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I would avoid running anything MSD in your ignition system. They have an extremely high failure rate. I laughed my ass off during 2 different episodes of the TV show Pinks, where 2 different cars had problems on the show after their MSD systems crapped out on camera.
Run MSD 6a box and full ignition here. The high failure rates are not on the sports compact boxes. In 2 years, only problem I had was an ignition box failure because my dumbass didn't cover it well enough when cleaning the engine bay.
MSD replaced it for free under their warranty even though was my fault, then i paid 40 for them to fix the broken one and now have a spare box. Spray it with some silicone before you install on the boxand coil, use their spark lube where indicated and I advise getting the external noise canceling capacitor if you plan on mounting the box on your firewall because it will interfere with your AM, FM and wireless receiver on car alarm
and i can name em right back atcha, your point? The most common reoccurrence with high voltage ignition failures are improper spark plugs. If you use a slower burning or less conductive spark with a high output ignition its asking for trouble. The tech lines will tell you this when you order over the phone that's the only thing I can see causing premature ignition failures. use copper or those pulse plugs with aftermarket ignitions
If you use a slower burning or less conductive spark with a high output ignition its asking for trouble.
There is no such concept as either a "slower burning spark" or "less conductive spark". The burn speed is a factor of many things, primarily in-cylinder fuel distribution, combustion chamber configuration, and piston geometry. It has virtually nothing at all to do with the spark plug, at least in something that end-users would see in a spark-ignition engine.
"less conductive spark" is a meaningless term. The conductivity of air is just nearly fixed. There is a concept of conductivity in a spark plug; there are resistor versions and non-resistor versions. Non-resistor applications are quite rare, and the failures I have seen of the MSD boxes have nothing to do with non-resistor plugs.
Back to the original argument, the MSD boxes most definitely do fail on a regular basis. This is because their manufacturing quality control is terrible. I have seen more than one of them on a bench with blown out components because of this.
umm im going to point you towards contacting spark plug companies yourself, but you saying iridium and platinum have same conductivity as copper is elementally false and im sorry whomever gave you that impression.
for reference sake, electrons leap away from the tip of a small-diameter, sharp-edged wire far more willingly than from one that's fatter and rounded. So the fine-wire plug requires less voltage to form a spark than one with conventional electrodes, and the difference becomes increasingly biased in the former's favor as hours in service accumulate and erosion blunts the iron-alloy electrodes. So while these more precious metal plugs may last longer because they work a bit slower there are considerable drawbacks with precious-metal plugs: they are more expensive, and they are very sensitive to excessive ignition advance. iow, higher voltage ignitions that spark faster than the plug's physical attributes want to. The overheating you get with too much spark lead effects plugs' center electrodes before it can be detected elsewhere in an engine, and when subjected to this kind of mistreatment fine-wire electrodes simply melt. In one sense this is a disadvantage, as it means ruining expensive spark plugs. Seen in another way it's a bonus feature: it is better to melt a plug electrode than an engine. So there is a balance in it but there are blow back effects of using lesser conductive metals.
I really think you are missing what spark plug metals exist for, saying that "less conductive spark" doesnt exist is pretty ignorant. Copper conducts a hell of a lot more than any other metal except for silver. Conductivity is the reciprocal of electrical resistivity and has the SI units of siemens per meter. SO: if the electrical conductance between opposite faces of a 1-metre cube of material is 1 siemens then the material's electrical conductivity is 1 siemens per meter.
So yes by using the MSD ignition box you are VERY much directly changing the ignition, hence why HHO and e85 supplements really love higher voltage ignitions because a HUGE amount more of the a/f that enters the combustion chamber ignites thus less emissions, and you can drop your fuel pressure increasing gas mileage. That's the kind of applications we work with here.
So if one puts in a full MSD ignition (box, coil, cap & rotor, then wires) but puts on a restrictive spark you negate everything, think of the back wash effect. HOWEVER, if one puts on a more conductive plug to compliment what the ignition is feeding to it, BAM everything then works in harmony.
There is also a good tech line where you actually talk to somebody besides a customer service rep so if my definitions confuse you or you don't get em...well sorry just did a lot of research of copper alloys with brass production and spark plugs for my old capstone class in school so they can prolly make it mean more to you.
for reference sake, electrons leap away from the tip of a small-diameter, sharp-edged wire far more willingly than from one that's fatter and rounded. So the fine-wire plug requires less voltage to form a spark than one with conventional electrodes, and the difference becomes increasingly biased in the former's favor as hours in service accumulate and erosion blunts the iron-alloy electrodes.
This is not in dispute. However, the actual difference you get in combustion between a fine-wire plug and a regular plug is very small. Fundamentally, everything burns the same way, and any difference is usually within a degree or two of ignition advance.
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So while these more precious metal plugs may last longer because they work a bit slower there are considerable drawbacks with precious-metal plugs: they are more expensive, and they are very sensitive to excessive ignition advance. iow, higher voltage ignitions that spark faster than the plug's physical attributes want to. The overheating you get with too much spark lead effects plugs' center electrodes before it can be detected elsewhere in an engine, and when subjected to this kind of mistreatment fine-wire electrodes simply melt. In one sense this is a disadvantage, as it means ruining expensive spark plugs. Seen in another way it's a bonus feature: it is better to melt a plug electrode than an engine. So there is a balance in it but there are blow back effects of using lesser conductive metals.
This information is patently false. Yes, there are differences in the conductivity of copper, iridium, and platinum. Just to explain my point, here is there resistance values:
copper : 1.7 x 10^-8 ohm-m
iridium : 4.7 x 10^-8 ohm-m
platinum : 1.1 x 10^-7 ohm-m
Now, these values are unbelievably low. There are 3 important considerations to remember here:
1) The actual distance comprising this resistivity is on the order of > 5 mm
2) All automotive sparkplugs have a built-in resistor of 5kohm.
