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View Full Version : FACT OR FICTION: Platinum Spark Plugs don't need to be gap



liplip
05-15-2007, 06:53 PM
Is it true that platinum spark plugs are already gapped for the specific car?

Azzazzyn
05-15-2007, 06:57 PM
my car comes with platinums, and i have a little sticker thing that says no gapping required

liplip
05-15-2007, 07:01 PM
I'm confused because the guy at the parts store says that even mechanics don't gap platinum plugs yet when i looked at the packaging it says "IMPORTANT: gap to the manufacturer's setting of the car".

davmac
05-15-2007, 07:19 PM
Most of the spark plugs you buy are pre gapped. You can still check the gap. I'd be surprised to find one out of adjustment, but it happens. Just be sure to adjust gap gently using the ground strap only. Platinum and Iridium sparks recommend no adjustment because the fine tip of the electrode can be damaged. Just don't adjust gap by prying the ground strap with something between the electrode and ground strap.

Azzazzyn
05-15-2007, 07:24 PM
i just get mine from nissan....so.....

T-spoon
05-15-2007, 09:12 PM
Yeah, from the dealership plugs are pre-gapped, you don't touch'm, though checking the gap, as was said, is not a bad thing to do. I wouldn't go by the idea that a particular kind of plug is always gapped because who knows, some manufacturers might not, as far as Toyota goes, if it's OEM from the dealer, it's gapped.

Luis C
05-16-2007, 01:38 AM
Check and adjust if neccesary, 50% of the time mine are off

Luni
05-16-2007, 01:45 AM
Dont ever try and gap an iridium. Dont do it.

PhillyDRFT
05-16-2007, 02:16 AM
I always use NGK V-powers. I check the gap on them every time and I've never gotten a bad one. What are you guys using?

I've never herd anything about platinums in particular not having to be gapped, but like has alredy been mentioned. Most come pre gapped. They didn't before but lots of idiots would just throw them in without checking and then say "This brand is shitty, They made me misfire like crazy. Bought some from the dealer and didn't have a single problem" Taking the end user out of the equation always helps.

Rix86
05-16-2007, 03:05 AM
you run the chance of damaging the platinum electrode.

InitialD93
05-16-2007, 03:19 AM
iridiums and plugs with multiple straps (like Bosch +2 or +4) are the only plugs that are NOT gapped... all other plugs CAN be gapped and should be checked before install... my AC Delco plugs i just put in the Malibu were off up to .15 suggested gap.... always check ur gap if they are gappable plugs

Luis C
05-16-2007, 03:49 AM
My Denso Iridiums never came correctly gapped , they are way off by a bunch. I have to gap them but be ubber carefull

MoralWarfare
05-16-2007, 04:49 AM
I never check, maybe I should get a gauge sometime. I always freakin lose them within a day of buying them.

alltracman78
05-16-2007, 05:19 AM
I always end up regapping my irridiums.....

You just have to be careful.

grayscale
05-16-2007, 11:16 AM
Luni is right here. The nature of Iridium spark plugs means that they are able to utilise a larger gap setting while actually requiring less voltage and straining the ignition system less. If you *have* to regap Iridium spark plugs if misfire occurs due to the gap being too large then do so with extreme care.

PhillyDRFT
05-16-2007, 06:11 PM
So heres the best question, What gauge do you all use to measure your gaps? The little wheel thing from auto zone or a real gap tester and a pair of needle nose pliers?

InitialD93
05-16-2007, 07:19 PM
feeler guages FTW

but the autozone thing is usuallt within .05 of correctness so in a pinch u can make it work

liplip
05-16-2007, 07:26 PM
What is the correct gap for 1990 celica gt?

InitialD93
05-16-2007, 07:54 PM
.043"

celica9303
05-16-2007, 09:07 PM
I always use NGK V-powers. I check the gap on them every time and I've never gotten a bad one. What are you guys using?

I've never herd anything about platinums in particular not having to be gapped, but like has alredy been mentioned. Most come pre gapped. They didn't before but lots of idiots would just throw them in without checking and then say "This brand is shitty, They made me misfire like crazy. Bought some from the dealer and didn't have a single problem" Taking the end user out of the equation always helps.

