Wildguzzi.com

General Category => General Discussion => Topic started by: Chuck in Indiana on January 27, 2015, 05:44:21 AM

Title: Modern coils for points system?
Post by: Chuck in Indiana on January 27, 2015, 05:44:21 AM
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
(http://i29.photobucket.com/albums/c294/elwood59/aero%20engine/1-001_zpsuemspt2l.jpg) (http://s29.photobucket.com/user/elwood59/media/aero%20engine/1-001_zpsuemspt2l.jpg.html)
Title: Re: Modern coils for points system?
Post by: Dick on January 27, 2015, 06:06:07 AM
My simple answer, without any explanation, would be yes.  ;D
Title: Re: Modern coils for points system?
Post by: pauldaytona on January 27, 2015, 06:30:59 AM
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?
Title: Re: Modern coils for points system?
Post by: Dick on January 27, 2015, 06:50:45 AM
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 ?
Title: Re: Modern coils for points system?
Post by: Rough Edge racing on January 27, 2015, 06:57:19 AM
 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.
Title: Re: Modern coils for points system?
Post by: Chuck in Indiana on January 27, 2015, 07:03:51 AM
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?
Title: Re: Modern coils for points system?
Post by: guzziownr on January 27, 2015, 08:48:57 AM
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...
Title: Re: Modern coils for points system?
Post by: kckershovel on January 27, 2015, 10:52:25 AM
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?
Title: Re: Modern coils for points system?
Post by: Antietam Classic Cycle on January 27, 2015, 11:03:47 AM
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.
Title: Re: Modern coils for points system?
Post by: Chuck in Indiana on January 27, 2015, 11:09:25 AM
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..
Title: Re: Modern coils for points system?
Post by: kckershovel on January 27, 2015, 11:14:43 AM
Chuck would the coils be wired in series in your application?
Title: Re: Modern coils for points system?
Post by: Rough Edge racing on January 27, 2015, 11:42:16 AM
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...
Title: Re: Modern coils for points system?
Post by: guzziownr on January 27, 2015, 11:52:23 AM
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
Title: Re: Modern coils for points system?
Post by: Chuck in Indiana on January 27, 2015, 11:55:07 AM
Chuck would the coils be wired in series in your application?

Power is jumpered from one coil to the other.
Title: Re: Modern coils for points system?
Post by: Rough Edge racing on January 27, 2015, 11:57:50 AM
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 ?
Title: Re: Modern coils for points system?
Post by: Chuck in Indiana on January 27, 2015, 11:58:53 AM
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
Title: Re: Modern coils for points system?
Post by: Chuck in Indiana on January 27, 2015, 12:01:30 PM
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:
Title: Re: Modern coils for points system?
Post by: kckershovel on January 27, 2015, 12:33:05 PM
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.
Title: Re: Modern coils for points system?
Post by: guzziownr on January 27, 2015, 12:52:49 PM
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."
Title: Re: Modern coils for points system?
Post by: kckershovel on January 27, 2015, 12:54:31 PM
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.
Title: Re: Modern coils for points system?
Post by: Triple Jim on January 27, 2015, 12:58:10 PM
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.
Title: Re: Modern coils for points system?
Post by: kckershovel on January 27, 2015, 01:04:55 PM
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?
Title: Re: Modern coils for points system?
Post by: smartin108 on January 27, 2015, 02:01:51 PM
He has two sets of points, so the coils have to be independent an therefore wired in parallel.
Title: Re: Modern coils for points system?
Post by: Rough Edge racing on January 27, 2015, 02:20:07 PM
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...
Title: Re: Modern coils for points system?
Post by: kckershovel on January 27, 2015, 03:03:48 PM
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.
Title: Re: Modern coils for points system?
Post by: pauldaytona on January 27, 2015, 03:18:01 PM
It's amazing that Americans came to the moon so many years ago. I suppose no coils in a rocket. 
Title: Re: Modern coils for points system?
Post by: smartin108 on January 27, 2015, 03:28:10 PM
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.
Title: Re: Modern coils for points system?
Post by: tusong200 on January 27, 2015, 03:54:57 PM
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.
Title: Re: Modern coils for points system?
Post by: Triple Jim on January 27, 2015, 03:58:59 PM
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.
Title: Re: Modern coils for points system?
Post by: tusong200 on January 27, 2015, 04:02:44 PM
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.
Title: Re: Modern coils for points system?
Post by: Antietam Classic Cycle on January 27, 2015, 04:13:37 PM
It's amazing that Americans came to the moon so many years ago.  

