I may do it after the bad weather passes. I really do have a briggs and stratton question. LOL
Testing the HiRev 7500
- Thread starter Newbomb Turk
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Dave999
Well-Known Member
Inductance and of course impedance/reactance/reluctance.... 2 coils linked by a core one potentially wound over the top of the other....
if you can do the calculations necessary to cover this off in more detail than
"a higher current fills the coil faster"
by all means........
Last time i had to worry about that stuff was for 1.5 hours in 1992...and i squeezed a pass at the pass mark of 40%... i.e I knew just enough to be dangerous, but got 60% of it wrong.... i have continued in much the same vein for the last 30 years
Dave
if you can do the calculations necessary to cover this off in more detail than
"a higher current fills the coil faster"
by all means........
Last time i had to worry about that stuff was for 1.5 hours in 1992...and i squeezed a pass at the pass mark of 40%... i.e I knew just enough to be dangerous, but got 60% of it wrong.... i have continued in much the same vein for the last 30 years
Dave
Mattax
Just the facts, ma'am
For the readers who aren't following the fuss over semantics of starting a flame (and are curious).\
Spark Voltage and Current.
Voltage is difference in energy levels between two points in a circuit.
At the tip of the spark plug, the voltage required to jump the gap varies with distance and condition of the plug and conditions inside the chamber. Dirty plug, wider gap, poor fuel-air-dilution conditions will require more voltage to jump the gap or 'initiate' the spark.
Current is electrons moving.
0.5 amps at 12 Volts won't hurt you. 200 amps at 12 volts will hurt you!
If your tap water or well pump has the pressure into the house at 100 psi, and you crack a faucet open, thats like a trickle of current. If you turn it it wide open, lots of current.
So that is the context when "Dr" Jacobs wrote voltage doesn't create a spark. Of course there are some electrons moving when the spark initates. Once the first electrons have jumped the gap, then less voltage is needed to keep the current flowing. The current will continue flowing as long as there is enough energy from the coil but its only needed until the fuel around the gap is burning on its own. If you've ever started a fire with a match or flint and steel, that's a good analogy of preparing the tinder and kindling. The better the tinder and kindling has been prepared, the more likely a spark from the flint and steel will do. The less well prepared, the more likely a Zippo will have to be used and held on the kindling for a long time.
An osilliscope can capture the voltage in the spark plug wires.
The firing voltage is the voltage needed to jump the gap. It's going to be something like 10, 15, 20 KV. The book this illustration came from they didn't provide a scale of how many kV per division.
Once the current is flowing (electrons jumping the gap) less voltage is needed to get them across the gap. That's the spark burn line voltage.
When the spark is done, there is some 'ringing' in the system. Kindof like when shutting a water valve quick, we'll often hear the impact of the flow being cut off hard.
Combustion Flame
Let's make this simple as possible.
When the fuel and air around the spark begin to burn as a kernal of flame.
With all of the air mix swirling and tumbling around, there is a brief period where this flame can go out.
Things that can contribute to this are shadows created by the combustion chamber around the spark plug tip, a cold chamber, a lack of easily ignited hydrocrabons (eg old fuel, or using summer fuel in the winter), exhaust dilution, etc.
The longer the spark can continue, the more likely the kernal will grow in spite of poor conditions.
Also, for a given voltage, the stronger the current, the more energy going into the spark. In other words the spark will be hotter (because the energy here is getting converted mostly into heat).
Years ago Shrinker posted several detailed descriptions of this process. If I can find a link that still works, I'll post it here.
Bottom Line
The more difficult we make the conditions for combustion to begin, the more we have to ask our ignitions to help get a good burn started. It doesn't matter if we are doing this for emissions, or fuel, or exhaust dilution. It's true we can cover our sins or do things the engine wouldn't normally like to do (like lean burns at idle rpms) with some of the fancy stuff that's come along after points.
But in my opinion, nothing substitutes for getting the timing correct for the rpm and load. This is why I hammer those examples from the factory teams and guys who are or were running stock eliminator.
Spark Voltage and Current.
Voltage is difference in energy levels between two points in a circuit.
At the tip of the spark plug, the voltage required to jump the gap varies with distance and condition of the plug and conditions inside the chamber. Dirty plug, wider gap, poor fuel-air-dilution conditions will require more voltage to jump the gap or 'initiate' the spark.
Current is electrons moving.
0.5 amps at 12 Volts won't hurt you. 200 amps at 12 volts will hurt you!
