Spark energy

big2bird

big2bird

Charter Member, Founder Bird-Run, Cruise-In Bird-R
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Okay, so at what point is more spark "zero return?"
At some point, more is overkill, less reliable, and just detunes faster.:shocking:
 
Wow, Bird, what prompted this. You looking for a thesis topic? :D
Just thinking out loud..... What ever it takes to reliably ignite the air/fuel charge under all the extremes of changing operating conditions i.e.;
engine temperature
A/F charge temperature
A/F ratio
rpm
MAP.. (engine load)
humidity
spark timing
VE
etc.
etc.
not to mention the fact that some of these parameters can, and do, rapidly change.

I vote for overkill. :smash: No real penalty that I can see off hand. :fishing: What deteriorates that causes faster detune? These days the only thing that comes to mind is the spark plug electrodes and they are pretty tough. (Don't forget I dumped mechanical points along time ago) :harhar: I probably wind up changing mine long before the electrodes deteriorate.

Your turn..:bump:

Bullshark
 
big2bird said:
Okay, so at what point is more spark "zero return?"
At some point, more is overkill, less reliable, and just detunes faster.:shocking:
Click to expand...

These are max volts--under heavy loads.
25,000 volts is consided pretty much stock norm.
40,000 to 45,000 volts is considered Hiperf.
So anything over 50,000 is considered overkill -- if there is such a thing.

This comes from my talks with Accel.:phone:


These are just general--and are max volts. Under light load it will be a much lower rating.:quote:

Do you want to talk mulit-spark????????
 
From my readings and my latest High Performance ign systems,the ign system is one part of the motor that over kill will not harm engine performance. Now the authors also go on to point out that your basic stock motor will not benefit much from performance upgrades in the ign,but it will not hurt them either.
Ign upgrades are one of the most overlooked mods on a performance motor,remember with out the spark you are going no where.
 
kwplot34 said:
From my readings and my latest High Performance ign systems,the ign system is one part of the motor that over kill will not harm engine performance. Now the authors also go on to point out that your basic stock motor will not benefit much from performance upgrades in the ign,but it will not hurt them either.
Ign upgrades are one of the most overlooked mods on a performance motor,remember with out the spark you are going no where.
Click to expand...

Maybe it was my thread on my DUI upgrade which "sparked" this discussion.

I agree with Kevin on this one. I didn't realize how starved my engine was for a good ignition system. My engine was is a rebuilt 454 with a roller cam and forged bottom end and higher compression. I also had my points ignition rebuilt and upgraded, tayler plugs, yada, yada. The engine ran good, but had misfires at higher RPM's.

With the hotter spark and wider gap, there is a noticeable performance difference. It didn't add more horsepower...rather, the better ignition allows me to further reach the potential of my engine.
 
A point ignition system is going to cause misfire at higher engine speeds, just due to design. The points are going to bounce at some point. The offset was using bigger and bigger springs on the points. And sooner of later you get to saturation point on the coil- the points don't stay closed long enough for the coil to build voltage. I actually saw one set that broke the breaker plate out of the dizzy.
OK, so after that was HEI- 45,000 volts with a 12v input- that was seen as the savior- until they found the limits of the module/pickup coil.
The whiz kids worked out the math and got the multi spark working (the Model T had it first BTW!) with all different kinds of triggers. Photoelectric,(optical), magnetic impulse just for a couple.

With high compression, unless there's a good hot spark, it just blows it out (IMHO). Also where a wider plug gap is not that desireable. So now with high RPM, high compression, it's time to turn it up to 50,000.

trivia question-- What was the max voltage on some of the old Vertex mags? The faster you spin those the bigger the spark. And getting zapped by one of those (or an aircraft mag) is NOT on my "Fun things to do" list.
 
trivia question-- What was the max voltage on some of the old Vertex mags? The faster you spin those the bigger the spark. And getting zapped by one of those (or an aircraft mag) is NOT on my "Fun things to do" list.
__________________



Oh, BULLSHIT, REAL men grab the wire and blink their eyes when setting timing.....U woose....


