Re: Coil Question

Posted by Mark on February 16, 2004 at 06:18:42 from (199.46.199.232):

In Reply to: Coil Question posted by Peabody on February 15, 2004 at 18:00:33:

Peabody,

I may be steering you wrong here but I have been interested in things like "what parts get changed when you go from a 6 to 12v conversion"? The name of the game is "energy to jump the sparkplug gap".

The points are a switch that lets current from the battery flow through the coil. While doing that it is filling the coil with "energy". The name of the game is to just put enough current into the coil [in the time allowed by what's called "dwell"....hence how long you stay (dwell)] to satisfy the energy requiement of the plug selected.....what is it's temp range and how wide is the gap.

If you run the current too high (put in more energy than the plug needs) you reduce the life of the points as when the points open there is a spark (caused by the coil) and the energy in that spark determines the damage to the points for that firing. (That's why on transistor ignitions, points last forever. A transistor is switched by the points and it electronically does the switching....course they have problems with not enough current to keep the points "clean".

I have been told that 12 volt coils are just 6v coils with an internal ballast (current limiting) resistor. Some have a sign on the side stating that fact. When you Ohm out the primary of your "12v" coil, you should read at least 2 Ohms.

My experience with primary (distributor) circuits is that there is somewhere between 2 to 6 ohms of resistance in the circuit going from the battery thru the coil primary, thru the points and to gnd.

If you go to the auto parts store and get an adjustable ballast resistor, you could set the value yourself. Put the resistor in series with the coil lead mentioned just above. Set the tap on the maximum resistance (6 ohms?). Attempt to start the engine. If you have adequate spark stop there and leave it alone. If not reduce the resistance to 4 ohms then 2 ohms if necessary. If nothing else is wrong you will get the desired result.

Need more, ask.

Mark

Follow Ups:

• Re: Re: Coil Question Mark 13:06:18 02/16/04 (1)
  • Re: Re: Re: Coil Question Seifdoggy2 19:27:21 02/17/04 (0)

Post A Followup Name: E-Mail: Subject: Re: Re: Coil Question Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]