sparkplug indexing
- Thread starter Kansas Bad Man
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Getting back to the thread of sparkplug indexing, little has been said as to the effect of spark INTENSITY and its effect on the quality of the burn. In here lye's
the scientific reasoning of the miner gain in horse power by indexing in most cases. Ambient Temperature, Humidity, Altitude and the fuel octane number effect the fuel/ air ratio in some cases moment by moment and most certainly hour by hour, This constant fuel/ air ratio change effects the heat primarily of the center electrode . This is the smallest metal mass in the combustion chamber and the easiest to absorb the heat of combustion. The tuner has in his tool box
four things that effects the kernel of intensity (spark) required to provide the initial ignition, having enough kernel size for complete combustion of the varying fuel/ air mixtures. The most important is ignition advance, a 10 degree advance raises the center sparkplug electrode temperature by 70 to 100 degree 'C'. Next is the heat ranges of the sparkplugs ,which controls the heat of the center electrode. The multiple electrode designs effect both center and ground electrodes , They are designed to enhance the size of the spark kernel and its intensity. When a single exposed electrode to the combustion is used ,its neutralizing effect to the varying fuel/ air ratios producing various amounts of heat to the combustion chamber is accomplished by indexing. This helps control the heat of the center electrode.
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the scientific reasoning of the miner gain in horse power by indexing in most cases. Ambient Temperature, Humidity, Altitude and the fuel octane number effect the fuel/ air ratio in some cases moment by moment and most certainly hour by hour, This constant fuel/ air ratio change effects the heat primarily of the center electrode . This is the smallest metal mass in the combustion chamber and the easiest to absorb the heat of combustion. The tuner has in his tool box
four things that effects the kernel of intensity (spark) required to provide the initial ignition, having enough kernel size for complete combustion of the varying fuel/ air mixtures. The most important is ignition advance, a 10 degree advance raises the center sparkplug electrode temperature by 70 to 100 degree 'C'. Next is the heat ranges of the sparkplugs ,which controls the heat of the center electrode. The multiple electrode designs effect both center and ground electrodes , They are designed to enhance the size of the spark kernel and its intensity. When a single exposed electrode to the combustion is used ,its neutralizing effect to the varying fuel/ air ratios producing various amounts of heat to the combustion chamber is accomplished by indexing. This helps control the heat of the center electrode.
MORE LATER
The three main fuels used in an internal combustion 4 stroke gas powered engine are gas, alcohol, nitro, often in combination. A simple experiment
that can be performed in the garage that gives you the idea of the different fuels mentioned characteristics of evaporation , burn time , and ignition temperature, amount of kernel intensity to ignite. To conduct the experiment, pour a thimble full of each fuel samples on the concrete floor, with a match , ignite and observe the reaction of the different fuels. First you will notice that gasoline evaporates the fastest, next comes alcohol, then nitro. When the match is put to the gasoline the ignition takes place prior to touching the liquid , the fumes light first, the accelerating burn is rapid making a sound and the flame is a red yellow color. The
characteristic of alcohol is much different, the match has to practically touch the puddle of alcohol before ignition, the acceleration of the burn is noticeably much slower, the flame is transparent to a light blue. When it comes to nitro, if you quickly put a burning match in the puddle ,at times it will extinguish the fire. Nitro needs the pre heating caused by compression to have a evaporation process for ignition . There is no such thing as 100 % nitro
the closest to 100% is the nitro refined in China, which is 97% measured with a hydrometer to determine the specific gravity which gives you the % its a weight and temperature thing to determine what you have. Additives such as propylene oxide and alcohol are the most common igniters that are added to nitro to aid in ignition. It takes a large intensity ignition kernel to ignite nitro , and ignition that has a high duration factor is also must.
The gasoline today is a blend of gasoline and alcohol at most pumps . To run these fuels you must run a richer main jet then you would have run when leaded fuels were the norm. The reason is the alcohol in the blind requires less oxygen per volume for a proper fuel / air mixture.
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that can be performed in the garage that gives you the idea of the different fuels mentioned characteristics of evaporation , burn time , and ignition temperature, amount of kernel intensity to ignite. To conduct the experiment, pour a thimble full of each fuel samples on the concrete floor, with a match , ignite and observe the reaction of the different fuels. First you will notice that gasoline evaporates the fastest, next comes alcohol, then nitro. When the match is put to the gasoline the ignition takes place prior to touching the liquid , the fumes light first, the accelerating burn is rapid making a sound and the flame is a red yellow color. The
characteristic of alcohol is much different, the match has to practically touch the puddle of alcohol before ignition, the acceleration of the burn is noticeably much slower, the flame is transparent to a light blue. When it comes to nitro, if you quickly put a burning match in the puddle ,at times it will extinguish the fire. Nitro needs the pre heating caused by compression to have a evaporation process for ignition . There is no such thing as 100 % nitro
the closest to 100% is the nitro refined in China, which is 97% measured with a hydrometer to determine the specific gravity which gives you the % its a weight and temperature thing to determine what you have. Additives such as propylene oxide and alcohol are the most common igniters that are added to nitro to aid in ignition. It takes a large intensity ignition kernel to ignite nitro , and ignition that has a high duration factor is also must.