3) All automotive wires have a resistance of approx. 1kohm (some variability here)
Given the inherent and designed-in resistance of wires and plugs at 6kohms or more, the conductivity of the actual electrode becomes truly inconsequential. It makes no difference on the formation of the spark. For 2 plugs with the same electrode geometry and different composition, they will ignite fuel exactly the same.
The purpose of using metals such as iridium and platinum are to reduce the geometry effects of ignition wear. This is how you can run longer change intervals over using just copper plugs.
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So yes by using the MSD ignition box you are VERY much directly changing the ignition, hence why HHO and e85 supplements really love higher voltage ignitions because a HUGE amount more of the a/f that enters the combustion chamber ignites thus less emissions, and you can drop your fuel pressure increasing gas mileage. That's the kind of applications we work with here.
I'm not sure why you are arguing about this; I am aware that ignition amplifiers can do good in most engines.
You keep referring to something called a "restrictive spark", and I don't know what you mean. Other than the small selection of different spark plugs available, nothing is more or less restrictive than another.
This information is patently false. Yes, there are differences in the conductivity of copper, iridium, and platinum. Just to explain my point, here is there resistance values:
copper : 1.7 x 10^-8 ohm-m
iridium : 4.7 x 10^-8 ohm-m
platinum : 1.1 x 10^-7 ohm-m
Now, these values are unbelievably low. There are 3 important considerations to remember here:
1) The actual distance comprising this resistivity is on the order of > 5 mm
2) All automotive sparkplugs have a built-in resistor of 5kohm.
3) All automotive wires have a resistance of approx. 1kohm (some variability here)
yes the geometry of the electrodes have importance with the current and the following ignition inside the chamber, but they are tipped with these different metals, and denso's super narroe .4mm electrodes tipped with iridium make up for the lackings in platinum and iridium with high voltage applications. The reason that stock ignitions adapt so well to these 2 alloys is because they require apx 5000v less to get same results as the heat and transfer going on with copper. Copper does more, runs hotter and thus just doesn't last as long. But when you are running helical copper cores through wires with 45,000v shooting out the coil, you have opposite forces working in your combustion chamber. If your plug is wanting to use less voltage, thus making the stock coil work less because it is doing double duty. There is your restrictive voltage on stock coils, and the restriction with iridium and platinum plugs with highly conductive ignitions.
The trick is to keep the electrodes hot enough to burn off fouling deposits but not so hot that they cause preignition. (Which is what happens with iridium and platinum with 45,000v and more shooting at them) To burn off carbon deposits, the center electrode needs to reach about 700 degrees F quickly. But if it gets too hot (above -1,500 degrees F depending on the plug design), it may ignite the fuel before the spark occurs, causing preignition and detonation. For most plugs, the ideal operating temperature is around 1,200 degrees F, this is the case with all plugs also. Thus, there's your reason why you do not use those plugs with performance ignitions. Remember the plugs are not creating the heat, they work as the heat exchanger pulling the left over thermal energy out and into the cooling system. I should also add that the longevity factor is also in part because they ignite for a very miniscule period so naturally requiring less voltage and working faster because of the geometry as you mentioned stock setups really enjoy the iridium and platinum plugs. However, with the much lesser resistance through the wires to the plug and then rather than 6kohm meeting half that with the resistor plugs or the pulse plug ends there is more going through. The way those pulse circuits really work is by getting as much of the ignition current into the chamber and igniting it even faster, i believe the number was .2nanoseconds, hence why it ignites more and allows the user to tone down the fp.
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Originally Posted by Artifex
Given the inherent and designed-in resistance of wires and plugs at 6kohms or more, the conductivity of the actual electrode becomes truly inconsequential.
MSD wires have resistances 40-50ohms. And since they make their stuff to work in tandem, 6000ohms and more resistance as you speak of...im just lost there. But yes, with that much resistance sure it would negate anything coming into it. But we both know ignition setups over come that kinda resistance that may exist on stock setups, but still 6kohms is alot im not sure where you got that number but feel free to show me.
Quote:
Originally Posted by Artifex
It makes no difference on the formation of the spark. For 2 plugs with the same electrode geometry and different composition, they will ignite fuel exactly the same.
No, denso on their site attests to this, iridium or double-platinum or copper with super narrow electrodes and identical gaps perform at different temperatures and ignite differently.
At any rate, you make valid points but its all being negated by the msd ignition the #s you represent arent the same for their parts. I'm gonna try to get in contact with Joe over there again as he helped me getting my setup 2 years back and was pretty knowledgeable on this subject coming from working with NGK i think he said about 10 years in R&D so I will leave his extension a message and drop an email to him linking him to this thread and see if he can clarify why Nology and MSD both say to use copper plugs over the longer lasting plugs with their setups.
...not to get off the topic but while you guys are at it... which plug is the best for stock except for intake/exhaust... yes i read it but you guys are on another level of terms for me to understand. (not in a dick way just confused)
sorry about the errors just typing it fast not thinking it was a big deal . lol you guys kill me
...not to get off the topic but while you guys are at it... which plug is the best for stock except for intake/exhaust... yes i read it but you guys are on another level of terms for me to understand. (not in a dick way just confused)
sorry about the errors just typing it fast not thinking it was a big deal . lol you guys kill me
like we were saying, platinum and iridium from denso and ngk are loved by our car because the stock coil is doing so much already these require less volts to work well enough for your purposes and last a long while. So whatever is cheapest at your neighborhood autozone, i always go NGK but that's just my personal preference
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Still waiting on a call back from Joe, i want a definitive answer why they always say copper is best cuse we got points for and against it and the msd ignition failures.
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