Bonneville America Forums Forums Technical Forums General Tech Nology coils:any1 gap thier plugs wider with them?

Papadean has said many times that a wider gap is where it's at as far as getting more power from the ign. From looking at his archived posts he seems to suggest the possibility that with something like the nology coils you may be able to use a wider gap and therefore see a boost in power that most have said they didn't notice with those coils. So what i want to know is has anyone who has nology coils tried widening the plug gap past the stock max? If so, what resulted? If not, hows about one of you nology guys try this and see what results? I'd love to know if the stock gap is keeping the nology coils from doing what they're capable of.

What are the comparative voltages of stock and Nology?
If there is a significant difference, then you could probably get a hotter spark with a wider gap. BUT, that spark would be of shorter duration. Sometimes, and I think especially with carburetion, a cooler, longer lasting spark will give you better burning than a short, hot spark. And even more so if you have enriched your fuel mixture significantly. Here's how it works (exaggerated and simplified)). When you have well vaporized fuel mixed with air at the proper ratio, a short hot spark will ignite the whole mess instantaneously. When your fuel is flying around the cylinders in big drops, a short, hot spark may not ignite it if it doesn't hit a droplet of fuel, a longer spark will hit the fuel and thus cause ignition.
That's why magnetos with their extremely long, albeit cooler spark have been the ignition of choice for top fuel dragsters, with all those big drops of nitro-methane flying around the cylinder, you want to be sure to hit one with the spark.

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then you could probably get a hotter spark with a wider gap. BUT, that spark would be of shorter duration.

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The spark will be present as long as the potential difference is present ie Voltage. Regardless of gap measurement.
NO relationship between gap measurement and time.

Oooookayyyyyyy......so, what does this mean in relation to my question? Not questioning anyone's authority at all, just asking because i know nothing about this and i'm still wondering whether these coils would allow a wider gap. Any thoughts on whether or not you could do this, or do you need some specs on the nologys to comment?

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do you need some specs on the nologys to comment?

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Yes, as compared to stock.

The benefit of a wider gap comes from its ability to start ignition process better.

In the past, I've used the analogy of trying to start a bonfire with a match, as opposed to a plumber's blow torch. (Probably only oldtimers remember those pump-up, kerosene fired rigs.)

In the first year of GM's HEI ignition system on prodution cars (c. 1974), the factory spec. for plug gap was .080". They later backed off to .060", as that large gap was eventually hard on the secondary ignition system (plug wires, dist. cap and rotor). As that secondary system aged, it broke down and allow the spark to jump to ground in various places, taking the path of least resistance.

Remember that the reason Detroit auto makers went to a high output ignition system was to be able to get the combustion flame front going in a very lean situation, and as a secondary reason, to help get closer to complete combustion. All this was driven by new, tougher smog laws that were imposed by the Feds.

Don't forget that using a larger plug gap may effectively lean your carb settings, and may or may not give you spark knock. There are lots of variables involved in this operation, so a guy needs to do the old "cut and try" method to optimize gap settings for his particular bike engine.

This is the round-about explanation of why wider gaps (usually) make more power: you can run a richer mixture and get it burned, thereby making a little bit more power. These wider gaps can also help give your engine better throttle response.

History lesson: Longer, fatter spark is the forte of magnetos. Until just a few years ago, all blown nitro drag cars used mags. Finally, Mallory changed their system over to an electronic one, using the "mags" as generators, which sent the juice to a "black box", where it got jacked out of sight by large capacitors and toroidal transformers, and then sent to the "standard" coils and thereafter to the spark plugs.

Electronic igntitions do have a higher energy spark, able to jump larger gaps, but, that spark is of shorter duration. To get a longer spark from this type, MSD developed an ignition box that would give multiple spark discharges all the time the engine is running.

This works great at lower rpms, but above about 3000 to 3500 rpms, there's not enough time to get off 3 distinct sparks and the engine "sees" just one, albeit fatter than the usual, electronic spark.

Since that last post of mine is so darned long, I thought I'd use a separate one for this idea:

Would that someone could figure out how to adapt an MSD 5 motorcycle add-on ignition box to the Triumph stock ignition. I don't have a clue. (Hey! I was a business major, not an EE guy. <chuckle>)

well Papa, on a related suject that you've discussed before, today i side gapped a pair of NGK's. I'd been using irridums and got a definate increase in midrage performance. Not huge of course, but esily noticable when A/B'ing them with stock plugs.

Anyways, i hate saying anything about this kinda stuff because people tend to think you're fooling yourself or just plain wacked. But his time i have proof. I will be using side gapped plugs over the iridiums for now on because today i did a test ride with them and was amazed to find 2 very obvious improvments that are documentable. One is the vibration is lessened. I noticed it immediatly when i got on the freeway. but the proof is that my left aftermarket mirror has always vibrated so badly past somewhere between 60-70 MPH that i could not tell what type or even the color of any car in back of me. It was DRASTIC to the point of total uslessness. Today i was able to see clearly at 80 MPH (probably higher but thats as fast as i went) what type and color the cars were, and it was as clear as the right mirror which has always been fine with just minor blur. I mean we're talking a 80% improvment at the very least. And the feel of the bars at speed was smoother than ever.

the second thing was idle. my bike has always fluctuated badly. I come to a stop and it idles around 1500 and over the course of maybe 20 seconds gradually goes down to 1100. But it doesn't just stay solidly at 1100....it flutuates slightly up and down and you can hear the motor sounding less than even to say the least. it got better with irridiums but not a great deal. Today with the side gapped plugs, and i am not exaggerationg i swear, i'd come to a stop light and the tach would immediatly go to 1100 and stay there w/o any fluxuation and the engine sounded perfectly even. It even did that after a high speed freeway run where it usually goes real crazy when i come to a stop. But now it just drops right to 1100 almost instantly and stays for as long as i'm stopped, and it did this at every single stop i made. (probably 20-30 stops) My bike has never even remotly come close to doing that since new.