If your tap water or well pump has the pressure into the house at 100 psi, and you crack a faucet open, thats like a trickle of current. If you turn it it wide open, lots of current.
So that is the context when "Dr" Jacobs wrote voltage doesn't create a spark. Of course there are some electrons moving when the spark initates. Once the first electrons have jumped the gap, then less voltage is needed to keep the current flowing. The current will continue flowing as long as there is enough energy from the coil but its only needed until the fuel around the gap is burning on its own. If you've ever started a fire with a match or flint and steel, that's a good analogy of preparing the tinder and kindling. The better the tinder and kindling has been prepared, the more likely a spark from the flint and steel will do. The less well prepared, the more likely a Zippo will have to be used and held on the kindling for a long time.
An osilliscope can capture the voltage in the spark plug wires.
The firing voltage is the voltage needed to jump the gap. It's going to be something like 10, 15, 20 KV. The book this illustration came from they didn't provide a scale of how many kV per division.
Once the current is flowing (electrons jumping the gap) less voltage is needed to get them across the gap. That's the spark burn line voltage.
When the spark is done, there is some 'ringing' in the system. Kindof like when shutting a water valve quick, we'll often hear the impact of the flow being cut off hard.
Combustion Flame
Let's make this simple as possible.
When the fuel and air around the spark begin to burn as a kernal of flame.
With all of the air mix swirling and tumbling around, there is a brief period where this flame can go out.
Things that can contribute to this are shadows created by the combustion chamber around the spark plug tip, a cold chamber, a lack of easily ignited hydrocrabons (eg old fuel, or using summer fuel in the winter), exhaust dilution, etc.
The longer the spark can continue, the more likely the kernal will grow in spite of poor conditions.
Also, for a given voltage, the stronger the current, the more energy going into the spark. In other words the spark will be hotter (because the energy here is getting converted mostly into heat).
Years ago Shrinker posted several detailed descriptions of this process. If I can find a link that still works, I'll post it here.
Bottom Line
The more difficult we make the conditions for combustion to begin, the more we have to ask our ignitions to help get a good burn started. It doesn't matter if we are doing this for emissions, or fuel, or exhaust dilution. It's true we can cover our sins or do things the engine wouldn't normally like to do (like lean burns at idle rpms) with some of the fancy stuff that's come along after points.
But in my opinion, nothing substitutes for getting the timing correct for the rpm and load. This is why I hammer those examples from the factory teams and guys who are or were running stock eliminator.
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Dave999
Well-Known Member
Oh you nearly tempted me to get into joules per coulomb and coulombs per second
you have to create a plasma
and then use the fact that a plasma is conductive to maintain the spark
creating the plasma takes more voltage than maintaining the plasma
a spark travels through a plasma
no plasma .... no spark they go hand in hand.
plasma: ionised mixture with many free to move charged particles
the voltage needs to be high enough to cause the ionisation. electrons must be ripped from their safe moorings around the atoms that make up the molecules compressed in between the plug electrodes to create the plasma....
the plasma is the conductor between the electrodes that allows the spark.
the 4th state of matter
solid, liquid, gas....plasma... stars are full of it.. its quite common, just not round here.
sorry i have now truly disappeared up my own backside
Dave
you have to create a plasma
and then use the fact that a plasma is conductive to maintain the spark
creating the plasma takes more voltage than maintaining the plasma
a spark travels through a plasma
no plasma .... no spark they go hand in hand.
plasma: ionised mixture with many free to move charged particles
the voltage needs to be high enough to cause the ionisation. electrons must be ripped from their safe moorings around the atoms that make up the molecules compressed in between the plug electrodes to create the plasma....
the plasma is the conductor between the electrodes that allows the spark.
the 4th state of matter
solid, liquid, gas....plasma... stars are full of it.. its quite common, just not round here.
sorry i have now truly disappeared up my own backside
Dave
All I have to add is, if you don't think voltage has anything to do with jumping the gap, try it with zero. It takes BOTH.
Which was exactly the point of my video.
But the usual bullshitters come along, adding nothing.
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mopowers
Well-Known Member
Dave999
Well-Known Member
Oxygen from the air is "reduced"
The organic chemicals in the mixture that makes up the fuel are "oxidised"
happens quickly, rapid release of energy as heat,
bloody electrons again.... man they get everywhere.
D
The organic chemicals in the mixture that makes up the fuel are "oxidised"
happens quickly, rapid release of energy as heat,
bloody electrons again.... man they get everywhere.
