Spark Plugs

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What spark plugs are some of you currently running ? Single or multi tip ? My newly rebuilt 1500 has 10.5 comp with Matts performance head (shaved) Thanks,

Bob
 
I used to use Champion N9Y plugs but for my new engine I got NGK BP6ES plugs based on what I have read here. If I wasn't using using helically wound wires for RF suppression, I'd go with the BPR6ES.
 
Just for reference I have found that any plug in the proper heat range works fine. But plug wires, now that is where it is at. Taylor Spiro Pro for me.
 
Don says: used to use Champion N9Y plugs but for my new engine I got NGK BP6ES plugs based on what I have read here. If I wasn't using using helically wound wires for RF suppression, I'd go with the BPR6ES.

i have to buy a new set of s.p., (i use helically wire leads), wich plugs i should buy? i currently run a set of bosch WR7DP that are really white for overheathing (probably due incorrect inition timing), all the manual that i found says to trash the plugs if they are so white

last year i purchased the bosch platinums because found a text on the wiki xweb section that says they add 3hp (!!) i didnt belived that but thought anyway they are good sparkplugs
 
Don says: used to use Champion N9Y plugs but for my new engine I got NGK BP6ES plugs based on what I have read here. If I wasn't using using helically wound wires for RF suppression, I'd go with the BPR6ES.

i have to buy a new set of s.p., (i use helically wire leads), wich plugs i should buy? i currently run a set of bosch WR7DP that are really white for overheathing (probably due incorrect inition timing), all the manual that i found says to trash the plugs if they are so white

last year i purchased the bosch platinums because found a text on the wiki xweb section that says they add 3hp (!!) i didnt belived that but thought anyway they are good sparkplugs
If you are using helically wound wires you should be able to get by without resistor plugs and still be able to get decent AM radio reception. Resistor plugs, resistor wires, or helically wound wires are all designed to increase the rise time of the spark waveform. This reduces harmonic emissions in the radio spectrum. You should not need to use more than one of those solutions together, and if you don't listen to AM radio, you probably don't need any of them. In terms of performance, the helically wound wires have much less of an effect on spark amplitude than the resistor solutions but if your ignition system is in good shape, I'm not sure you would notice a huge difference between them.
 
Back in the 70's I participated in a SAE certification program. One of the instructors prided himself as being very scholarly, highly experienced, and on the cutting edge of automotive technology. He insisted the greater the amount of resistance built into the secondary spark system (high side), the greater the spark will be at the plug tip. Something about Ohm's Law and how overcoming resistance increases the potential. So his theory was to use resistor wires, resistor plugs, and a cap / rotor made with high resistance material (can't recall what that was). But then again, he also purchased a new Corvette and sealed it up to hold onto until it became worth a million dollars. Wonder if he is still hiding that car and waiting for it to appreciate? And if his daily driver starts on a cold morning?
 
Back in the 70's I participated in a SAE certification program. One of the instructors prided himself as being very scholarly, highly experienced, and on the cutting edge of automotive technology. He insisted the greater the amount of resistance built into the secondary spark system (high side), the greater the spark will be at the plug tip. Something about Ohm's Law and how overcoming resistance increases the potential. So his theory was to use resistor wires, resistor plugs, and a cap / rotor made with high resistance material (can't recall what that was). But then again, he also purchased a new Corvette and sealed it up to hold onto until it became worth a million dollars. Wonder if he is still hiding that car and waiting for it to appreciate? And if his daily driver starts on a cold morning?
I guess he forgot that Ohm's Law can also be written as I = V/R so the spark discharge current is going in the wrong direction as R goes up. Did he do one of those deals where they put the car in a big bag and fill it with nitrogen? Hopefully, he remembered to drain the gas tank.
 
He was a bit of a character. A lot of his theories were just as suspect; things like one particular brand of spark plug creating a big power gain, or the use of a particular can of oil additive making your engine last forever, etc. None of which generated much confidence in his qualification as a tech instructor (at least not to me). Seemed like a ex-military type personality. But he was able to bring in some outstanding individuals from various sources as guest lecturers, with great material. I have no idea what he actually did with the Vette, he just liked to talk about it. He seemed convinced it would become a rare collectable car because it was the first year of a new body style generation (this was in the late 70's).
 
I hesitate to get into the whole "spark plug" discussion too much. But with regard to Iridium plugs I will relate a prior experience.