:smash::smash::shocking::flash:
 
An average engine works fine with "X" volts to bridge the gap, and "X" joules of energy to create the "spark." At some point, it gets moot. I.E., a million volts and 50 amps will wear out a plug in seconds. There MUST be a point of "zero return." :quote:
A blasting cap will reliably ignite dynamite. 10 blasting caps does ZERO to aid the charge.;)
 
Bullshark said:
Wow, Bird, what prompted this. You looking for a thesis topic? :D
Just thinking out loud..... What ever it takes to reliably ignite the air/fuel charge under all the extremes of changing operating conditions i.e.;
engine temperature
A/F charge temperature
A/F ratio
rpm
MAP.. (engine load)
humidity
spark timing
VE
etc.
etc.
not to mention the fact that some of these parameters can, and do, rapidly change.

I vote for overkill. :smash: No real penalty that I can see off hand. :fishing: What deteriorates that causes faster detune? These days the only thing that comes to mind is the spark plug electrodes and they are pretty tough. (Don't forget I dumped mechanical points along time ago) :harhar: I probably wind up changing mine long before the electrodes deteriorate.

Your turn..:bump:

Bullshark
Click to expand...

This is the line of thinking I seek.
A top fuelie runs twin magneto ignition using 44 amps of energy to insure the ignition of a "nearly hydaulic lock" mixture of fuel. A misfire of one "spark" spells catastrophic failure. The plugs, due to the energy involved are "done" at the 700' line or so. Hardly reliable for a street machine.;)
A Model T Frod operating below 3,000RPM at 3.5 compression ratio works fine with 12,000 volts or less, and as Tim stated, uses multiple disharge sparks, almost 20* duration.:eek:
Higher voltages break down wire insulation due to the ozone generated at high voltage, and voltages generated above certain levels introduce spark scatter and dielectric breakdown of all parts concerned. Excessive saturation of coils (Dwell) creates excess heat that actually lessons it's output.
At SOME point, it becomes "pointless.":quote:
Anyone here study "Combustion Engeering?"
 
My two cents:

High voltage is usually just a marketing issue. The gap ionization voltage (arcover voltage) is what determines the maximum voltage that the system sees under normal operation. If a plug wire falls off, then the coil will automatically keep raising the voltage (due to the collapsing magnetic field) until something, somewhere arcs over and dissipates the energy stored in the coil. The high numbers (50 kV) you see in some advertising are just the dielectric strength of the winding segments. It has nothing to do with the most important item, the energy in the coil.
A wide gap is theoretically desirable. A wider gap will light off a larger percentage of the air/fuel mixture, theoretically causing a faster burn (and therefore requiring less advance). Most anything that reduces the advance required will result in increased pumping efficiency (due to the piston not having to spend as many crank degrees compressing a burning mixture).
The downside of a large gap, in my opinion, is the increased sensitivity to having the spark blown out (or the "string" of ionized gas in the gap broken up easier) due to chamber swirl, requiring the coil to ramp up in voltage again to re-spark the mixture. This delay in resparking can cause a minor amount of spark retard, along with energy losses as the system has to recharge up a bunch of parasitic capacitances distributed throughout the system.
As there is no free lunch in an ignition system, whenever the gap is increased, the spark duration is decreased. The energy in the coil is consumed by gap voltage X gap current X spark duration. More gap voltage, less spark duration.
The gap current is affected significantly by the system resistance (the coil windings, plug wire resistance, and the gap impedance). I suppose high current will potentially put more instantaneous wattage into the gap, but the spark duration will decrease, as I mentioned earlier, and plug electrode life usually suffers.
As far as what level of energy is overkill, I believe it depends on each engine's "personality". I've worked with some other ignition engineers who were responsible for mapping out the ignition requirements of a new engine. They would vary the energy levels of their test setup and monitor the engine looking for performance dropoff, emission issues, etc, and then spec out a coil to be used on the engine, and the primary current, dwell times, and open circuit clamping voltages that the ignition module would have to control.

Again, just my two cents.
 
I for one can tell you this,if you have a high performance ign system and if one of the parts are not up to the task,it will show up real fast. I found out real fast that the regular core wires will not last through 1 tank of fuel,so i put on better plug wires problem solved.I have ran my motor with a stock gm HEI before i put in all the upgrades,and there is a difference a noticeable difference.

