8BA timing jumps a few degress
 

Noticed that my initial timing set on the 'bump' moves occasionally, a few degrees advance. The distributor is a Mallory dual points, with 600 miles use, so the distributor gear is not worn. Usually it stays right on the bump. Normal or??
thanks.

Re: 8BA timing jumps a few degress
 

I would call it "normal" for an engine with clearance between the cam thrust faces and the block/front cover. For a full explanation you can read my book but the general epitome is the spiral gears change the timing as forward and rearward movement occurs.

Re: 8BA timing jumps a few degress
 

I agree. Aftermarket electronic ignitions are almost always troublesome. As the ignition systems on old Fords of any vintage are "bulletproof" , if properly set up, I put them in the category of "if it ain't broke...."

Re: 8BA timing jumps a few degress
 

I picked up one of the old Mallory 8BA two part cap dist one time to use on my 59AB, I got the adapter to bolt on the front of the cam to drive the dist. Set the timing and it run fine until I rev it up fast and the timing would go out about 20*, reset the timing and the same thing happened again, I pulled the front cover and the small gear that drives the dist was slipping. I removed the gear and knurled the adapter and pressed the gear back on, never happeded again. Walt