Back when I was active with 2-stroke dirt bikes it was vital to find the right plug. First those engines run rather hot, second they had a very basic induction system (extremely simple design of carb), third the ignition was even more basic with a straight timed spark, forth they use a oil/fuel mixture to lubricate the internals (which means the combustion was of a oily fuel), and last they were highly abused. So you have the perfect formula for detonation if the plug is slightly too hot, fouling if it is slightly too cold, and poor running if it isn't "just right" with not a lot of "tuning" available to compensate for things.

The common plug choice for dirt bikes in those days was NGK. For the most part they were standard type plugs, with a "racing" (thinner electrode) version available for a premium price. One thing I found with NGK was a very limited selection of heat ranges. If you look at a cross reference chart with most any other plug brand, you will see each NGK plug has to cover the heat range of 3 to 5 plugs from the others. That made it difficult to get a NGK in the right 'window', especially when the engine was modified and running on the edge. Even with the 'racing plug' I'd go through one every time I went out, and at the price of them it wasn't economical.

However back then many of the other plug makers were not too active in the "powersports" market so they did not list much for 2-stroke applications. I experimented with plugs from Champion, Bosch, AutoLite, and others. About that same time Bosch introduced the Iridium plug with the thin wire electrodes. I found that design worked far better than any of the others with a more standard design. Something about the electrodes being a skinny round wire and the Iridium material allowed the plug to run clean without detonation. I believe another advantage to the Iridium plugs (in addition to a longer life) is it allows for a finer electrode design.

Obviously that is not a direct comparison to our SOHC Fiat engines. And since then there have been many developments to plug technology, including other materials used for electrodes. But I still find the double Iridium fine wire (for both electrodes) plugs work very well for my vehicles. And now most of the plug manufacturers offer that choice. I recently found some on sale with a rebate that made the final price about $2 a plug. But I won't go so far as to say they are a "better plug", only that I've found them to be quite satisfactory for my needs.
 
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Plugs and oil are all personal preference, so asking what works or what's best is sorta asking which is better blondes or burnettes. Which then someone will inevitably pop up with I prefer redheads. It's an exercise in spinning your wheels. My personal opinion is:

For plugs:
Find ones that fit and use those.
For oil:
Use whatever stuff that you end up buying.

This really isn't as complicated or world ending, that too many may have you think.
Unless your racing your car at a competitive level with insane compression or where thousands of a second matter, or you have some very trick and exotic custom built engine; any spark plugs that sparks, is all you need. Same with oil. Keep in mind these motors were designed in a time where there were like 3 spark plugs and oil options here in the states, and that's it! (being facetious, but you get the idea)

I like coppers and 10w30 but it's irrelevant.
 
I only use Bosch WR7DC copper plugs, but mine is FI, and Wasted Spark ignition. Never had luck with NGK, very short life for me, plus you have to remember the heat range is out of whack compared to Bosch. Platinum's don't work in my current setup). I have used Bosch in everything (FR7MPP10 in the C30), but will use Japanese plugs in the Honda motor. :D
 
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I have used Bosch single electrode platinum since the late 80's in FI x's. No issues.

As for NGK Iridium, I tried those in my old 5cyl 20v turbo Audi. Burned the tips completely off the plugs in 11k miles. Went back to Bosch Copper 3 electrode and had no issues.
 
As for NGK Iridium, I tried those in my old 5cyl 20v turbo Audi. Burned the tips completely off the plugs in 11k miles.
That might have been a consequence of what I said earlier; NGK offers a very limited heat range selection for each application. Their entire line of plugs is significantly less than that of other plug makers. So the plugs recommended for any given application may be off by as much as 3 or 4 heat ranges (compared to what the others offer). Therefore the ones you had might have been too hot, and the electrodes burned off. To further complicate this problem, if you went to one size colder NGK plug it might have been way too cold and fouled. They just don't offer enough of a heat range selection to work in many cases. I'm not bashing NGK, just relating what I've found in my experiences; in my opinion sometimes it does matter what brand you choose.
 
I have had great luck with the E3 plugs.

Hopefully Andrew Kimball will chime in. I think he was using the NGK Iridiums and they did not work for him. This was the first time I had seen the problem but the plugs would fire on the first rotation or two of the points distributor then the spark would bleed out and then no spark. At the time we did not figure out why (he may have since then) but he changed plugs and the engine fired up like expected.

 
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