Re: Henry's 55 Constellation

Posted by John On 2008/3/4 13:41:08

I agree with your dad that any coil should work, to some degree, especially just to get it running. But, the ingnition system usually is designed with a certain "balance" between the engine compression, plug type, fuel type, and coil discharge. As you can figure, a higher compression engine would need a stronger spark to ignite the fuel/air mixture, ergo a richer fuel/air mixture would also require a hotter spark.
Have you checked to see if you have the correct rotor in the distributor? If you are getting spark from the center of the coil, the problem could be in the cap or rotor.
I personally would perform the following checks in order:
1. Good battery
2. Points properly gapped and condenser connected
3. Coil properly wired
4. Insert long spark plug wire into center tap of coil
5. Insert spark plug (properly gapped) in other end of wire
6. Make sure spark plug is making contact with engine ground
7. Spin motor with starter

You should see spark at the plug gap, if not try holding wire close to ground while spinning motor. If still no spark, then I would consider the coil to be bad.

The above tests should take no more than 5 minutes, and I have found through years of experience that it is usually the little things that mess you up; such as reversed wiring, poor connection, etc. Bear in mind also that these recommendations are based on the fact that you do have the basic electrical system wired in correct polarity. The coil output is generated by a collasping magnet field around the secondary windings caused by the points opening and removing the flow of current from the primary windings. I don't recall exactly what will happen if the coil is wired backwards, but I do seem to remember a severely reduced output.
John