NGK IRIDIUM IX Resistor Spark Plugs overheating coils?

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jimbo

jimbo

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I just talked to a ignition expert. I mentioned I thought I had a intermittent coil problem. Then I mentioned I had NGK IRIDIUM IX Resistor Spark Plugs and he said that those plugs have a real high resistance and will cause the old style Lucas coil to overheat. Has anyone experienced that?
 
Jimbo
I have a feeling you told your ignition expert a bit more than "real high resistance" and "old style Lucas coil".
Even I would need more than that to make a guess let alone a good guess or an educated guess.
40+ years in high power pulse electronics 15,000 to 60,000 volt and up to 20,000,000 watts peak power, as my basis for a tinker toy hobby for cars and motorcycles ignitions. I certainly don't know them all but can speak to other experts and understand what's going on, if I too have enough info.
Like... what kind of ignition do you have that is overheating the coils? What kind of coils?
dave
 
the NGK irridium plugs are rated 5K resistance the same as a NGK LB05F resisistor cap

Are you running with resistor caps and plugs ?
 
Frankie17 said:
the NGK irridium plugs are rated 5K resistance the same as a NGK LB05F resisistor cap

Are you running with resistor caps and plugs ?
Click to expand...

Plugs, caps AND resistor leads all stack up.
We should choose one resistor type only i.e.
a. wire leads, resistor caps and standard plugs
b. carbon leads, standard caps and standard plugs
c. wire leads, standard caps and resistor plugs
Ta.

PS: if not running any electronics onboard, no resistors is fine but plays havoc with car radios.
 
Slightly off-topic because I don't have standard coils but I do use Denso Iridium 5307 plugs. I have a Power Arc ignition kit which comes with Resistor wires AND Resistor plugs. What works for one person/bike may not work for another.
 
Anglophile said:
Slightly off-topic because I don't have standard coils but I do use Denso Iridium 5307 plugs. I have a Power Arc ignition kit which comes with Resistor wires AND Resistor plugs. What works for one person/bike may not work for another.
Click to expand...

Sounds on-topic if the ignition expert jimbo refers to says that circuit resistance (specifically plug types) causes coil failure.
Ta.
Edification:
http://www.ultralightnews.ca/articles/r ... dplugs.htm
See page 6: SPARK PLUG LEADS http://www.google.com.au/url?sa=t&sourc ... hzV7W_Pqiw
 
needing said:
Anglophile said:
Slightly off-topic because I don't have standard coils but I do use Denso Iridium 5307 plugs. I have a Power Arc ignition kit which comes with Resistor wires AND Resistor plugs. What works for one person/bike may not work for another.
Click to expand...

Sounds on-topic if the ignition expert jimbo refers to says that circuit resistance (specifically plug types) causes coil failure.
Ta.
Edification:
http://www.ultralightnews.ca/articles/r ... dplugs.htm
See page 6: SPARK PLUG LEADS http://www.google.com.au/url?sa=t&sourc ... hzV7W_Pqiw
Click to expand...

The first article is accurate. The second article is not so good.

He says the resistor reduces the voltage at the plug. That is not true. The voltage at the plug is totally determined by the breakdown voltage of the gap. One the spark starts the voltage can no longer rise.
Resistance in the secondary does limit the amount of current flow in the arc and therefore increases the time of the discharge.

Excess resistance can definitely cause problems but not 5000 ohms, 10,000 ohm or even 20,0000 ohms if your ignition system is reasonably healthy. A bit of resistance to increase the duration of the spark can often be a good thing. Jim

PS- I have never heard of a little extra resistance causing a coil to overheat.
 
Hi comnoz.
I agree that the voltage to jump the plug gap won't change wth the various resistor stackup.
However, spark across the gap should be as short, sharp and as powerful as possible to propogate the flame front away and through the air:fuel charge. Having a spark, weaker but sustained for longer, in what is now spent charge around the plug can serve no functional purpose. Resistors exist in the system to protect electronics from RFI but not to enhance spark. I suspect the original poster may have a less than optimal ignition circuit if the coil(s) are overheating so any minimisation of resistance stackup would be beneficial.
Ta.
 
needing said:
Hi comnoz.
I agree that the voltage to jump the plug gap won't change wth the various resistor stackup.
However, spark across the gap should be as short, sharp and as powerful as possible to propogate the flame front away and through the air:fuel charge. Having a spark, weaker but sustained for longer, in what is now spent charge around the plug can serve no functional purpose. Resistors exist in the system to protect electronics from RFI but not to enhance spark. I suspect the original poster may have a less than optimal ignition circuit if the coil(s) are overheating so any minimisation of resistance stackup would be beneficial.
Ta.
Click to expand...

