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Can longer plug wires lead to LATE firing ??

Posted By: Kern Dog

Can longer plug wires lead to LATE firing ?? - 04/07/13 06:11 AM

Maybe a theoretical question since electricity travels so fast, but...
In big block engines, #2 and #4 are really close to the distributor. numbers 5 and 7 are the furthest away. At high rpm is is at all possible that they are receiving the spark later than #s 2 and 4?
Posted By: dOrk !

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 06:22 AM

F-berri ..... do you stay up at nite THINKING about Q's like this ??...
Posted By: 451Mopar

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 06:39 AM

I think the answer is yes, but the difference will be vary, vary small?
Posted By: dOrk !

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 06:45 AM

at 186,000 miles per second(or there abouts) ....vary VARY s m a l l !
Posted By: 70Duster440

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 06:46 AM

Noodle this: http://en.wikipedia.org/wiki/Speed_of_electricity
Posted By: 70AARcuda

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 06:50 AM

make sure you time your engine using the longest spark plug wire...and you will never have late timing.....
Posted By: 340SHORTY

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 09:55 AM

Posted By: 70Cuda383

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 12:52 PM

Quote:

make sure you time your engine using the longest spark plug wire...and you will never have late timing.....




but the what do you do about the shortest plug wires? they'll be premature.


I like to use all the same length spark plug wires because of this. works incredibly well on my 4.7, keeping all the sparks in time.
Posted By: jcc

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 01:59 PM

Quote:

Quote:

make sure you time your engine using the longest spark plug wire...and you will never have late timing.....




but the what do you do about the shortest plug wires? they'll be premature.


I like to use all the same length spark plug wires because of this. works incredibly well on my 4.7, keeping all the sparks in time.



I eqiuallze all my plug wires with no sharp turns.
Posted By: jcc

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 02:02 PM

Quote:

Quote:

make sure you time your engine using the longest spark plug wire...and you will never have late timing.....




but the what do you do about the shortest plug wires? they'll be premature.


I like to use all the same length spark plug wires because of this. works incredibly well on my 4.7, keeping all the sparks in time.



I eqiuallze all my plug wires and make sure no sharp turns.
Posted By: Dodgem

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 02:21 PM

you guys make me laugh since electricity travels 186,000 miles a second it travels 186 miles in 1000th of a second which is 982,080 feet per 1000th of a second say the longest to shortest plug wire is 2 feet longer that would take 1/491040 of 1/1000 of a second to travel that extra 2 feet.

now if you had a plug wire or two that reached around the world so one plug wire 2 feet long and one 24000 miles long (whats that something like 126,000,000 feet?? ) it would take .129 seconds longer to get to the cylinder.

Posted By: Dodgem

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 02:34 PM

If your worried about dirty wires slowing down the spark get a set of these
http://kalecoauto.com/index.php?main_page=product_info&cPath=9&products_id=27


and why bother degreeing a cam now that these are available
http://kalecoauto.com/index.php?main_page=product_info&cPath=9&products_id=27

and boost your power with one of these
http://kalecoauto.com/index.php?main_page=product_info&cPath=12&products_id=49

and when your done use the all new butt dyno to see what the improvements did
http://kalecoauto.com/index.php?main_page=product_info&cPath=6&products_id=8
Posted By: jcc

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 02:41 PM

Quote:

you guys make me llaugh







I thought that was whole point
Posted By: Dodgem

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 02:46 PM

Quote:

Quote:

you guys make me llaugh







I thought that was whole point



well it brightened up my morning for sure! :-)
Posted By: 62maxwgn

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 02:47 PM

And you really have to watch fuel line routing,liquid flows faster down than up ! I know,it's under pressure so it doesn't matter .
Posted By: Triggerfish

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 03:00 PM

Quote:

Quote:

Quote:

you guys make me llaugh







I thought that was whole point



well it brightened up my morning for sure! :-)




Simple solution...just use a smaller gap on the plugs with the longer wires...or, get the Accel shorties...
Posted By: 360view

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 03:03 PM

The question is not silly

all real world electrical circuits
have some

resistance
capacitance
inductance

if the ignition wires used
have appreciable
capacitance and/or inductance
then this will delay in time
the build up of
"flashover voltage"
at the spark gap

the delay is not due to a change in the speed of light
but because of the time to build up
stored energy in capacitive or inductive fields

typical carbon core factory ignition wires
will not have much capacitance or inductance
.. but can have enough capacitance to cause
"crossfire"
to a nearby wire from another cylinder's
if they run close and parallel

Chrysler has had problems with this:

http://dodgeram.info/tsb/1998/18-48-98.htm

spiral wound metal core
low RFI design ignition wires
will have more measured inductance
but the design is an inherently bad
"antenna"
for high frequency AC

aircraft gasoline engine ignition wires
can be fully covered by a shield
for RFI reasons
and might measurably slow down
the speed at which flashover voltage builds up
but this is understood and compensated for

as an extreme experiment
if you took an
extra long solid metal core ignition wire
and wrapped it numerous times
around an iron bar midway
before connecting it to the sparkplug
the delay would be as great as practical
and spark burn time would be extended somewhat
as the inductive fields discharged as the current declined
Posted By: 69hemibeep

