Modern coils for points system?

[Chuck in Indiana]

I've never heard anything good about the stock coils in the Lario. I have these new coils off the aero engine, but I've only seen them on computer bikes. They are small, and would fit nicely, but only check at .8 ohms. Is it possible to use them with the Dyna S with a resister? What I don't know about this kind of thing would fill several volumes..  ;D

[Dick]

My simple answer, without any explanation, would be yes.  ;D

[pauldaytona]

If your dyna s is for 5 ohm coils, then 0.8 ohm won't go with resistor. To reach 5 ohm, you would need a 4.2 ohm resistor.Most voltage will drop over the resistor, and little to the coil.  That gives 10.7 volt for the resistor and 1.9 volt for the coil. Small spark.  Dyna coils?

[Dick]

My simple answer, without any explanation, would be yes.  ;D

Simply wrong, I guess. ;D

Are the Dyna S ignitions (without black box) as sensitive as the Dyna III, as coil resistance goes? Maybe wouldn't need to go 5 Ω ?

[Rough Edge racing]

 I've messed around with a lot of car and bike ignition modifications. 3 ohms is the minimum for a Dyna ( some might say 5 ohms is safer) or points on 12 volts . Be better to find different coils than try and add that much resistance.
  Since Kettering invented the coil type ignition and first offered on Cadillac in 1910  materials have changed but the basic principal is the same even with modern electronics.

[Chuck in Indiana]

I kind of *assumed* as much in the aero thread.
Ok, I have one new green Dyna coil. Naturally, they're sold in pairs.  ::) Anyone have one they want to sell?

[guzziownr]

3 ohms is the minimum for a Dyna ( some might say 5 ohms is safer) or points on 12 volts

I might say it after my 3 oh coil melted and took the Dyna box with it...

[kckershovel]

So if both the coils were wired in series the resistance would be 1.6 ohms add in a 1.5 ohm resistor and you are where you need to be. Or am I missing something?

[Antietam Classic Cycle]

Bosch Blue Coils or Flamethrowers? Just bought the Bosch Blue at Advance Auto for $26.99. Only downside on a Lario is finding a place to put them.

[Chuck in Indiana]

Bosch Blue Coils or Flamethrowers? Just bought the Bosch Blue at Advance Auto for $26.99. Only downside on a Lario is finding a place to put them.

Yeah, I snatched some Flamethrowers off of Amazon last summer. Didn't realize just how big they are, and sent them back. There just isn't much room on the Lario..

[kckershovel]

Chuck would the coils be wired in series in your application?

[Rough Edge racing]

I might say it after my 3 oh coil melted and took the Dyna box with it...

 My Guzzi had 3 ohm coils on it for many years and then one coil failed...When in doubt ask Dyna...Dyna says the stock coils are fine...Many Guzzi's have 3.2 ohm coils...

[guzziownr]

My Guzzi had 3 ohm coils on it for many years and then one coil failed...When in doubt ask Dyna...Dyna says the stock coils are fine...Many Guzzi's have 3.2 ohm coils...

Yeah, they were dyna coils...  Dyna changed their mind about them at some point and started recommending 5 oh.  My investment went (removes sunglasses) up in smoke  :D

[Chuck in Indiana]

Chuck would the coils be wired in series in your application?

Power is jumpered from one coil to the other.

[Rough Edge racing]

I kind of *assumed* as much in the aero thread.
Ok, I have one new green Dyna coil. Naturally, they're sold in pairs.  ::) Anyone have one they want to sell?

Chuck I have one green Dyna single output 3 ohm coil. It's a good used one and it yours for the price of shipping... But according to the poster above Dyna says 5 ohm now ?

[Chuck in Indiana]

Simply wrong, I guess. ;D

Are the Dyna S ignitions (without black box) as sensitive as the Dyna III, as coil resistance goes? Maybe wouldn't need to go 5 Ω ?

The only other experience I have with the Dyna S is on the secondary ignition system of my homebuilt airplane. It uses the green coils, and has been reliable for many years. That's about the sum total of my knowledge with Dyna systems.  ;D

[Chuck in Indiana]

Chuck I have one green Dyna single output 3 ohm coil. It's a good used one and it yours for the price of shipping... But according to the poster above Dyna says 5 ohm now ?

