Washington, D.C. Centre
the Spark

Distributor Basics

by Dave Michel


How many times have you completed a tune-up of your MG (adjusted valves and timing, synched carbs, adjusted idle, etc.) only to find that your car just doesn't want to run like you think it should? Perhaps you have been perplexed by the less than sparkling performance of your MG on more than one occasion. Such a circumstance will be extremely annoying when, after a "complete" engine rebuild, your engine performs in a lackluster manner upon reinstallation, despite virtually all "adjustments" being spot-on. If you have found yourself in any of these situations, perhaps you need to examine the state of your DISTRIBUTOR.

The reason is that, despite the regular replacement of points and condenser, your distributor may have received little or no other attention, including lubrication, heretofore during its lifetime. The lack of any lubrication is a primary contributor to the wear of the bushings which support the load on the distributor and maintain the rotation in a circular path. Although this wear may not be obvious when the distributor is rotated at low speeds, or when rotated by hand when the distributor has been removed from the car, it may be significant at engine speeds of 500 to 3500 rpm! In fact, bushing wear, at over ~50,000 miles, may result in your distributor rotating in an ELLIPTICAL, rather than a circular, path. This elliptical rotation may contribute to erratic ignition timing and to exceptionally poor engine performance.

Fortunately, the fix is quite simple as distributors are easily reparable. The repairs may be accomplished either by depositing the distributor with a qualified repair facility which will perform the rebuild or to do the work yourself by following the procedures outlined in the various repair manuals. Once the rebuild has been completed and the distributor has been reinstalled in your engine, including resetting the timing, the change in performance may be dramatic, if not phenomenal! Try it, you'll certainly like it!!


Back to Technical Tips