Many of the modern ignition systems tout better performance due to longer spark duration.
The were problems with some of the early CD ignition systems because the spark duration was so short. They never really worked well for 4 strokes until the technology improved enough to increase the duration of the spark.
The use of an extreme duration ignition on my bike has convinced me that spark duration is important although I will agree that resistance is added to stop RFI problems more than anything else. Jim
 
Hi comnoz.
We agree that there needs to be a duration. I simply say just enough duration to ensure flame front (core) and no more.
Ref: Under the heading IGNITION - "...However, if the quenching effect between the electrodes (the work of the electrodes absorbing the heat and extinguishing the flame) is greater than the flame core heat generation action, the flame core is extinguished and the combustion stops...:
http://www.globaldenso.com/en/products/ ... index.html
I suggest the original poster check the coils kV output i.e. its capacity to jump the plug air gap consistently.
A number of conditions affect this capability.
http://www.globaldenso.com/en/products/ ... tions.html
Ta.
 
With the extreme duration high energy spark on my Norton I run 4 degrees less advance than with a conventional high energy ignition. If there is a lot of turbulence in the chamber as there is on a Norton -the long duration spark does help speed the combustion. Jim
 
Hi comnoz.
I suspect your orange does not resemble my apple and we are not resolving jimbo's concern.

Hi jimbo.
I suggest you choose 1 of the 3 resistor options and also assess the kV output of your coils perhaps using the basic equipment shown above or having your ignition expert analyse them with more complex equipment.
Ta.
 
needing said:
Hi comnoz.
I suspect your orange does not resemble my apple and we are not resolving jimbo's concern.

.
Click to expand...

Agreed,

and what is "Ta" ?
Is that like a half a goodby?
 
needing said:
Hi comnoz.
I suspect your orange does not resemble my apple and we are not resolving jimbo's concern.

Hi jimbo.
I suggest you choose 1 of the 3 resistor options and also assess the kV output of your coils perhaps using the basic equipment shown above or having your ignition expert analyse them with more complex equipment.
Ta.
Click to expand...

For christ sake, needing, other than your idiot assed google searches, the simple answer to Jimbo's question is NO, we have not experienced that issue as he mentioned and he should not be too concerned.

Although Jim has tried to explain the advantages of the Norton hemishperical combustion chamber and its relationship to timing and spark, you fail at adding those criteria and your search information becomes incomplete.

Your ungodly ability to uber over complicate a simple question is neither astounding nor amazing and is quite literally useless. Smoke! Give me a break.

Duh.


Duh = needing
 
OK, I threw the question out here because there are a bunch of people here that are very smart. :D Now heres the kicker. The bike is a twin cylinder,water cooled, 1960's two stroke with a distributor , 6 volt coil ignition . Does that upset the apples and oranges cart?
 
needing said:
Hi comnoz.
Simply - Thank you!
Click to expand...

Cool, I guess that isn't something that has made it to the right side up side of the world. That or I'm stuck in my shop too much. :D
 
jimbo said:
OK, I threw the question out here because there are a bunch of people here that are very smart. :D Now heres the kicker. The bike is a twin cylinder,water cooled, 1960's two stroke with a distributor , 6 volt coil ignition . Does that upset the apples and oranges cart?
Click to expand...


No.
 
comnoz said:
needing said:
Hi comnoz.
Simply - Thank you!
Click to expand...

Cool, I guess that isn't something that has made it to the right side up side of the world. That or I'm stuck in my shop too much. :D
Click to expand...

Ta is colloquial English English for thanks Jim, just as needing says.

I use it/hear it in conversation....and have done for decades....though I probably got it from my time living towards the North of England....not the South where I originate and now live.

Ta Ta is as you indicate what we teach our children to say for goodbye.
 
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