Now with all the talk of side gapping here and never having seen anyone say they tried it and got equally amazing results, i was almost afraid to say anything for fear of being called a wacko. But i swear this is all true and that both the vibration and idle was vastly improved. Has anyone else found any benefits like this with SG? I'm stoked about this and intend to use side gapped plugs for now on. I may even try side gapping the irridiums. heck, they worked better than the stock plugs when both were unmodified, so maybe side gapped they'll be even better still?

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This is the round-about explanation of why wider gaps (usually) make more power: you can run a richer mixture and get it burned, thereby making a little bit more power. These wider gaps can also help give your engine better throttle response

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Right you are, but remember, the ignition system has to be able to produce sufficient voltage to run a wider gap. On those early HEI GM cars, you could see on the scope that it was taking 25kv to 30kv to spark. 20kv was about max for non-HEI. Also once the plugs (fuel) fouled on an HEI car, you had to take 'em out to clean or replace, on a standard (for the day) ignition, if you got it started, the plugs would clean up on their own.

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well Papa, on a related suject that you've discussed before, today i side gapped a pair of NGK's. I'd been using irridums and got a definate increase in midrage performance. Not huge of course, but esily noticable when A/B'ing them with stock plugs.

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Side gapping works. You'll have a reduced plug life, possibly a significant reduction, you'll just have to see. But these plugs are cheap and easy to get to.

Funny thing is tho, you're the only person besides me thats outright said it works. there are tons of thoughts on it but i've yet to see a post where someone says it work except you. But it's one of those things where i just say to myself why the heck isn't everyone doing this? As for the reduction in life, heck, these things probably last 30-50k miles so yes, it IS cheap. even at 10k it's pocket change. what? $5 a pair 10 times @reduced lifespan during a 100k lifetime. $50 instead of $25 for better performance? He|| yeah !

BigBill makes some interesting points about igntions. Which leads me to say this: one can "side gap" his plugs, and/or "wide gap" his plugs.

Opening up the gap from the stock .035" to say, .045" or more, usually takes more voltage capability to effectively jump the gap.

Side gapping a plug and staying at the stock gap setting of .035" shouldn't require any more spark energy, though.

Old original Champion race plugs were manufactured as side gapped, in a special way. For Indy car engines (turbo'd) and for nitro burning drag cars, not only was the plug very cold, the side electrode was a separate round piece that was stuck in through the side of the plug threads (and gapped at .016") through a hole in the metal plug body.

It took a special tool (made by Champion) to adjust the gap on these plugs, though almost no one did that. My buddy used some of these old Champs in his nitro funny car and I opened up the gap to around .030" on them, since I had installed an MSD electronic ignition on his car. (This was in the mid '80's, by the way, and almost nobody ran an electronic ignition then in nitro cars.)

There are other very interesting/strange plug styles, particularly on the older Mazda rotary engines. Aircraft have some different side (also called ground ) electrodes. The old Kawasake tripple 2 strokes, and some outboard marine engines, used a suface gap plug, which had no side electrode at all. The spark jumped right to the plug body ring. Years ago I remember learning of some Stock Eliminator drag guys who cut off the side electrodes of their plugs with nippers! They were able to get away with this because they had low compression engines and aftermarket ignition systems (allowed by the rules).

Oh my, oh my! I've forgotten to talk (OK, I'll make it brief) about combustion pressure and how it affects the spark plug opperation.

As the combustion pressure goes up, for whatever reason, the resistence to the spark jumping the gap increases. Even if you have a stock ignition, under easy operating circumstances you shouldn't have too much, if any, trouble with the way your engine runs. But, as soon as you load the motor by going up a hill, or whacking the throttle wide open, or carrying your fat bro-in-law as a passenger, the spark may not jump the gap very well, if at all.

That is to say, during some running periods, your igntion doesn't need to be high output, and it only puts out as much voltage as is needed. But, as the requirements go up, then the ignition needs to be able to follow along. Again, BigBill refers to that above.

As engine rpms increase, so does combustion pressure. As your compression ratio increase, same-same. Advancing the engine spark timing does this, too, as the burning starts sooner - before the piston gets to TDC - and there is more resistence. (This is especially noticeable at low rpms.) Higher engine heat increases combustion pressure, too, as does better sealing piston rings (think gapless style here).

A better igntion system seems to be the last big mod for the Hinkley twin, as all the other areas have been covered (bigger bore; longer stroke; bigger carbs; ported and big valve heads; bigger cams; freer flowing exhausts). Slowly some bits have become available, such as better coils and ignition wires. The black box is the last piece of the puzzle.

Wow. It's 2:30 am, Mountain Standard Time. Time for ol' GrandpaBauer to hit the hay!

Sounds like something I will have to try this weekend!!