FYI the v-powers (bkr6e-11) are not platinum plugs they are copper. the correct plaltnium plug for ngk is bkr6ep-11 they are about 7.99 a piece.

alltracman78
05-17-2007, 01:49 AM
Luni is right here. The nature of Iridium spark plugs means that they are able to utilise a larger gap setting while actually requiring less voltage and straining the ignition system less. If you *have* to regap Iridium spark plugs if misfire occurs due to the gap being too large then do so with extreme care.

How exactly do they conduct better than copper?

I use them because the tip is MUCH thinner and tends to take longer to foul out.

I was referring to gapping out of the box. I always check mine and they're usually off.

Luni
05-17-2007, 01:56 AM
Jeremy, how do you gap them?

Its my understanding, you run the risk of damaging the electrode, and then the thing breaks under extreme heat and boost, and you got a piece of hardened iridium bouncing around in your combustion chamber scoring the fuck out of your cylinder head.

Im told if you ARE going to gap them, use a pair of sensitive needle noses with electrical tape wrapped around the tips so as not to damage the plug itself.

Its just really hard to gap them cause the center piece is like needle thin and measurements against it are hard to get accurate.

liplip
05-17-2007, 01:58 AM
I checked the gap of the platinum spark plugs out of the package and they're not gapped correctly.I guess that answered my question.This is the first time i've ever changed the plugs since i'm just learning the "how to" of cars.I drove the car after changing the plugs and there is a noticeable difference in the reaction....no more hesitation or bogging.

alltracman78
05-24-2007, 03:47 AM
Jeremy, how do you gap them?

Its my understanding, you run the risk of damaging the electrode, and then the thing breaks under extreme heat and boost, and you got a piece of hardened iridium bouncing around in your combustion chamber scoring the fuck out of your cylinder head.

Im told if you ARE going to gap them, use a pair of sensitive needle noses with electrical tape wrapped around the tips so as not to damage the plug itself.

Its just really hard to gap them cause the center piece is like needle thin and measurements against it are hard to get accurate.

1-I don't gap used plugs.

2-I don't use needle nose pliers [either too thick or if thin enough they tend to twist instead of bend the ground].

3-I use either a little tool on the end of my gap gauges [I'll TRY to remember to get a pic when I'm at work] or I GENTLY tap the ground on a secure metal table, frequently checking gap until it's right.

celicaGT90_05
05-24-2007, 03:59 AM
to gap a plug you buy this little ring (like $0.75) from autozone or advance and you put it on the bottom and work the plug up to wherever you need to gap it to. Plugs now-a-days are coming pregapped, but it never hurts to double check

alltracman78
05-24-2007, 04:10 AM
It depends what you're buying it for...

Especially if it's not the stock plug you can't automatically trust the gap.

And I believe the gapping question isn't how to measure the gap but how to safely change it.

Dr.Auto
05-24-2007, 04:27 AM
I am totally with Alltracman here..........

Always check plugs........ Now remember there is a correct way and an incorrect way. Most people use the incorrect way.

If you ever adjust gap on a plug and you are touching the electrode in any way shape or form you are adjusting it incorrectly. All adjustment is done on the ground strap.......which is not Platinum or Iridium even though the plug may be. If you use a proper gap gauge you will be ok. They typically have a part made into them that will grab the ground strap without touching the electrode and gap adjustment is very easy. You just have to be very very very very carful when actually measuring the gap........no pressure on the electrode. You don't use typical "feeler guage feel" way of checking it.

I learned the hard way............ just because they are spark plugs does not make them exempt from being droped, damaged, tossed on a counter, or treaded in a way that would possibly impact the ground strap in some way to bend. I have had a hand full of brand new plugs right out of the box that were gapped to .000" AC Delco is the worst for this because they spiratically use the little protector sheiths that go around the end of the plug. Don't piss off parts guys......... I've seen they pissed at certain techs (not me) and slap the box down on end on teh counter top on purpose....... the intention to make the gap .000"

Quote:
Originally Posted by grayscale
Luni is right here. The nature of Iridium spark plugs means that they are able to utilise a larger gap setting while actually requiring less voltage and straining the ignition system less. If you *have* to regap Iridium spark plugs if misfire occurs due to the gap being too large then do so with extreme care. "

Luni is correct in saying not to screw around with Iridium plugs...... becasue most people will mess them up so leave well enough alone.

