For the Iggy technoids.

[backlander]

Yes, thanks Gary, very good information that is much appreciated. Thanks for your time and input. Keep it coming, we're like sponges.

 

[PowerArc]

Tach Talk

One of the most asked questions is which tachometer do I use. Let’s start out by defining what a tachometer is and what it reads.

A tachometer (revolution-counter, Tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a shaft or disk, in an automotive engine this is normally of the crank shaft.

Early tachometers were driven by a rotating cable from a drive unit fitted to the engine (usually on the camshaft) and were usually on engines with basic or no electrical systems. Later tachometers are most simply looked as a pulse counter, counting the pulses (on/off) cycles of the ignition coil.

Let’s look at 4 cycle engines with distributors first. The distributor distributes the spark generated by a single coil output to the all cylinders at the appropriate time. Since the piston is only on the compression stroke every other rotation of the crank the cam is used to distribute the spark as it runs at ½ the speed of the crank. Since all cylinders will fire in 2 rotations of the crank and the firing order is defined, the distributor rotor will direct the spark to ½ the cylinders in a ½ rotation of the distributor and the rest of the cylinders in the 2nd ½ rotation of the distributor. i.e. in a V8 with cylinder order of 1-8-4-3-6-5-7-2 you would fire 1-8-4-3 in the first revolution of the crank and 6-5-7-2 in the 2nd giving you 4 coil firings each rotation of the crank or 4 pulses thus a 8 cylinder tach.
A 4 cylinder distributor based system would have 2 pulses per crank revolution and a 6 cylinder would have 3.

Now let’s look at a wasted spark system which normally has 1 coil per 2 cylinders and is how most engine ignitions are 1 - 8 cylinders now. Since a wasted spark system fires each of its coils 1 time per crank revolution you could use a 1 pulse per crank revolution tachometer to any 1 of the coil triggers and have the tach read correctly.
1 pulse per revolution tachometers are the most common and reasonably priced on the market.

Yes, absolutely a Goldwing is a wasted spark system and you can hook a 1 pulse per revolution tachometer to the trigger wire of 1 of the 2 coils and it will read correctly. You don’t have to use the cable drive tachometer.

A single cylinder system becomes a bit tricker, if the points or pickups are located on the cam you will get 1 pulse per 2 revolutions of the crank. If located on the crank you will get 1 pulse per crank revolution and the coil fires in on the compression stroke of the engine and also the exhaust stroke of the engine. A common example of this is your single cylinder lawn mower engine with the points on the crank. Bet you didn’t realize your lawn mower was a was wasted spark engine.

To select the tach you need requires knowing the number of pulses per crank revolution.

Multi Spark will totally mess up your tachometer readings and so will many other situations so the better ignition companies will supply you with a corrected tachometer output signal.

Some manufactures have now changed their tachometers so they are just a voltmeter the reads a voltage output from the electronic ignition module and the voltage corresponds to the RPM.

Picture of a 2 cylinder single fire coil (1 core per cylinder) vs 2 cylinder wasted spark coil (dual fire)

 

[89-300ce]

The bosch micro relays look to be rated at 20-30amp. Could these, triggered by the spark module, be used to feed the neon coils?

 

[joedrum]

hmmmmm....yes im thinking no problem at all .....but it sould be relayed in right spot and right trigger wire ..for everything to work right

 

[dan filipi]

89-300ce » Fri Aug 16, 2013 8:33 am[/url]":2rmeabas]
The bosch micro relays look to be rated at 20-30amp. Could these, triggered by the spark module, be used to feed the neon coils?

I highly doubt a relay could switch as fast as is needed to power coils but I could be wrong.

 

[joedrum]

no idont think it can go there but it could be used as iggy overall clean voltage .. the other hmmmm don't know it would work like dan was saying either

 

[AApple]

89-300ce » Fri Aug 16, 2013 10:33 am[/url]":xl6zeyhh]
The bosch micro relays look to be rated at 20-30amp. Could these, triggered by the spark module, be used to feed the neon coils?

Maybe to power the coils, but not to trigger them to fire. They just won't switch quick enough....unless you can find a solid state relay, or what is known as a quad driver...
That's an electronic "relay" that powers/switches up to four different circuits.