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 03:04 PM

I like to use equal length wires and wrap the extra wire around empty toilet paper tubes which slip over a toilet plunger that I stick to the inner fender. That way you don't kink off the electricity
Posted By: Commando1

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 03:29 PM

Quote:

The question is not silly

all real world electrical circuits
have some

resistance
capacitance
inductance

if the ignition wires used
have appreciable
capacitance and/or inductance
then this will delay in time
the build up of
"flashover voltage"
at the spark gap

the delay is not due to a change in the speed of light
but because of the time to build up
stored energy in capacitive or inductive fields

typical carbon core factory ignition wires
will not have much capacitance or inductance
.. but can have enough capacitance to cause
"crossfire"
to a nearby wire from another cylinder's
if they run close and parallel

Chrysler has had problems with this:

http://dodgeram.info/tsb/1998/18-48-98.htm

spiral wound metal core
low RFI design ignition wires
will have more measured inductance
but the design is an inherently bad
"antenna"
for high frequency AC

aircraft gasoline engine ignition wires
can be fully covered by a shield
for RFI reasons
and might measurably slow down
the speed at which flashover voltage builds up
but this is understood and compensated for

as an extreme experiment
if you took an
extra long solid metal core ignition wire
and wrapped it numerous times
around an iron bar midway
before connecting it to the sparkplug
the delay would be as great as practical
and spark burn time would be extended somewhat
as the inductive fields discharged as the current declined



You weren't suppose to take him seriously...
Posted By: Supercuda

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 03:45 PM

Quote:

The question is not silly

all real world electrical circuits
have some

resistance
capacitance
inductance

if the ignition wires used
have appreciable
capacitance and/or inductance
then this will delay in time
the build up of
"flashover voltage"
at the spark gap

the delay is not due to a change in the speed of light
but because of the time to build up
stored energy in capacitive or inductive fields

typical carbon core factory ignition wires
will not have much capacitance or inductance
.. but can have enough capacitance to cause
"crossfire"
to a nearby wire from another cylinder's
if they run close and parallel

Chrysler has had problems with this:

http://dodgeram.info/tsb/1998/18-48-98.htm

spiral wound metal core
low RFI design ignition wires
will have more measured inductance
but the design is an inherently bad
"antenna"
for high frequency AC

aircraft gasoline engine ignition wires
can be fully covered by a shield
for RFI reasons
and might measurably slow down
the speed at which flashover voltage builds up
but this is understood and compensated for

as an extreme experiment
if you took an
extra long solid metal core ignition wire
and wrapped it numerous times
around an iron bar midway
before connecting it to the sparkplug
the delay would be as great as practical
and spark burn time would be extended somewhat
as the inductive fields discharged as the current declined



Thanks, Professor

Way to ruin a useless thread, lol.
Posted By: jcc

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 03:56 PM

Ne
Isnt there a treadmill in this thread somewhere?
Posted By: dezduster

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 04:15 PM

WOW so does this thread demystify the fact that my 440 punctured holes through preignition or detonation on #2 and 4 cylinders?
I had an MSD timing retard dial setup and unwiesly timed the engine with the adjustment in near center of its throw.
Long story short,in the heat of battle on a dark desert highway blueberries and cherries flashing in the rear view it got bumped up to a total of 55ish degrees. In less than 2 miles of uphill grade she popped holes in the 2 forementioned pistons, yes they were hyperutectics. ALSO shortest plugwires. Or was it lean? But on just those two cylinders?
No I was not caught red handed she still ran on six and since the Charger I was in was a Ram Charger I used alternative routes to elude those who opresse us who enjoy the finer things in life such as POOOWER unleashed.
What was cheaper a ticket or a rebuild I dont know what the ticket would have been, but the insurance hit from an SR22 on a teen is huge. So I think a two grand rebuild was a fair ticket. LESSONS LEARNED, MANY INFACT.
Posted By: Pacnorthcuda

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 04:51 PM

Back when I was young and it was 5 inches it often fired prematurely. Like a gun with a hair trigger it was quick. As I grew, and it grew in length, the time to fire was delayed significantly.
That's not a bad thing, you just need to adjust for it and time the events appropriately.
Posted By: GTX MATT

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 05:01 PM

Be sure that you run EQUAL LENGTH plug wires, especially when running equal length headers and indexing your spark plugs.
Posted By: notforsale440

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 05:08 PM

someone needs to invent "wireless" ignition
Posted By: jcc

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 05:10 PM

Diesel?
Posted By: Pacnorthcuda

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 05:23 PM

Quote:

Diesel?



Glow plug...
Posted By: dezduster

Re: Can longer plug wires lead to LATE firing ?? - 04/07/13 08:42 PM

You mean like coil on plug like modern Hemis and most every engine made?
Posted By: dogdays

Re: Can longer plug wires lead to LATE firing ?? - 04/08/13 05:20 PM

RE: 360view
Thanks for reminding/teaching me something new. I appreciated the lecture even if some others didn't. Brought me back to EE312.

R.
Posted By: feets

Re: Can longer plug wires lead to LATE firing ?? - 04/08/13 06:34 PM

Quote:

Quote:

Diesel?



Glow plug...



No glow plugs on Cummins.
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