Plug caps

[3Phase]

Things to ponder:

An ignition pulse (impulse) contains equal amplitude of all frequencies, regardless of the frequency that the pulses occur.

Sound propagation is as you described....lows are omnidirectional, highs are more directional...lows travel farther, etc......but electromagnetic radiation travels differently.

The directionality of the radiation depends on the shape of the radiating device (antenna). For example, a dipole has a figure 8 polar pattern- it can send receive maximum amplitude perpendicular to the wires, but almost nothing parallel to the wires.

The car electronics have specifications for EMC (electromagnetic compatibility). The relevant spec would be called "radiated immunity". Aside from the radio, it would be surprising if the pulses would interfere with anything else.

AM is indeed much more susceptible to interference than FM.

Now, if we hadn't been smoking dope instead paying attention to Laplace Transforms and Fourier Series, we might know something about this ignition system discussion.

Wiki: Major-General's_Song.ogg | Ogg Vorbis sound file, length 2 min 47 sec, 64 kbps

"I'm very good at integral and differential calculus;
I know the scientific names of beings animalculous:
In short, in matters vegetable, animal, and mineral,
I am the very model of a modern Major-General."

Wiki: Major-General's_Song


.

[MPittma100]

The Fix

T.C.,

RF suppression is the electrical engineering equivalent of deburr, fit and finish.

It makes the F.C.C. happy so they don't fine the manufacturer into oblivion and it keeps down the individual and class action lawsuits that claim your noisy ignition kills people by interfering with pacemakers. It makes it harder for the mother ship and the black helicopters to track you too.

.

I'm pretty sure that Al Gore has already come up with a fix for this problem.

[Radioguylogs]

Hey Scott, Steve, even Capt. Zap,

... I understand that the RF could possibly cause problems with sensitive automotive ignition electronics...but I wonder HOW CLOSE the bike would have to be for it to interfere??

Also...with the lower rpm's of our bikes....7500 rpm, 2 spark pulses per rpm due to wasted spark...so ~15,000 per MINUTE...that's only 250 hz! From what I remember low AUDIO frequencies are more omni-directional whereas hi frequencies are much more directional. Also remember that they travel farther easier that higher audio frequencies. I would think that RF is also Omni-directional....but don't know much about their transmission ability? I understand that AM frequencies are more susceptible to RF than FM.

T.C.

Things to ponder:

An ignition pulse (impulse) contains equal amplitude of all frequencies, regardless of the frequency that the pulses occur.

Sound propagation is as you described....lows are omnidirectional, highs are more directional...lows travel farther, etc......but electromagnetic radiation travels differently.

The directionality of the radiation depends on the shape of the radiating device (antenna). For example, a dipole has a figure 8 polar pattern- it can send receive maximum amplitude perpendicular to the wires, but almost nothing parallel to the wires.

The car electronics have specifications for EMC (electromagnetic compatibility). The relevant spec would be called "radiated immunity". Aside from the radio, it would be surprising if the pulses would interfere with anything else.

AM is indeed much more susceptible to interference than FM.

Now, if we hadn't been smoking dope instead paying attention to Laplace Transforms and Fourier Series, we might know something about this ignition system discussion.

[BowlingSS]

T.C.,

RF suppression is the electrical engineering equivalent of deburr, fit and finish.

It makes the F.C.C. happy so they don't fine the manufacturer into oblivion and it keeps down the individual and class action lawsuits that claim your noisy ignition kills people by interfering with pacemakers. It makes it harder for the mother ship and the black helicopters to track you too.

.

Thank is funny...

Bill

[3Phase]

T.C.,

RF suppression is the electrical engineering equivalent of deburr, fit and finish.

It makes the F.C.C. happy so they don't fine the manufacturer into oblivion and it keeps down the individual and class action lawsuits that claim your noisy ignition kills people by interfering with pacemakers. It makes it harder for the mother ship and the black helicopters to track you too.

.

[MPittma100]

Rfi

As mentioned by TC, RFI will likely only be heard from these bikes on AM radios. Probably be so little interference that it will only be heard through the AM side of the radio that is on the bike. Cannot see a reason for a lot of concern there.

[TopCatGr58]

Well, I'm not totally sure about why our bikes use the exposed threaded tip of the plug with the cap that's designed for that type of connection vs. the larger automotive type...but I think it's because the cap has a springy wire that grips the plug/threads a bit better than the automotive type. And that allows the plug to not get wind blown off of the plug compared to the automotive type that doesn't get that level of wind pressure under the hood.

However, when I've tried to remove auto spark plug wires...they seem to be quite secured to the plug with their big boots...so I don't think you would really have any problems with it holding onto the plug with it in the wind. And you say the wire set you have are solid core, so should perform as well...vs. graphite type wires.

T.C.

[dbeardslee]

That sucks about the paint. I've got a paint job ahead of me too. The tank I painted developed a leak, and I haven't gotten around to painting the current one yet.