But Platinum is a better conductor than Iridium. And copper is a better conductor than platinum. And gold is a even better conductor of electricity. But as we get better and better with being conductive we also get softer and softer with our metal ... and in spark plug usage means a shorter life span. The metal used has an effect on firing voltage in the reverse of what you mentioned.... a Copper plug at a .045" gap will require the least amount of firing voltage compared to a platinum with a .045" gap. And the Iridium will require the most at trhe same gap. The actual gap is the biggest factor of what the firing voltage will be. The wider teh gap the higher the firing voltage will be. Cylinder pressures and fuel ratios along with atomization of the ratio all factor in along with VE....
But plain and simple. The Iridium gapped at .045" in a 91 celica is going to require serious firing voltage and will strain the ignition system more than needed to give a good spark. The spark will be awsome but thats only because of the drastic firing voltage needed to jump the gap......... its only so long till you damage the ignition system. The same application but with a copper plug gapped at the same .045" will have a much lower firing voltage but will be much less stressfull on the ignition system....the weak point then being the spark plug just as the manufacturer desighned........ and thats why you replace the plugs every 30k. But with the Iridium.......... Yes teh spark plug will last longer...... and have a "hotter" spark (higher firing voltage). But at teh cost of potentially frying the entire ignition system before the iridium plug is ready for replacement. Unless you upgrade teh rest of teh ignition system accordingly to offset this problem.

**the MAIN point of the statment I had a problem with **
Quote:
Originally Posted by grayscale
"The nature of Iridium spark plugs means that they are able to utilise a larger gap setting while actually requiring less voltage and straining the ignition system less. "

That right there is totally false............that statment totally defies all of the basics of physics. The Iridium plug will require much more voltage to fire and stress the ignition system as a result of running at a higher voltage than origionally desighned to do.

celicaGT90_05
05-24-2007, 04:42 AM
It depends what you're buying it for...

Especially if it's not the stock plug you can't automatically trust the gap.

And I believe the gapping question isn't how to measure the gap but how to safely change it.

exactly, while they are tryin to make them so you dont have to gap them, it never hurts to check....but most people wouldnt

extremeskillz
05-24-2007, 01:37 PM
They are pregapped. The reason the package says that is because of just in case the gapping mysteriously is off on the plug. Very rare but if you do what i do is double check the gapping anyways just in case.

extremeskillz
05-24-2007, 01:37 PM
o the gapper itself is very cheap and very useful tool for other maintenace projects you have (lawn mower, etc). And cheap insurance.

grayscale
05-24-2007, 03:00 PM
I am totally with Alltracman here..........

Always check plugs........ Now remember there is a correct way and an incorrect way. Most people use the incorrect way.

:blahblah: :blahblah:

**the MAIN point of the statment I had a problem with **
Quote:
Originally Posted by grayscale
"The nature of Iridium spark plugs means that they are able to utilise a larger gap setting while actually requiring less voltage and straining the ignition system less. "

That right there is totally false............that statment totally defies all of the basics of physics. The Iridium plug will require much more voltage to fire and stress the ignition system as a result of running at a higher voltage than origionally desighned to do.
I understand your thinking but in this case the path of logic is incorrect. The difference in firing voltage between the three plugs you mention is not so much the material as it is the size of the electrode. A spark jumps more easily between small, sharp surfaces than large dull ones - which is the reason why iridium plugs require less firing voltage. I NEVER said iridium conducts better than copper, that's what Jeremy thought I said. The main reason for using iridium electrodes is to minimize electrode wear. Every time a plug fires, a tiny amount of metal is vaporized and lost from the surface of both electrodes. The center electrode typically suffers the most wear because it runs hotter than the side electrode. As the electrodes wear, the air gap across which the spark must jump becomes wider and wider. The gap on a standard spark plug grows about 0.00063m. to 0.000126 in. for every 1,000 miles of normal driving. And the wider the gap, the greater the voltage needed to jump the gap. On standard plugs, the firing voltage requirements creep up about 500 volts for every 10,000 to 15,000 miles of driving. Eventually, the plug may need more volts to fire than the coil can produce, causing the plug to misfire.
However, the performance reasoning behind iridium is that the smaller tip (able to be used because of it's density) can centralize and create a more intense and stable flame kernel than conventional plugs. But because of the smaller tip and and more intensely focused arc, iridium plugs can utilize a larger gap with less energy than other plugs while still maintaining a strong arc. Standard plugs with too large of a gap= a weak arc which= misfire. What the manufacturers are trying to tell people is that iridium plugs ARE NOT GAPPED THE SAME AS STANDARD PLUGS, the preset gap is BECAUSE they are iriduium, not because they are gapped to manufacturer specs.

