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EA81, 2 separate ignition systems


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GD, I'm thinking close to same as you. Power is proportionate to the amount of fuel/air one can get into and out of an engine. but by same token, one thing one does before taking off in piston powered aircraft is to shut off one mag, back to 2, then shut off other mag. (2 plugs in each cylinder.) RPMs do drop when one does such. If the drop in RPM is too much, one might not want to take off. Also, if spark does not, why is everone putting in the HE coils?

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I disagree with the general, more spark will provide more power by burning the fuel more completely.

Two separate systems would be overkill, though, not to mention expensive. A stock system can only take so much. Double high energy systems would probably burn up the plug electrodes or wires.

I highly recommend the Accel SuperStock coil if you have electronic ignition, but some people have been reporting failures lately.

I've had them on both my cars for years and have not had a single problem.

There is an immediate increase in ease of starting, off-idle acceleration, top-end grunt, and mpgs.

You have to open up the spark-plug gap to take advantage of the hotter spark. I run .045.

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So, I have this new magic sparkplug in mind. It will have 2 totally individual sparks and by a secret manner, which I will not explain, both sparks are far enough apart and will not blind each other from the issue at hand. More power with my dual ignition system?

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Weellll, since it's *magic,* sure, that'll do it!

lol

Seriously, if you can provide two completely independent sparks, it surely will create more power. I doubt it would be cost-effective, though.

shadow, since I was the 1st one to mention spark plug gap, it's fairly obvious your statements were aimed at my comments, but Thanks, I appreciate your concern.

When I 1st put the Accel on FERTHER, I kept the stock gap of .035 and still noticed an improvement right away. The next time I put in new plugs I opened them up to .045 and enjoyed even more improvement.

As a matter of fact, I *did* think more gap would be better, so I tried .055 in my cast iron /6, but it actually made FURTHER lose power . I set the gap back to .045 and all is well.

For the record, based on my real-world experience, I believe that an Accel(or any other high output coil) installed on a new condition motor of the same vintage *will* show measurable improvement.

No *magic* involved.

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Lots of people belive in lots of stuff that isn't true. Take some physics classes, such as I have done, and I'm sure shadow has too. Really there is almost nothing to be had from installing a high power coil. Other than you may avoid the occasional misfire, and it may help to band-aid an already failing ignition system. It's mostly bunk guys. Everyone wants a free lunch, and I'm sorry to say that there isn't one here to be had.

 

GD

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I agree. Only differance I noticed when I put the SuperStock coil in was Suby idled smoother. Doesn't hicup so much anymore. As far as better performance in the seat of the pants, no I really didn't notice any. Mileage may have increaced by about 2 maybe 3 mpg. But with my lead foot, it don't really make muuch differance in the mileage area, I still get 22mpg ona REALLY good day. Last fillup with 100% city driving: 255 miles, 13.5 gal of fuel.:eek:

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corporal chaos, I've had it with your pompousness, and won't try to reason with you again.

You're not the only one who went to school, and implying that I did'nt is incredibly arrogant *and* an insult. One of the moderators should spank you.

Unless you have some real, hands-on experience in the matter you're just blowing hot air. You, sir, may stick it where the light doesn't shine and STFU.

I believe in what I can show to be true, and this lunch wasn't free. It cost me $30.

I stand by my statements because I can demonstrate them, but I won't waste my time on ludites anymore.

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Ya'll, I'm ashamed.

I know better, and I feel badly.

Please forgive me.

General Disorder, I apologize. Let's call a cease-fire.

The shadow is correct. We need to stick together and share our knowledge.

shadow, Thanks for the shot of sanity. I had a bad week, but that's no excuse, just a reason.

C150L, sorry for trampling on your post. Let's return to the subject.

Will you tell us how you intend to provide 2 discrete sparks per cylinder?

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I'm in no way implying that you are uneducated. Education is a broad term that encompases many types of knowledge on many different subjects. I was simply saying that a review of some applicable physics material would be helpful in explaining some of this. I don't wish to offend, just to debunk this myth which is so prevelent.... it's just like recycling - costs more and bad for the environment - but it does make the pleebs FEEL GOOD.

 

And certainly if adding the coil improves the quality of your idle, and the throttle response from a dead stop at idle, I could see where someone might consider that a performance boost. But I also know that a properly functioning stock system can do the same thing. The EA81 is an 8.7:1 compression N/A engine in stock form - it does not have the ability to pull in enough mixture to need a huge hot spark for ignition.

 

The spark is just what starts the controlled burn of the fuel-air mixture. The flame front travels downward from the point of ignition until it contacts the head of the piston, forcing it downward. It matters very little how big this spark is, or how far it jumps. Just so long as it's enough to light off the burn. The problems come when the spark is too weak to light the mixture at all - causing a misfire, and loss of power, rought running ect. It is VERY difficult to notice a misfire that occurs only 2% of the time, so if adding the accel coil reduces that to .1%, then a "magical" performance boost will be seen. However, this is not because the coil is "hotter" but simply because you have reduced the frequency of misfire's in the system. A properly functioning stock system should not have any misfires to speak of anyway, and thus a hot coil should not have any real effect.

 

As for multi-spark situations, I can see how multiple flame fronts traveling from different angles would cause some interesting interactions.... I would have to see some data to know more about how that interaction affects performance. I can conjecture that two flame fronts (if properly aligned in both time and space) could cause the burn to occur faster, and thus you could change the timing of the engine over the entire RPM range.... an interesting concept indeed.

 

GD

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OUCH! OOOO! HOT! HOT! Na, all in fun. (I think.) No appologies required but thanks anyway.

 

I guess I'm going to go with the idea that higher energiy to the spark plugs will make an improvement. Doesn't higher voltage carry easier through a conductor than a lower voltage? If such would be the case, I would think there would be more on the end of the line to do the task at hand. When I put in the Mallory dual point disty and high energy Mallory coil in my Road Runner, if better handled the more fuel/air I was cramming into my 440 through the Six-Pac. Perhaps by just eliminating the "intermittant miss" as stated above. The stocjk ignition in that case was all in new condition, the the Mallory made a huge difference. No physics classes here either, so perhaps I'm wrong too.

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Is it possible that a stock coil may start to produce weak spark at higher rpms? Ive heard this is a problem with 8 or more cylinders on a single coil. I have never seen a motor over 8 cyl without dual or independant coils. My father, who has a phd in math and a masters in physics says that this could be a problem as the frequency limit of the inductor (coil) is approached. An aftermarket coil has more windings to create a higher voltage. This would actually make the frequency limit lower, because the time required for the magnetic field to be set up, as the voltage climbs from 0 would be greater. Hence drops would be greater at high rpms. But on a 4 cylinder, I don't think this would be as relevant, because there are less fires/sec for the coil to deal with. Just another point to analyze, another angle to look at this subject from.

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