Here's another thought I've had periodically on plug caps. Whenever I change wires I always get a cheap set of 7mm solid core automotive wires. The one's I've been using are called Pro Series 2403W's, although I'm sure there are a lot of similar universal type wire sets. These always have automotive type plug boots on the wires, and I usually just cut them off and use the wire. But I have toyed with the idea of leaving the little nobs on the ends of the plugs, and just plugging the automotive boots onto them.

This is what the wire set looks like...



The last set of these wires I bought were on close out at Rock Auto. I got the wire set for $3 and change, and even with shipping it was less than $10.

[TopCatGr58]

I'll have to see if the ones I have will come apart? I suspect there's just a SPRING in it. I also am using the 90 degree little ones across all cylinders, have the 8mm solid core silicon wires, so wasn't too worried about them rubbing/wearing thru while laying on the head/valve cover. I might wrap them with some zip ties next time I'm under there....will have to pull the tank eventually since last year I overfilled the tank before loading it on the trailer, and so the fuel leaked out...UNDER the custom paint on one side....big area of bubbled paint! Just too much personal stuff getting in the way right now to be bothered with it.

T.C.

[dbeardslee]

They're on sale here too. I had to order them but they found 4 caps in a store up north.

They're the 90 degree caps for the outer two cylinders. I don't think NGK makes a non-resistor 120 degree cap for the inner cylinders but it looks like the 90s have brand new little rubber feet and collars to seal around the wires and the spark plugs.

.

I've got the little 90 degree non-resistor caps right across the board. I just put a couple zip ties on the wires to hold them up off the motor and away from each other.

Who listens to AM anymore anyways...

Rush Limbaugh?

So TC, what say you on the cap wear issue. Do the non-resistor caps wear out or is it just the resistor caps that have that problem?

[3Phase]

They're on sale here too. I had to order them but they found 4 caps in a store up north.

They're the 90 degree caps for the outer two cylinders. I don't think NGK makes a non-resistor 120 degree cap for the inner cylinders but it looks like the 90s have brand new little rubber feet and collars to seal around the wires and the spark plugs.

.

[TopCatGr58]

Hey Scott, Steve, even Capt. Zap,

Have any of you actually ran your bike and then your car next to it to see if you can perceive any RF in your radio?? I understand that the RF could possibly cause problems with sensitive automotive ignition electronics...but I wonder HOW CLOSE the bike would have to be for it to interfere??

Also...with the lower rpm's of our bikes....7500 rpm, 2 spark pulses per rpm due to wasted spark...so ~15,000 per MINUTE...that's only 250 hz! From what I remember low AUDIO frequencies are more omni-directional whereas hi frequencies are much more directional. Also remember that they travel farther easier that higher audio frequencies. I would think that RF is also Omni-directional....but don't know much about their transmission ability? I understand that AM frequencies are more susceptible to RF than FM. Who listens to AM anymore anyways....and for that matter FM is on it's way out also with the advent of SATELLITE RADIO, as well as iPads/phones/mp3 players.

SO...I'm not worried about the RF from my Non-resistor caps AND non-resistor plugs. This weekend, I'll see about firing up my bike next to my car and see if I can get any interference with any of the electronics.. it has Fm/Satellite/mp3 aux in capability.

T.C.

[dbeardslee]

Three or four dollars each was about what they wanted here in Simi and they had some fantasy about me paying another couple of bucks for shipping too because they weren't a normally stocked item. I didn't quite tell 'em to pound sand.

I have to go to O'Reilly's to get some more carburetor and brake cleaner, a can of WD-40, and some Plastigauge so I'll see if they have the caps on sale too. Thanks for the heads up!

.

No schveat. It's one of those things O'Reilly doesn't normally stock in the stores, but they can get 'em for you in a couple days. They want $3.69 ea. for the resistor type, but the non-resistors are uber cheap.

[3Phase]

I'm tempted to go buy a new set at O'Reilly's whether it needs them or not. I paid three dollars and change each for the ones that are on the bike at a local motorcycle shop - which kind of pizzes me off when I see them at O'R's for $1.29 apiece.

Three or four dollars each was about what they wanted here in Simi and they had some fantasy about me paying another couple of bucks for shipping too because they weren't a normally stocked item. I didn't quite tell 'em to pound sand.

I have to go to O'Reilly's to get some more carburetor and brake cleaner, a can of WD-40, and some Plastigauge so I'll see if they have the caps on sale too. Thanks for the heads up!

.

[dbeardslee]

Doug,

That is a good question. I honestly don't know how non-resistor caps wear, I've never bought any of them and I've never taken one apart.

I made my own out of resistor caps with a steel slug from a cut off SS machine screw in place of the resistor. They don't seem to be experiencing any wear but thanks for reminding me it's time to clean them in case there's any rust or Galvanism.

.

I'm tempted to go buy a new set at O'Reilly's whether it needs them or not. I paid three dollars and change each for the ones that are on the bike at a local motorcycle shop - which kind of pizzes me off when I see them at O'R's for $1.29 apiece.