The gasoline today is a blend of gasoline and alcohol at most pumps . To run these fuels you must run a richer main jet then you would have run when leaded fuels were the norm. The reason is the alcohol in the blind requires less oxygen per volume for a proper fuel / air mixture.
MORE LATER
Don't forget to take the bikes out of the Garage First !! Good Fun Max, Cheers Bill.
I worked at Conways in 1965 ish, On a cold day there was a Paraffin fire in the middle of the workshop, We had runout of Pariffin so one of the lads said he wood light it with Petrol !! I said to him "It's Not The Same !! " And I went and stood at the door, Whoosh Clear to the Roof !! Cheers Bill.
Magnetos have a high intensity spark but of short duration, good for jumping high density plug gaps. Not good for high %s of nitro, to make a point, you cant ignite a Oak tree by passing a blow torch over its trunk quickly. Hence the need for long duration ignition for some fuel systems. Inductive ignition systems
has been around since 1908, Charles Kettering sp? developed it. The coils used were able to provide high intensity spark, capable of jumping high density
sparkplugs electrode gaps, but short in duration. The inductive system has been improved resonantly by the introduction of insolated bipolar gate
transistors ( IGBT ) these have allowed the development of extremely accurate high intensity spark inductive ignition systems. The most significant
of the INDUCTIVE ignition system is that inductive coils are more efficient capacitive discharge coils as they can provide a longer spark duration
that insures complete combustion of the fuel. Little of the coils energy is used to jump the electrode gap, leaving energy to prolong the spark duration.
MORE LATER
has been around since 1908, Charles Kettering sp? developed it. The coils used were able to provide high intensity spark, capable of jumping high density
sparkplugs electrode gaps, but short in duration. The inductive system has been improved resonantly by the introduction of insolated bipolar gate
transistors ( IGBT ) these have allowed the development of extremely accurate high intensity spark inductive ignition systems. The most significant
of the INDUCTIVE ignition system is that inductive coils are more efficient capacitive discharge coils as they can provide a longer spark duration
that insures complete combustion of the fuel. Little of the coils energy is used to jump the electrode gap, leaving energy to prolong the spark duration.
MORE LATER
Before responding I was waiting to see if what you wrote later allowed me to understand what you meant by the above, as well as in what way you were hoping to try to tie the other stuff in this particular post to indexing. But you then went even further off topic with your subsequent posts.
This and subequent posts present a problem. It serves no purpose for people to respond to individual incorrect items scattered through a post with "no you're wrong," without explaining why you are wrong. But, you have been writing wrong things faster than I have time to provide details of why they are wrong. So, since this thread is about indexing spark plugs, my own way of dealing with this problem will be if/when you do write something that directly relates to whether or not indexing provides a 1% h.p. gain I'll respond to that. Otherwise, not.
As I said in the first paragraph, although you used the word "indexing" in the text I quoted above, I don't understand what you were trying to say, so I can't respond to it. Please explain.
There are 4 factors that contribute to the combustion chambers heat. The metal parts are cooled (on a Vincent) by its finning, by a ever changing proper fuel/ air
ratio, meaning that the sparkplug heat range selected is not to hot or to cold to cope with the varying btu factor. and the cooling effect of the fuel/ air velocity wash during the intake cycle. The intake manifold, the intake valve, the combustion chamber and the center electrode of a single electrode design if the open end of the ground electrode is pointed toward the fuel /air wash. This cooling effect by the wash is not good as it is not constant in its amount of cooling btu's .
The center electrode already has its work cut out for it to hold a temperature that doesn't change the fixed mechanical timing of ignition to a point where the timing is advanced to a point beyond the best point of the fuel burn expansion . Remember , it is the fact that if the advance of the ignition by 10 degrees changes the center electrode by 70 to 100 degree C, what I said is the same thing only in reverse. The many sparkplug designs that hide the center electrode from the fuel/air velocity cooling wash in effect is serving the intent of purpose of indexing the sparkplug.
CHEERS ----- MAX
ratio, meaning that the sparkplug heat range selected is not to hot or to cold to cope with the varying btu factor. and the cooling effect of the fuel/ air velocity wash during the intake cycle. The intake manifold, the intake valve, the combustion chamber and the center electrode of a single electrode design if the open end of the ground electrode is pointed toward the fuel /air wash. This cooling effect by the wash is not good as it is not constant in its amount of cooling btu's .
The center electrode already has its work cut out for it to hold a temperature that doesn't change the fixed mechanical timing of ignition to a point where the timing is advanced to a point beyond the best point of the fuel burn expansion . Remember , it is the fact that if the advance of the ignition by 10 degrees changes the center electrode by 70 to 100 degree C, what I said is the same thing only in reverse. The many sparkplug designs that hide the center electrode from the fuel/air velocity cooling wash in effect is serving the intent of purpose of indexing the sparkplug.
CHEERS ----- MAX
No, this is quite wrong. You can't swap cause and effect and hope that the logic works, because it doesn't. Cause: the sun comes up. Effect: it gets light in your room. This is a fact but it does not mean that if you flip the switch on your desk lamp tonight it will cause the sun to rise.
As long as the plug's electrode isn't so hot that it causes pre-ignition, increasing or decreasing the temperature of the electrode has no effect on the timing. The spark happens, and ignition starts, when the points open irrespective of the temperature of the electrode.
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