And NO Gene my motor does not run rich!!!!!!!!!!!!
 
A wonderfull, insightfull response from someone who designed these systems.

1) Voltage means squat. "Energy does"

2) Ignition is a "system", and all "systems" have components that work in harmony "together."

I liken this to a quadrajet requiring 4lbs fuel pressure to operate. 10 lbs does zero, and is a detremenent.

I have also read where some "rare earth" plugs, such as Irridium, misfire at large gaps and high cylinder pressures.
 
kwplot34 said:
I for one can tell you this,if you have a high performance ign system and if one of the parts are not up to the task,it will show up real fast. I found out real fast that the regular core wires will not last through 1 tank of fuel,so i put on better plug wires problem solved.I have ran my motor with a stock gm HEI before i put in all the upgrades,and there is a difference a noticeable difference.

And NO Gene my motor does not run rich!!!!!!!!!!!!
Click to expand...

A stock GM HEI works fine for low compression values. It was designed to reduce tune up intervals, and 8.5 CR was norm at the time. You run much larger CR Kevin.

As Turbo stated, what works well for your ICE may not work as well for others.
 
BRUTAL64 said:
big2bird said:
Okay, so at what point is more spark "zero return?"
At some point, more is overkill, less reliable, and just detunes faster.:shocking:
Click to expand...

These are max volts--under heavy loads.
25,000 volts is consided pretty much stock norm.
40,000 to 45,000 volts is considered Hiperf.
So anything over 50,000 is considered overkill -- if there is such a thing.

This comes from my talks with Accel.:phone:


These are just general--and are max volts. Under light load it will be a much lower rating.:quote:

Do you want to talk mulit-spark????????
Click to expand...

This is typical aftermarket "hype" and BS.
 
big2bird said:
kwplot34 said:
I for one can tell you this,if you have a high performance ign system and if one of the parts are not up to the task,it will show up real fast. I found out real fast that the regular core wires will not last through 1 tank of fuel,so i put on better plug wires problem solved.I have ran my motor with a stock gm HEI before i put in all the upgrades,and there is a difference a noticeable difference.

And NO Gene my motor does not run rich!!!!!!!!!!!!
Click to expand...

A stock GM HEI works fine for low compression values. It was designed to reduce tune up intervals, and 8.5 CR was norm at the time. You run much larger CR Kevin.

As Turbo stated, what works well for your ICE may not work as well for others.
Click to expand...

You and Turbo are absolutely correct. You did notice in one of my post where i said in my reading up on this a while back that a pretty much stock motor will really gain no improvements with ign mods.
 
TimAT said:
A point ignition system is going to cause misfire at higher engine speeds, just due to design. The points are going to bounce at some point. The offset was using bigger and bigger springs on the points. And sooner of later you get to saturation point on the coil- the points don't stay closed long enough for the coil to build voltage. I actually saw one set that broke the breaker plate out of the dizzy.THAT is why dual points were the "state of the art" in old days. Increased dwell at higher RPM
OK, so after that was HEI- 45,000 volts with a 12v input- that was seen as the savior- until they found the limits of the module/pickup coil.
The whiz kids worked out the math and got the multi spark working (the Model T had it first BTW!) with all different kinds of triggers. Photoelectric,(optical), magnetic impulse just for a couple.

With high compression, unless there's a good hot spark, it just blows it out (IMHO). Also where a wider plug gap is not that desireable. So now with high RPM, high compression, it's time to turn it up to 50,000. YEP

trivia question-- What was the max voltage on some of the old Vertex mags? The faster you spin those the bigger the spark. And getting zapped by one of those (or an aircraft mag) is NOT on my "Fun things to do" list.
Click to expand...
I can't answer that for sure, but a magneto does have the advantage of increased spark energy at higher RPM's. The faster it spins, the more it puts out. "To a point."
They also have the "disadvantage" of incredible strain on the drivetrain. "LOT'S of rotating weight there."
 