Alrighty, now.  ;-T I'll PM you my info. PM me yours, and I'll send some beer money.  ;D :BEER:

[kckershovel]

Ok if power is jumpered from one coil to the other they would be in series and you would add the ohms of each coil together 1.6 ohms. If it were me I would use the coils you have with a resistor wired inline before the first of the two coils. With a common 1.5ohm coil that would put you in the 3.1-3.2 range.

[guzziownr]

From the Dyna FAQ:

"For breaker points ignitions use 5.0 ohm coils or 3.0 ohm coils with a 1 to 2 ohm ballast resistor in series with the +12 volt supply wire to the coil. Dynatek cannot be responsible for ignition or coil problems that result from using a coil of incorrect primary resistance with a particular ignition system."

[kckershovel]

Right 5 ohm or 3 ohm total you have to add the ohm values together when using 2 wired in series. Just to be sure the jumper goes from the - on the first coil to the + on the second coil correct? If so that is series wiring. Here is a NAPA pn ICR13 – 1.82 ohms resistor 11.47 in-stock at my home location. I would do like the automotive industry did and bypass the resistor for starting.

[Triple Jim]

Ok if power is jumpered from one coil to the other they would be in series and you would add the ohms of each coil together 1.6 ohms.

I think Chuck is saying the power is jumpered to both coils in parallel, and they are fired separately by two different wires to the negative terminals.

[kckershovel]

If they are wired in parallel that cuts the total ohms in half. so his coils definitely would not work and he would only be at 1.5 ohms with 2 3ohm coils and would still need the ballast resistor. Better would be to have 2 5ohm coils at that point giving 2.5 ohm when wired in parallel. Still needing a resistor.

Chuck please confirm. Does the power wire from the first coil go to the negative or positive terminal on the second coil?

[smartin108]

He has two sets of points, so the coils have to be independent an therefore wired in parallel.

[Rough Edge racing]

From the Dyna FAQ:

"For breaker points ignitions use 5.0 ohm coils or 3.0 ohm coils with a 1 to 2 ohm ballast resistor in series with the +12 volt supply wire to the coil. Dynatek cannot be responsible for ignition or coil problems that result from using a coil of incorrect primary resistance with a particular ignition system."

It's interesting that Guzzi used 3.2 ohm cannister coils with points and breaker life wasn't an issue from what said on this forum. I'm thinking the oil filled canister coil can deal with heat better than the modern E core Dyna coil or than the Dyna makes the same spark on less current or something like that...

[kckershovel]

With this information I would want to start with 5 ohm coils and wire in a ballast resistor as well. That is probably why Guzziownr got a melted box with the 3 ohm coils not realizing that when wired in parallel they become 1.5 ohm coils.

[pauldaytona]

It's amazing that Americans came to the moon so many years ago. I suppose no coils in a rocket. 

[smartin108]

It's amazing that Americans came to the moon so many years ago. I suppose no coils in a rocket. 

They used Flux Capacitors instead.

[tusong200]

Hmmmm???

The coil is a step-up transformer. You put 12V in (primary side) and you get whopping volts out so it can jump the spark plug gap (10,000V+, secondary side).

The ohm rating is just a means of comparing one coil flavor/variety to another because it's easy to measure. What you are measuring is the resistance in the length of wire on the secondary side. This resistance is caused by the length and diameter of the wire. The important thing is the number of windings/turns on primary and secondary sides (relation to each other). This is what creates the voltage step up.

If you double up coils in series you'll have 10K+ Volts on the primary side of the second coil...not good. Parallel doesn't seem workable...it might not have any effect at all because the relationship of the primary and secondary windings might not be any different. Not sure..I'd have to draw it out.

It's not about ohms...it's about voltage. Use stock parts from what ever source you choose....follow their recommendations. Only they know the internal construction of their coils, that is, the size of the wire they use and how many windings on each side.

[Triple Jim]

With this information I would want to start with 5 ohm coils and wire in a ballast resistor as well. That is probably why Guzziownr got a melted box with the 3 ohm coils not realizing that when wired in parallel they become 1.5 ohm coils.

I said they're in parallel, but that's not really an accurate statement.  Both coil + terminals are connected to 12V.  The negative terminals get grounded by the points or transistor assisted system intermittently.  The coils fire independently, one for each cylinder.

[tusong200]

To be clear...They're not in parallel cuz they're never in the circuit at the same time.

By the way Chuck, Nice Fluke.