One thing to keep in mind about all "performance" spark plug designs is that no plug can magically create horsepower out of thin air or add horsepower that wasn't there in the first place. But improved ignition reliability can minimize horsepower losses caused by misfires. That's why some plug manufacturers claim their spark plugs improve power. The gains come from power that was being lost to misfires.

Also, I do know that each material has it's own conductive properties and one is better than the next, however, I have yet to see any info on the cunductive properties of iridium, everything I have seen so far is from manufacturers and retailers which is not what I'd call reliable. If anyone has some info or comparisons on the materials in question I'd like to see it, iridium material itself is actually still a mystery to me.

But, all in all, for most people, i.e. daily drivers and street modders, the idea behind iridium is that they last longer than anything else. The same reason platinum was introduced in 1982. The only reason they caught the attention of high performance crowds is that if they last longer than they must be able to take more abuse right? So from there they find iridium has more value than just durabillity.

Here is a story from the Denso site. As I mentioned, I try not to rely on manufacturer info when possible as it is usually a little 'skewed', however Denso has provided contact info for this article if you want to call the guy himself.
Resource-
Leonard Emanuelson / autoMedia.com
(Original article- http://www.automedia.com/Iridium/Spark/Plugs/pht20010101ds/1)

Denso, www.denso.co.jp/index-e.html

Kenny Duttweiler contact- Duttweiler Performance, 1563 Los Angeles Ave., Saticoy, CA 93004, (805) 659-3648

"Iridium Spark Plugs-
New iridium spark plugs fire where conventional platinum plugs fail

Spark plugs get no respect! In fact, a lot of performance enthusiasts don't give them a second thought. They spend thousands of dollars building the ultimate performance engine then simply screw in whatever plugs the local auto parts store has in stock. The perception is that spark plugs are the lowest-tech components in the modern internal-combustion engine.

Change is Good
It's no wonder. Contemporary electronic ignition systems have made spark plug replacement in everyday passenger vehicles a thing of the past. And when a racer or high-performance engine builder has a misfire problem, the first thing he does is to add a more powerful ignition system. That's about to change. When the word gets out about the new Denso Iridium Power spark plugs that added 750-hp to Kenny Duttweiler's 450-cid twin-turbocharged Ford, engine builders and tuners will gain more respect for the lowly spark plug.

Kenny Duttweiler of Duttweiler Performance in Saticoy, California is no stranger to making horsepower, especially with turbochargers. After years of building little turbocharged V-6 Buicks that produce in excess of 1,500-hp, he found a lucrative market in NMCA's "World Fastest Street Car" classes building 1,700-hp small-block Chevy V-8s for winning racers such as Bob Rieger and Rod Saboury.

So when he bolted a customer's NHRA AA/Altered Turbo Ford engine on the dyno and had problems making the requisite 1,950-hp (out of 450 cubic inches on gasoline), he left no stone unturned. The engine had state-of-the-art everything—Motech engine management system, MSD Digital 7 ignition system and everything else you could think of. Kenny had isolated the problem to inadequate ignition performance. There was no audible misfire, but the engine made 1,700-hp at 17-psi of turbo boost and only 1,100-hp at 24-psi, indicating that the increased cylinder pressure was causing an undetected intermittent misfire. Reasoning that it was an engine-management or ignition-system problem, he replaced both. However, his Stuska dyno yielded the same results. Kenny replaced spark plugs several times with the best racing and platinum plugs he could find; still no improvement.

Kenny had correctly diagnosed the problem, but as far as he knew, there was no solution. He was already using the most powerful engine management and ignition systems on the planet, and he'd tried most of the "state of the art" spark plugs on the market. Kenny was running out of options and stated prophetically, "Some engines are spark-plug sensitive, especially Hemi-style engines. That's why Chrysler designed dual-plug cylinder heads for their Pro Stock motors in the early '70s. A turbocharged race engine is a variable-compression engine. At 25-30 psi of boost, the cylinder reaches an incredible 2,800-3,000 psi. The higher the cylinder pressure, the harder it is to fire the spark plug. This Ford engine we're developing is the worst of all circumstances. It has a hemispherical-shaped combustion chamber and a 4.670 cylinder bore that is a large area to light off at high rpm."

