Obviously, millions of do-dads were made to "improve" the performance of Lizzy. Several companies made dual electrode plugs, such as this one.... http://www.flickr.com/photos/bruckzone/8089334337/in/set-72157631228119782
Here are my questions:
1. What gap? if .025 is good (i.e. the champ x), would we want both side electrodes that far from the center, or the total of both gaps to be .025?
2. Since the spark will jump to the closest point the gaps would have to be set EXACTLY equal no?
3. If the double spark is achieved but the total gap jumped is greater than the standard single electrode, what would be the effect on the coils life/performance.
4. Lastly, what would be the possible performance improvement?
Link to a video of a dual electrode X plug I made just for kicks being tested on a HCCT.
http://www.flickr.com/photos/bruckzone/8089358868/in/set-72157631228119782
There will be no performance improvement. Only one electrode can fire at a time because one will be closer than the other until it wears some, then the other will be closer until it wears some, and so on.
You should gap it as you would any plug for a Model T.
Again, a double spark will not happen.
Erich-
I was going to say that you have to have your coils set just right to "double spark" to get a double spark from a double electrode spark plug...
...but then someone might believe me, so I'll keep my smart alec comments to myself!
Cool looking plugs.
: ^ )
Keith
Haaa Keith, I hadn't thought of that.
I can get the electrodes set to get a double spark in the open, but what would happen in the combustion chamber, or after a short wear period? Who knows. Royce probably nailed it.
These must have been like the fishing lures that don't catch fish but were only designed to catch the eye of fisherman in the store; mission accomplished.
The only lingering question in my mind is based on the performance improvement I noted upon switching to a dual prong plug once in my old honda C-70 (low power to weight, like lizzy). But that may have had nothing to do with the dual electrode feature.
Keith, now that is funny!
Seems to me the closest electrode would spark until it wore even with the other one. From then on, it might be a crapshoot. Getting both to fire at the same time could be iffy. If the sparks were far enough apart physically, then there is advantage, like with two plugs in the same cyl.
Then there is the shading phenomenon, which inspires some to index their plugs, and has been discussed here....
rdr
I think multiple electrode plugs are in the same category as those carburetor accessories that are supposed to "swirl" the intake to improve performance: bo-o-o-o-o-o-gus.
I've had some real nice dual electrode spark plugs over the years and when they didn't work as well as others I ground off one electrode.
Problem solved.
My sisters car specified plugs with 4 electrodes and they did make the car go a better and use less fuel. i set a plug like that with equal gaps and they sparked exactly one prong then the other.
it has to do with ions or something, im not sure how it works, but somhow it lowers decreases the amount of times one gap has to spark thus creating a hotter spark each time.
you arent supposed to get a double spark, but an alternating spark like Kep says.
Seems many of the new cars are rated to go 100,000 miles without major tune up. Perhaps the 4 prongs let them wear that long while a single prong would never make it that far?
Even though I am sure it is 99% snake oil, I may try a seat of the pants experiment and run a set of these, in the interest of science.
I have several sets of NOS Gambles plugs with dual electrodes. I have watched them fire in my plug cleaner and they spark one and then the other or maybe both. They run very well and I ran a set of them in my last speedster and in my last Mt 500 car. Whether that is because of the dual electrodes or just because they are good quality plugs, I dunno.
Erich - Only 100,000 miles without a major tuneup?
I must be doing something wrong!
My wife's Dodge Grand Caravan (bought new in 2006) has 190,000 miles on it and we have never changed the plugs or wires.
Every time I mention the possible need for a tuneup my mechanic he asks me if it runs rough or if the gas mileage has gone down.
When I say no he says, "I don't think you need to anything just now."
Fred, according to Click & Clack, the tappet brothers, there is a danger of the plugs being very hard to remove after being in there that long (so it must be true). But, if it aint broke......
Stan, I am curious enough to try it, so will report back at a future time. Any photo of those Gambles plugs?
The EPA requires all new cars to go a minimum of 100,000 miles and still meet new car emission standards. This is why new cars have extremely high voltage ignitions and single electrode heavy metal plugs that can withstand the welding arc level current / voltage for that length of time.
My boss drives a 2001 Ford F150 with 400,000 miles on the original 4.6 engine, including the plugs, coils etc. It just passed an emission test.
How about this one, a Flame Spinning Electrode Spark Plug?
ebay listing
Funny the last post is a photo of a Fan Flame.I bet that thing would be interesting to watch as it worked.I had seen 1 years ago.Thought I actually bought it but it was another 1 I bought.I have a couple 4 prong T plugs.I think 1 is a American Bosch with the race car drivers head on the porcilen.
That fan flame covers 2 issues as it offers poly-spark as well as swirling action. Hope it isn'nt rotating counter to the swirler on the intake, unless that would be good.......don't slip in the snake oil.....
I'd like to try that out in my Champion spark plug tester. It has a viewing window so you can watch the spark under pressure. But without the air flow of a real engine, it wouldn't be as exciting.
When they are both gaped the same and getting the same spark at the same time then what is happening is that there is a larger spark and more of the fuel is ignited. Regardless of the car and the plugs there is still an amount of fuel that just goes out the tail pipe so to have more fire then less fuel goes out the pipe.
I remember reading something concerning temperature causing the spark to occur at a second (or third, whatever) electrode. They don't all spark at the same time however.
Actually there is never a spark on both electrodes because, try as you may, one is always closer to the ground than the other. That's why any time someone says there is a simultaneous double spark and it will increase performance you know for certain that person is mistaken or lying.
Although not for 'Ol Jezz, kind of weird. Mics up at about 17.5 mm At first I thought old Maytag, but not with the straight threads?? troop
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Well here are 3 of my weird plugs.My American Bosch,a Stewart Vray and a odd ball.
Try setting the gap on the middle 1!
Not only the distance between the electrodes, but such things as minute differences in air flow, pressure, carbon buildup, ionization, all affect which path will fire. All these variations only need to be off a tiny amount, at the atomic level. The spark will always find the path of least resistance. It could actually fire on two paths at the same time. Probably about one time out of a million.
I still really liked the Edison dual fire plugs I used to have. They ran great. I have not yet found the matches for the couple I have left.
The modern F-11 is for size comparison.
Drive carefully, and enjoy, W2
Well, I am back from an exhaustive top shelf scientific study of the situation. I did a 75 mile tour today in dry, then VERY wet weather. I used 4 dual spark plugs and the seat of the pants difference in all variables tested was a big 0. I could tell no difference in top speed, acceleration, idle, or any other area of performance. My fuel consumption was just under 20 MPG, about normal for this time of year. Will take them out for examination later.