You live on the moon? Cool!  ;D

Title: Re: Modern coils for points system?
Post by: Chuck in Indiana on January 27, 2015, 04:51:46 PM
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.

Thanks.  ;D Bought it many years ago (it seems all my tools are antiques)  ??? to tune up the feed back circuits on my cnc mill.
Woo wee, wat a can of worms. Here I was, happily working out in the shop fitting up the wings on the Lario, thinking I had the coil problem under control, and this is almost like an oil thread.  ;D :BEER:
Title: Re: Modern coils for points system?
Post by: kckershovel on January 27, 2015, 05:10:27 PM
Sounds like it's all worked out then. Glad I could muddy the water.
Title: Re: Modern coils for points system?
Post by: tusong200 on January 27, 2015, 05:34:09 PM
Thanks.  ;D Bought it many years ago (it seems all my tools are antiques) 

I've got the same one... bought about 30 years ago.
Title: Re: Modern coils for points system?
Post by: Rough Edge racing on January 28, 2015, 05:28:25 AM
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.

Two 3 ohm coils wired in parallel remains 3 ohms each, wired in series would be 6 ohms...
Title: Re: Modern coils for points system?
Post by: kckershovel on January 28, 2015, 08:02:08 AM
If they are truly wired in parallel I disagree. It does not apply to the Guzzi though so this would just be for arguments sake. 
Title: Re: Modern coils for points system?
Post by: pauldaytona on January 28, 2015, 08:44:19 AM
Two 3 ohm coils wired in parallel remains 3 ohms each, wired in series would be 6 ohms...

No!

When wired in parralel, the load that the source sees is 1.5 ohms. You will never change the internal resistance of the coils, that stays 3 ohms in any situation.
When wired in series, the load that the source sees is 6 ohms.
Title: Re: Modern coils for points system?
Post by: kckershovel on January 28, 2015, 09:32:28 AM
No!

When wired in parralel, the load that the source sees is 1.5 ohms. You will never change the internal resistance of the coils, that stays 3 ohms in any situation.
When wired in series, the load that the source sees is 6 ohms.

This I agree with
Title: Re: Modern coils for points system?
Post by: Kiwi_Roy on January 28, 2015, 09:44:11 AM
The coils have a common supply, they are not in series or parallel for that matter.
You really can't apply transformer theory, the spark is caused by the magnetic field collapsing, true the
ratio of the Voltage on each winding will be determined by the ratio of turns in the windings but 12 Volts
doesn't come into it, the Voltage on the primary as the field collapses will be many times that, if you were
holding the points terminal you might get a nasty jolt as the points open.
Title: Re: Modern coils for points system?
Post by: kckershovel on January 28, 2015, 08:27:08 PM
Many coils are acutely designed to see 6-9 volts even in a 12 v system while we are adding information. 
Title: Re: Modern coils for points system?
Post by: Rough Edge racing on January 29, 2015, 07:06:10 AM
 When discussing ignitions systems like a Guzzi, two coils ,each feed by a common electrical source are wired in parallel. In this case parallel refers to the power source just like the light bulbs in your home. This does not change the primary resistance of each coil. The voltage at the condenser when the points open can be around 300 volts.
Title: Re: Modern coils for points system?
Post by: Kiwi_Roy on January 29, 2015, 10:15:16 AM
If both coils were operated by the same set of points sparking at the same instant I would agree they are in parallel
They are really 2 separate circuits fed from the same fuse, they operate independently
 
From an electrical point of view two devices with both leads joined together are in parallel

I think we are both saying the same thing really, let's agree to disagree.

300 Volts on the condenser, I suspected it was high, I have had several nasty bites from low Voltage solenoids and seen the guts blow out of electronics not designed to handle it
Title: Re: Modern coils for points system?
Post by: kckershovel on January 29, 2015, 10:29:31 AM
    Right since the Guzzi has dual points the 2 coils are not wired in series or parallel so there is no change in ohms. When I originally asked the question I was not sure how the Dyna S ignition was wired into the Guzzi.

    I have more HD background and most are single points so the series and parallel question does apply to them. With the option of single or dual fire along with single or dual plug heads there are allot of possible combinations.   
Title: Re: Modern coils for points system?
Post by: Wayne Orwig on January 29, 2015, 10:34:05 AM
the Voltage on the primary as the field collapses will be many times that, if you were
holding the points terminal you might get a nasty jolt as the points open.

I did a tachometer design long ago which was attached to the primary. I often saw voltages well over 400 volts on the primary.
Title: Re: Modern coils for points system?
Post by: Rough Edge racing on January 29, 2015, 10:44:18 AM
 Civilized disagreement is a learning process... ;D