Re: Removing distributor

Posted by HH56 On 2021/9/26 10:41:46

The slot on the left of the flange was typically used by a non mechanic type for a slight octane adjust that was sometimes needed back in the day when fuel supply with a constant octane was not as reliable. It probably won't need to be touched today.

Basic timing was adjusted by the mechanic with the scale at the slot set to the middle and locked. The clamp screw under the distributor body is then loosened to rotate the entire distributor in the flange to set the base timing using the necessary test equipment. When the specified timing was obtained the distributor body was clamped tight in the flange at the desired setting.

Once the base timing was adjusted a driver or service station guy could then play with the limited adjustment available via the slot to fine tune the timing a few degrees in either direction. It would be set to run best on the fuel being used if it happened to be different enough from the last tankful to ping or whatever. That adjustment was done more by sound and performance rather than needing special equipment.

Because the slot limits the amount of change and has a scale you can refer to in case you wanted to go back to a former setting, it is not very easy to get the timing so far out of spec the engine wouldn't run. That issue could easily happen if someone tried to rotate the distributor body a tiny amount only to have it suddenly break free and overshoot where you wanted it and no way to know precisely where to go back to the former position.