[AT] Questionable ignition coil

[James Peck]

Cecil Bearden AT list member, Oklahoma farmer, and Professional Engineer <crbearden at copper.net>;I have a couple of old Sun distributor testers.  I check coils with them.  You can tell if the problem is with cranking or high speed.  I had a 6cyl 292 chevy that would cut out above 2500 rpm.   I had checked all the valves,  rebuilt the carb, replaced the points etc.  I put a "new"rebuilt distributor on the sun machine, and found that the distributor shaft was worn and with the new bearing it had a clearance of nearly 0.010  At 2000 rpm it started to oscillate.  I took it apart and found that the distributor must have been in a watery junkyard for years.  I took apart 3 distributors and ended up building up the wear on one shaft, then building a bushing out of a piece of Nylatron.  Nylatron is a type of nylon that is impregnated with graphite.  I use it for a lot of bushings.  I bored the distributor out and replaced the top bushing with nylatron and the bottom one with brass.  By honing, I got the top of the shaft to 0.000 side movement, and the bottom with the gear to 0.005in...  Then I set it back up and tested the coil firing.  This time the coil worked fine up to 5000rpm until I set a hair dryer to warm up the coil.  With a infrared temp gauge at 140 deg, the coil would break down at 2000 rpm.  This time I tried an Accel Super Street/Strip  coil 45000V, it would fire a 1/2 inch blue spark up to 6000 rpm.  I installed the distributor and coil in my old winch truck, and it had twice the power as before.

Gilbert Schwartz AT List member and Allis Chalmers G owner <vschwartz1 at comcast.net>;I would like to try and delve into the wide knowledge and expertise of the members within ATIS. 
Is there any acceptable method of determining if an ignition coil is good short of installing it on a running engine. Our 1949 AC G would not start a few days ago after being parked for a short period of time. A quick observation determined the contact points were beyond use. I went to the local auto parts store and was advised I probably should replace both the points and of the condenser because they felt like that condenser went first and it caused the points to burn up. With this information I also purchased a new coil even though I wondered if the coil was a bad. 
Bottom line; Is there any way to bench test a coil? We have several used coils laying around here of questionable viability. I would like to pitch them if they aren't any good. 
I appreciate anything you can tell me.