Kenny had no idea that the solution to this perplexing problem would be a new iridium spark plug technology from Denso. In Denso's research for an OEM spark plug that would provide 200,000 miles of service life and lower vehicle emissions, Denso developed a new iridium alloy electrode spark plug. The progression from nickel alloy plugs to platinum plugs in 1982 was a giant leap forward in technology. Denso's introduction of the iridium alloy spark plug will prove to be even more significant, especially for high-performance and race engines. The major difference in the Denso Iridium Power spark plug and conventional platinum plugs, besides the alloy, is the size of the center electrode. A typical platinum plug has a 1.1mm diameter center electrode. The Denso Iridium Power OEM plugs have a .7mm diameter center electrode and the Denso high-performance plugs have a .4mm center electrode.

Size Matters
What does size have to do with it? Less voltage is required for a smaller center electrode and results in better ignitability. The smaller the electrode, the more centralized the electrical potential is around the electrode tip. The required voltage can be reduced because the level of the electric field is made stronger and local insulation (air gap and electrode surface oxidation) breaks down more easily. The bottom line is that it takes approximately 5,000 volts less to fire a Denso Iridium Power spark plug versus a conventional platinum spark plug.

So why not just make a smaller diameter electrode spark plug out of platinum? It just wouldn't last. The small-diameter center electrode reaches much higher temperatures. Iridium's melting point is 700 degrees C higher than platinum, and laboratory tests have shown that with the same-size electrode iridium, plugs were four to five times as resistant to wear as platinum. Much of Denso's R&D went into finding the perfect iridium alloy (90% iridium, 10% rhodium) that would provide 200,000 miles of service, and working out the manufacturing process to "draw" the electrode into the extremely small .4mm-diameter wire.

The Test
Kenny was contacted by a Denso representative to test a set of Denso Iridium Power high-performance spark plugs under extreme, real-world conditions. So he installed the plugs and ran the turbo boost all the way up to the 40 psi limit. The dyno numbers tell the story: 1,850 repeatable horsepower, test after test. Kenny admits he's still shy 100-hp from the goal of 1,950-hp, but a camshaft change is in the works to make up the deficit.

grayscale
05-24-2007, 03:06 PM
Is it true that platinum spark plugs are already gapped for the specific car?
But as to your original question, sorry we got so far off here, it's just as everyone has said- they gap them at the factory for what they are made for but should be checked just in case:bigthumbu

celicaGT90_05
05-24-2007, 04:57 PM
^^

That's been said about 5 or so times now lol

Dr.Auto
05-24-2007, 07:29 PM
One thing to keep in mind about all "performance" spark plug designs is that no plug can magically create horsepower out of thin air or add horsepower that wasn't there in the first place. But improved ignition reliability can minimize horsepower losses caused by misfires. That's why some plug manufacturers claim their spark plugs improve power. The gains come from power that was being lost to misfires.

I love the way you worded this. This is the best I've seen this presented with teh least amount of words.

As far as the argument of what plugs to use and what the firing voltages are......... we would really have to get specific to application, plug type, gap, ignition system, compression/combustion pressures and fuel ratio/atomization to really see what happens. Nothing can argue with a scope actually measuring the firing voltage on car.
Your clarification makes tons of sense. Having a smaller electrode diamter.........makes sense....... but I would be curious to see how much it really reduces firing voltage. Current takes the path of least resistance.......and we also have air gap resistance to consider with this application. Even on a larger diameter electrode copper plug the spark is not going to include the whole tip of teh electrode but typically the edge, or just a spiratic part of it as it wears like you mentioned finding the little spot on the plug thats the shortest path to ground. The spark size (in diameter) will grow with increased voltage..... not being effected by the real shape of teh electrodes because the spark is just simply taking the shortest path to ground any way it can find it. Now a smaller diameter electrode I can see making this more consistant........putting the spark where you want it in the spark plug. But whatever....... I'm no spark plug engineer........and alot can change from the exact same plug but in a differant engine/application.

The point is to have consistant spark throughout the life of the spark plugs without needing to over exert or need more power than what the ignition system is capable of and that is when current still takes the path of least resistnace.....even if its through the casing of teh coil and going into self destruct mode. Thats really all that matters.