69427 said:
My two cents:

High voltage is usually just a marketing issue. The gap ionization voltage (arcover voltage) is what determines the maximum voltage that the system sees under normal operation. If a plug wire falls off, then the coil will automatically keep raising the voltage (due to the collapsing magnetic field) until something, somewhere arcs over and dissipates the energy stored in the coil. The high numbers (50 kV) you see in some advertising are just the dielectric strength of the winding segments. It has nothing to do with the most important item, the energy in the coil.
A wide gap is theoretically desirable. A wider gap will light off a larger percentage of the air/fuel mixture, theoretically causing a faster burn (and therefore requiring less advance). Most anything that reduces the advance required will result in increased pumping efficiency (due to the piston not having to spend as many crank degrees compressing a burning mixture).
The downside of a large gap, in my opinion, is the increased sensitivity to having the spark blown out (or the "string" of ionized gas in the gap broken up easier) due to chamber swirl, requiring the coil to ramp up in voltage again to re-spark the mixture. This delay in resparking can cause a minor amount of spark retard, along with energy losses as the system has to recharge up a bunch of parasitic capacitances distributed throughout the system.
As there is no free lunch in an ignition system, whenever the gap is increased, the spark duration is decreased. The energy in the coil is consumed by gap voltage X gap current X spark duration. More gap voltage, less spark duration.
The gap current is affected significantly by the system resistance (the coil windings, plug wire resistance, and the gap impedance). I suppose high current will potentially put more instantaneous wattage into the gap, but the spark duration will decrease, as I mentioned earlier, and plug electrode life usually suffers.
As far as what level of energy is overkill, I believe it depends on each engine's "personality". I've worked with some other ignition engineers who were responsible for mapping out the ignition requirements of a new engine. They would vary the energy levels of their test setup and monitor the engine looking for performance dropoff, emission issues, etc, and then spec out a coil to be used on the engine, and the primary current, dwell times, and open circuit clamping voltages that the ignition module would have to control.

Again, just my two cents.
Click to expand...

Hey Mikey, I like it......

It's the area under the curve.....

:smash::bump:
 
69427 said:
My two cents:

High voltage is usually just a marketing issue. The gap ionization voltage (arcover voltage) is what determines the maximum voltage that the system sees under normal operation. If a plug wire falls off, then the coil will automatically keep raising the voltage (due to the collapsing magnetic field) until something, somewhere arcs over and dissipates the energy stored in the coil. The high numbers (50 kV) you see in some advertising are just the dielectric strength of the winding segments. It has nothing to do with the most important item, the energy in the coil.
A wide gap is theoretically desirable. A wider gap will light off a larger percentage of the air/fuel mixture, theoretically causing a faster burn (and therefore requiring less advance). Most anything that reduces the advance required will result in increased pumping efficiency (due to the piston not having to spend as many crank degrees compressing a burning mixture).
The downside of a large gap, in my opinion, is the increased sensitivity to having the spark blown out (or the "string" of ionized gas in the gap broken up easier) due to chamber swirl, requiring the coil to ramp up in voltage again to re-spark the mixture. This delay in resparking can cause a minor amount of spark retard, along with energy losses as the system has to recharge up a bunch of parasitic capacitances distributed throughout the system.
As there is no free lunch in an ignition system, whenever the gap is increased, the spark duration is decreased. The energy in the coil is consumed by gap voltage X gap current X spark duration. More gap voltage, less spark duration.
The gap current is affected significantly by the system resistance (the coil windings, plug wire resistance, and the gap impedance). I suppose high current will potentially put more instantaneous wattage into the gap, but the spark duration will decrease, as I mentioned earlier, and plug electrode life usually suffers.
As far as what level of energy is overkill, I believe it depends on each engine's "personality". I've worked with some other ignition engineers who were responsible for mapping out the ignition requirements of a new engine. They would vary the energy levels of their test setup and monitor the engine looking for performance dropoff, emission issues, etc, and then spec out a coil to be used on the engine, and the primary current, dwell times, and open circuit clamping voltages that the ignition module would have to control.

Again, just my two cents.
Click to expand...

Your, two cents is well put.:cool:

Good stuff!!!!!
 
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