 

[dan filipi]

Well the spark units are nothing more than electronic relays so you could be on to something concidering they're 80's tech they have been working.
Hmm.

 

[PowerArc]

Maybe to power the coils, but not to trigger them to fire. They just won't switch quick enough....unless you can find a solid state relay, or what is known as a quad driver...
That's an electronic "relay" that powers/switches up to four different circuits.

1st no way, but let's look at just 1 aspect. The cycle life of the relays in question are 100,000 to 1,000,000 let's use 1 million. Just for simplicity use the Goldwing engine running at 2500 rpm, the cam would rotate 1250 rpm and the points (relay) would open and close 1250 times a minute. If you consider 2500 RPM = 60 mph then 1,000,000 cycles / 1250 per minute = 800 miles.

Even if you get an electronic relay it is not clamped correctly or not at all, if only it were that easy. There are many many more considerations, most of the relays are available for 4.00 or 5.00 fell free to try it. Oh, please take as much video as possible.

 

[joedrum]

:smilie_happy: :smilie_happy: :mrgreen:

 

[dan filipi]

I gotta wonder exactly what is going on under that black goo in the 1100 spark units.
To my knowledge noone has ever torn into one and documented this.
Seemingly it would be a wasted effort anyhow now that a better system is available, though I am curious.

 

[89-300ce]

PowerArc » Fri Aug 16, 2013 1:24 pm[/url]":b87utmqw]

Maybe to power the coils, but not to trigger them to fire. They just won't switch quick enough....unless you can find a solid state relay, or what is known as a quad driver...
That's an electronic "relay" that powers/switches up to four different circuits.

1st no way, but let's look at just 1 aspect. The cycle life of the relays in question are 100,000 to 1,000,000 let's use 1 million. Just for simplicity use the Goldwing engine running at 2500 rpm, the cam would rotate 1250 rpm and the points (relay) would open and close 1250 times a minute. If you consider 2500 RPM = 60 mph then 1,000,000 cycles / 1250 per minute = 800 miles.

Even if you get an electronic relay it is not clamped correctly or not at all, if only it were that easy. There are many many more considerations, most of the relays are available for 4.00 or 5.00 fell free to try it. Oh, please take as much video as possible.

It's impressive that points survive under these conditions.

 

[PowerArc]

I quoted AApple and forgot to say he is correct! Powering the coils this way could be done but not triggering them.
Apologies AA

 

[jpwinger]

So what is the reistor for in the spark plug caps. And does it tie in to any of this to eliminate heat back up in stock systems with balast reistor in coils.

 

[toytender01]

radio noise suppression

 

[jpwinger]

Thanks Bob. What I'm trying now is going without the reistor and useing solid copper ground wire cut and filed to size of reistor. Jerry :fishin:

 

[dan filipi]

My understanding is ya don't need any resistor on these ignitions.
The copper wire bypass is a good idea. That's what I did.
I think I used #8 solid .

 

[jpwinger]

Seems funny that the spark goes thru that small spring in cap to plug when we need all the spark we can get. Checked out part numbers on plug caps 82 is different than 80. Price sure is different too. 80 coils no balist resitor. 82 coils have one. Wonder what is the differents is in the caps. Jerry

 

[C5Performance]

dan filipi » Fri Aug 16, 2013 2:46 pm[/url]":22t6pla9]
I gotta wonder exactly what is going on under that black goo in the 1100 spark units.

My wife and I were at a MOPAR car show tonight talking about our ignitions. One guy pointed to his ignition (voltage regulator i believe) and showed us where it had leaked potting material down his inner fender and all over the frame. He said it was not that uncommon and it happened on his drag racing car as well, just before it failed.

He was very interested in our new automobile ignitions as a solution to poor quality 1970's car electronics. Funny, the car guys are complaining about the same issues we face with motorcycles, which is why i just ordered our first run of ignitions for American cars.

 

[PowerArc]

Exactly correct, it is a reverting of the potting compound used to back pour the coil, I have seen i happen many times. It's not supposed to do that but does fall with time, heat and vibration.