
> flair flowing toward the plug. If so, your polarity is correct If OTOH
> the sparks go toward the cable end, then reverse you coil connections.
> So unless any of the laws of physics,electro/magnatism, or coil
> manufacture have changed, I have yet to receive the memo. : )
Well, I use a TESLA coil, which throws white lightning bolts out of the
exhaust pipes at approaching vehicles and causes my body to glow
with a brilliant blue aura, but man it *never* misfires..
> Let me get this round.
Nah, I think i've had enough..
-jm
To return mail no spam, change the reply address of:
"joe mama at rare bird dot com"
to
"joe mama at rare bird dot net"
Hemipower
>Date: 04/20/2001 1:22 AM EST
>Message-id: <3adfd15b...@news.pon.net>
The after market 6volt coils I have are both clearly marked.
>
>> There are coils that are produced without the proper designations
>> and this can confuse some people. There is a way to check for
>> correct polarity. With the motor running, take a pair of insulated
>> pliers and remove one of the spark plug wires. Hold the wire about
>> a 1/4 away from the plug end. Then insert the sharpened point of a
>> pencil into this 1/4 inch gap. It should produce an orange sparkly
>> flair flowing toward the plug. If so, your polarity is correct If OTOH
>> the sparks go toward the cable end, then reverse you coil connections.
>
>> So unless any of the laws of physics,electro/magnatism, or coil
>> manufacture have changed, I have yet to receive the memo. : )
>
>Well, I use a TESLA coil, which throws white lightning bolts out of the
>exhaust pipes at approaching vehicles and causes my body to glow
>with a brilliant blue aura, but man it *never* misfires..
Ohhh, I like it!
>> Let me get this round.
>
>Nah, I think i've had enough..
>
then prune juice it is.
Preacher
> not knowing much about physics, i'll go along with the "center
> electrode likes to be negative" thing.
That is true. So far no argument with HP.
> HOWEVER: here's what the harley ignitions i've played with look like.
> use a fixed width font to view this without migraines.
+12V
o
| \---o front o---+
| / plug |
+--- / || \ ---
\ || / -
primary / || \ secondary
\ || /
+--- / || \
| /
| \-o rear o--+
o plug |
breaker ---
o -
|
---
-
*This* is correct.
> the breaker might be a fancy pants electronic ignition or a set of
> points and a condenser, but isn't important for our purposes.
Correct again. It doesn't matter *how* you control the ground side of the
primary circuit, as long as you control it. A set of breaker points, a
transistor, whatever.....as long as you are able to turn it on and off.
> the funny vertical thing is the coil (a transformer). the wires from
> the coil secondary go to the center electrode of the plugs. the
> curved plug electrodes are connected together via the engine ground
> (where they bolt into the heads).
>
> notice that the current path in the secondary goes through both plugs,
> which are in series (in different directions) across the secondary.
> if you follow your reasoning, only one plug has "proper" polarity. if
> you flip the connections at the primary, you'll flip which plug is
> "proper".
That is *exactly* right. The only thing that will happen if you connect the
primary wires in reverse is the the opposite plugs will change polatiry.
I'll go look at the ignition system on my '55 FLH (just like Hemipower says
he has) and see (A) how many sets of points are in the distributor (which
will tell me if it's single or dual fire) and (B) if my OEM coil is marked
"+ and -".
If it's a waste spark ignition it may be marked, but it won't matter how
it's connected.
Preacher
Hemipower
>Date: 04/20/2001 1:10 PM EST
>Message-id: <9bpu6r$v9p$1...@slb0.atl.mindspring.net>
You have to remember, mine is
no where near stock.
I have a single set of points
with an automatic advance dist.
Nothing like it came from the
factory.
and see (A) how many sets of points are in the distributor (which
>will tell me if it's single or dual fire) and (B) if my OEM coil is marked
>"+ and -".
>
>If it's a waste spark ignition it may be marked, but it won't matter how
>it's connected.
>
>
I'll take your guys word for it.
Joe Mama
>> I don't know anything about this, but for some reason HD never did mark their
>> coils positive/negative, however, the old vertical steel housed 6V coils were
>> left side/front terminal positive and right side/rear terminal negative..
> The after market 6volt coils I have are both clearly marked.
A good marketing feature, but none of the original HD 6/12v
standard contact point ignition coils were..
>> Well, I use a TESLA coil, which throws white lightning bolts out of the
>> exhaust pipes at approaching vehicles and causes my body to glow
>> with a brilliant blue aura, but man it *never* misfires..
> Ohhh, I like it!
That's what my wife tells me..
>>> Let me get this round.
>> Nah, I think i've had enough..
> then prune juice it is.
Yeah, i'm so full of crap that I need a good cleanout..
Scott Drysdale
Allen Shieh
As an experienced cable manuf and custom Coil cable specialist, we have been help customers custom coil cable from different field, such as consumer electronics, office supplies, and specific fields…
In this passage，we would like share with you what we have experienced and what customer cares during the cooperation and the custom manufacturing of these coiled extension cable.
Custom Coiled Cable Length
People use a coiled cable mainly because of flex length, space saving and easy storage. Length resilience and extensibility of a curly cable is its attractive highlight, also a key factor we need to consider when we want to custom a coiled cable, so we put this point at the beginning.