D
FBO's claim on their box
"Eliminates Ballast Resistor, 44KV Output on demand, Plug and Play, one simple wiring modification (Eliminate Ballast Resistor, Kit Included), stock mounting, External Algorithm Dial Type POSITIVE STOP REV Limiter, 6061 billet aluminum CnC machined case, will not retard timing or drop output to: 7,000 RPM."
"Eliminates Ballast Resistor, 44KV Output on demand, Plug and Play, one simple wiring modification (Eliminate Ballast Resistor, Kit Included), stock mounting, External Algorithm Dial Type POSITIVE STOP REV Limiter, 6061 billet aluminum CnC machined case, will not retard timing or drop output to: 7,000 RPM."
If someone sends me the FBO box I'll test it. Or maybe send it to Bewy or 92b and let them test it. I for one would love to see their results ands if they differ from mine.
What else does it do? 12 volts and good to 7,000. Is that it?
Mattax
Just the facts, ma'am
There have been ways to work around the slew internally. It costs money of course. Probably Kit Carlson was explaining some of it.
Maybe tommorrow I'll dig up links to the old posts if someone else hasn't hasn't already done so.
One aftermarket company (might have been Hi-rev, might have been FBO) had a patent - so what they were doing (or trying to do) was no secret.
Maybe tommorrow I'll dig up links to the old posts if someone else hasn't hasn't already done so.
One aftermarket company (might have been Hi-rev, might have been FBO) had a patent - so what they were doing (or trying to do) was no secret.
If you mean the FBO box, it also has a rev limiter, eliminates the ballast resistor
It'll never happen. They'll sure argue you down all day though.
People have also eliminated the ballast for decades by just bypassing it with no ill effects. Not that I'm recommending it, but it's been done a lot.
It comes in an aluminum cnc cut box? If it's like his advance plates, I ain't impressed already.
Turk,
You were the clown that introduced a 3 amp magneto into this website [ in another thread, via a Spud Miller video ] with your claim that it gives a 'hotter spark than HEI'. Where is the example of a 3 amp mag firing 2500 hp, your claim post #72? Maybe with a 44 amp mag....I do not have to prove anything, you are the one making THIS claim.
You can do all the name calling you like to derail the truth & the ignorant like Mopowers will follow you like lap dogs, but the smart people on this forum will not.
I see Spud has modified a 3 amp mag to produce 4 amps pri current. The peak spark current is 47 mA, less that a quarter of a HEI system at 200 mA. And I am not seeing garbage bins littered with used HEIs....because they have been replaced with 'hotter spark' magnetos...
You were the clown that introduced a 3 amp magneto into this website [ in another thread, via a Spud Miller video ] with your claim that it gives a 'hotter spark than HEI'. Where is the example of a 3 amp mag firing 2500 hp, your claim post #72? Maybe with a 44 amp mag....I do not have to prove anything, you are the one making THIS claim.
You can do all the name calling you like to derail the truth & the ignorant like Mopowers will follow you like lap dogs, but the smart people on this forum will not.
I see Spud has modified a 3 amp mag to produce 4 amps pri current. The peak spark current is 47 mA, less that a quarter of a HEI system at 200 mA. And I am not seeing garbage bins littered with used HEIs....because they have been replaced with 'hotter spark' magnetos...
Sounds like a good idea to me. Working together will benefit all of us. When you say "test it" what exactly will we be testing and how?
I would say see his testing videos for instructions.
Saw the video. What distributor are we using for the fbo? locked I assume? What voltage are we supplying to the box? What coil are we using? What gap are we firing? And what are we looking for? Timing retard? RPM that the spark gets sketchy? At what gap? What sparkplugs are we using? what timing light? Plug wires? I want to make sure we use the same test procedure is there anything else?
Mattax
Just the facts, ma'am
The only 'catalyst' in this thread is you Geoff. Somehow you are never consumed, just like the gasoline you burn.
Just like we learned in scouts.
In the right quantities Fuel + O2 + heat => fire
The fuel gets consumed in the process creating various quantities of NOx C and CO and CO2 etc
Give it a break Geoff. You went off-track with some hyperbole to make your point, and people thought it was funny because it was ridiculous. Let it go.
Mattax
Just the facts, ma'am
Here's the links
Pertronix III may also account for slew. Do a search of @Kit Carlson posts for timing. He's posted how this is done electronicly so its less than degree.
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