I have put my Cobra away for the winter and last week I decide to pull the distributor since there has been so much talk about gear wear. I have a 351W with an MSD distributor, a Comp solid lifter cam, and a stock
oil pump. The engine has 1500 miles on it.
Well sure enough, the gear had quite a bit of wear. Each tooth is evenly worn, top to bottom. There is no sign of wear on the bottom of the gear similar to what Andy Dunn found or uneven wear as described by Todd at the beginning of this thread. I haven't tried to turn the
oil pump manually yet, but I will. I will also try to turn the
oil pump using the distributor once the gear has been removed from the shaft.
I took the distributor to the engine builder on Friday and he simply shook his head. He couldn't believe it, another gear problem. He said that he rarely saw distributor gear problems until a year or two ago, now they are very common. He has contacted a couple of other engine builders and they are also seeing the same thing.
He took various measurments, turned the shaft, etc. He said that he cannot see anything out of the ordinary. He is going to replace the gear. The one thing that he did mention is that he will put a good amount of "cam break-in lub" on the distributor gear before it goes back into the engine.
Wayne