[Mgs] Stuff and nonsense

PaulHunt73 paulhunt73 at virginmedia.com
Sun Jan 25 02:36:38 MST 2015

Sounds to me like you might have installed a coil for ballasted ignition on 
an unballasted circuit.  Chrome bumper cars originally had unballasted 
ignition and a 3 ohm coil.  Rubber bumper cars originally had ballasted 
ignition and a 1.5 ohm coil, but owners may have bypassed the ballast so it 
now needs a coil for an unballasted system.  Put the 1.5 ohm coil on an 
unballasted system and it will take twice the current and get twice as hot. 
Sport coils for unballasted systems may measure about 2.4 ohms and for 
ballasted systems about 1.2 ohms, and so get a little hotter than standard 
coils.  You have to ignore what anything on the coil might say, or what is 
on the box, or what the bloke behind the counter and told you, and measure 
the resistance to be sure what you have.

What ignition system do you have?  If the points gap is too small i.e. dwell 
too high that will make the coil run hotter.  Some under-cap fixed-dwell 
electronic triggers have a higher dwell than points and again result in 
hotter coils.  A variable dwell system - if it is working correctly - should 
result in a much cooler coil.  Coils on unballasted systems run hotter than 
coils on ballasted systems.  As to temperatures, I have a ballasted and an 
unballasted.  In winter i.e 10C/50F they have measured about 40C/104F which 
is not much more than warm.  In summer at temps of 27C/80F the unballasted 
was about 67C/152F and the ballasted was about 62C/144F.  If the electrical 
conditions don't change the temperature of a coil is solely dependant on 
ambient temperature - it has to be higher than the air around it in order to 
dissipate the energy that the electrical circuit is putting in to it.


----- Original Message ----- 

> Sometimes it's not just one thing, or even two things.

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