back lash 31 a
- Thread starter lenmissy
- Start date
Purdy Swoft
Well-known member
The amount of backlash in the distributor will depend on the amount of wear in the ends of the intermediate distributor shaft, distributor and oil pump drive gear and the amount of wear on the center camshaft gear teeth. In many cases the backlash will be one half inch or more.
The timing can be adjusted to move the backlash to the counterclockwise side so that it doesn't effect the timing. Here is what I do for a quick and fairly easy fix. I first set the points at .022 . I then remove the sparkplugs to remove compression resistance. Remove and reverse the timing pin. Turn the engine over with the hand crank until the timing pin falls into the indentation on the cam gear. Loosen the screw that holds the points cam and adjust the points cam so that the trailing edge of the rotor tip points at the number one contact in the distributor cap body with NO clockwise backlash. It will probably take a few tries to get the cam tighened so that it points correctly after tightening. In other words all backlash will need to be in the counter clockwise direction after tightening of the cam so as not to effect the timing. That is really all that there is to it. Try it, what do you have to loose? If you set the timing exactly the way that I describe you should, unless you have other problems, then have good power and throttle response. The car should then run good at speed with the spark fully advanced and you can retard the spark as necessary for low speed and to control timing knock if in a strain. With this method you don't need to be concerned with the time of points opening or the position of the spark lever. Unless the points cam was incorrectly manufactured the points will be opening at the correct time, if you followed my instructions. Also while the spark plugs are out you may as well clean and set the gap at .035. I always polish the plug wire straps with some steel wool or such to improve conduction. Try this and let me know, you will be surprised. I run all of mine this way and they are purdy swoft. Good luck.
Purdy Swoft
Well-known member
The distributor turns counterclockwise when the engine is running . As the engine turns you should be able to see this with the distributor cap off. The brass tip of the rotor is probably 1/2 inch wide. the trailing edge of this brass tip as the engine turns needs to align with the number one contact in the distributor cap body. when the screw that holds the distributor cam to the distributor shaft is tightened, there needs to be NO clockwise backlash or rotation. In other words when the timing is set the TRAILING edge of the rotor tip should point at the number one contact in the cap body with NO clockwise backlash or rotation. I usually don't try to explain this anymore because people without mechanical model A experience have a hard time understanding. If you can grasp what I am trying to explain you will be amazed at how good your car will run.
Purdy Swoft
Well-known member
Sorry about all the rambling. The back edge of the rotor tip needs to point at the number one contact in the distributor cap body. Good luck and let me know how it works out.
1931 flamingo
Well-known member
There's a new tool out that most vendors now carry for setting dist cam. You find the timing pin mark, loosen cam screw, install tool, rotate two turns clockwise til end of tool hits #4 pin on dist cap, tighten screw, points just starting to open, removes all slack(wear ) in the shafts. Love it.
Paul in CT about $10
Paul in CT about $10
Purdy Swoft
Well-known member
There is no need for you to worry about when it fires. If you have the trailing edge of rotor tip pointing exactly at the number one contact in the distributor cap body with no clockwise backlash when the timing pin drops into the indentation of the timing gear you will be good to go.