cam bearing failure

[steel town]

I know another bearing question .I just finished reading threw the other threads to see if you guy's have answered this question already .I just pulled my pan off and I could see a small piece of what looked like flashing my first thought was that my bearing was beaten but when I pulled the engine down it looked more like the bearing had started to fatigue and fall apart (seperating) .I've never had any oil problem but I did notice the bearing hole was siting at the bottom . I know for a fact it wasn't there when it was installed .This past summer my fan belt came off at the track and I didn't notice . The engine got very hot . I was thinking that the cam may have grabbed the bearing and turned it a bit and may have started this bearing failure . So what do you think is the hole at the bottom possibly another problem not giving the cam proper oil and adding to the bearing failure ???

P.S it's a 406 with a small base circle cam the cam was checked with a dial indicator befor installing it 2 years ago

[Jay Allen]

For a cam bearing to fail there is only a few things it could have been.

1. Lack of oil. This could have been caused by a multitude of things.
2. Harmonics. And a small base circle cam that is NOT controlled properly will screw some good parts up in a hurry. Like excessive (fan blowed up) and the heat killed the valve springs. It won't take long to break something.

[steel town]

Thanks Jay I think your onto something .I run a gear drive and I was questioning if it had a roll to play in this problem .I've heard they cause Harmonics .