Ignition Tip from Jerry Robinette
By: Andy Wiedeman
Member of the Rocky Mountain A’s of
June, 2010
Last week when Bev and I were coming home from a short tour to Monument for dinner in my Model A it suddenly just quit running. I was doing about 50 mph at the time. Just no spark at all. After coasting to a stop, I lifted the hood, removed the distributor cap, rotor, and body, and inspected the points. They were stuck shut. A quick poke with the end of a screwdriver got them working again, and I got home afterward without incident.
The points in the distributor are modern V8 points and were replaced last summer. There are less than 150 miles on them. An inspection the next day showed the point gap had gone down from the set point of 0.018 of last summer to 0.012 after less than 150 miles. A further inspection with a magnifying glass showed no deterioration of the surfaces of the points. It is possible that the spark across the points on opening, with the small gap, temporarily welded the points shut, however there was no obvious evidence of it. Les Andrews at page 1-104 in his famous book claims with modern V8 points that “The cam contact block is nylon and offers little or no wear”. Obviously in my case this was not true.
A discussion with Jerry Robinette concluded that it is not unusual for a NEW point set to wear rapidly during the first 50 miles or so, then seem to settle in and not wear down the cam follower block at the same rate after the first 50 or so miles.
While this does not totally answer the question of why they stuck shut, it is surely something to check after installing a new set of points. After about 50 miles or so be sure to recheck the point gap and reset them if necessary, and put another blob of grease on the cam!
Keep your radiator full … Andy