I remember starting a thread a long time ago here trying to get some input on how to standardize and quantify plug effectiveness. Guess it might have been helpful if we had come up with something. But I recall the thread falling off because trying to decide how to deal with all the variables being too much.
That said, I am into plugs probably as much as you are and I would definitely be willing to collaborate with coming up with some sort of test methodology. As far as I know there is no ASTM or ISO standardized testing for plugs so we would be pioneering new ground in a way if we did. So if you want to work on it, I am more than willing. I personally think it would be a good collaboration actually.
With that a few things that come to mind:
1. Ease of spark - Does one spark plug fire easier, over come the gap better than another, minimum voltage needed to spark (not sure how to test for this)
2. What are the internal resistances of the plugs - Measure with a multi-meter
3. What kind of configuration is the plug - Surface gap, Sidegapped, Conventional, etc.
4. Idle improvements - Again, not sure how to measure this, I have some ideas though.
5. Fuel Economy - Easy enough to measure, just have to standardize the way the tank is filled up. I wrote an article on this once and the ways you can measure fuel economy, so I got that covered.
6. Acceleration - Several variables here, but if we could come up with a few testing standards, it would at least give a general overview.
7. Quality - How well is the plug made.
8. Materials - What is the plug made of
If you are serious and want to try it, I would be more than willing to work on it and see if we can come up with something. We could even try and build a test stand (basically a power source, coil and plug) and fire plugs that way. The fact is that there will always be unaccounted for variables no matter what we come up with. However, if we just take a stand and start somewhere, we can come up with something and then improve it as we collect data.
Definitely potential here.
1. Easy of spark - I'm with you here, not sure how to test this especially in a DD engine.
2. Resistance - I have a Fluke 77 and an oscilloscope.
3. configuration - easy enough, although I'm not sure how to classify the LGS configuration.
4. Idle - On a car with an XP cam, that would be tough, Although a before and after scan would be all that I could come up with.
5. Fuel Economy - I drive the same 60 miles everyday so no big deal. Although perhaps not accurate, wouldn't just going by the DIC at least be consistant? Mine seems to be as long as I intentenionally maintain a give MPH.
6. Accelleration - I'm not sure on this one. A dyno would be a good way, but not in my budget nor something I want to put my car through.
7. Quality - somewhat subjective, but none the less a needed item.
8. Materials. usually we only know information about the center electrode. In plugs like the Autolites, we know the "core" is copper, however we don't know what the coating exposed to the spark is made of. Brisk Silver racing plugs are solid silver...Trannyman, have any pictures handy?:th_lipssealed1: Some of this info will only be what is published by the maker. As this is the case we will have to be careful not to call things like copper core, copper...ect.
I can get some resistance reading, on AL 605, 104, NGK TR6IX, Nology Silver Racing, and Brisk LGS plugs pretty quick.
One thing to note is that since our ignition module has a current limiting circuit, resistance or lack of, may actually have little to no effect. Still know the resistance would be interesting, although impedance moreso.
