What could cause a cam bearing to pop out of place?

Got a motor off a guy, a460 block btw. And one of the cam bearings was poped out of place, what could cause this.

Poor housing sizing, poor bearing sizing or someone trying to reinstall a used one, improper clearancing to the camshaft can screw them out or spin them, poor tunnel alignment has been know to cause issues and also a bent cam could cause issues.

Popped out or spun out? Was the bearing bore scored?

Thanks for the input guys
And that's a good question il go to my garage tonight and check the bore

Usually ... not enough press or not enough clearance or a little of both.

There is sum slight scoring in the bearing bore

Only 1? Where the the factory installed ones in the block?

Yes only 1, and I'm not sure if it was the factory ones

Is there any scoring/damage on the edges, did you remove the cam or someone else?

I've seen a #5 roller bearing 'fall' out of an alum. A96 block......1st suspect was reusing the bearings.

Cam was already out.
Il jus send block and cam to engine and have him check things and put new bearings in and cam in.
Thanks again guys

Lem Evans wrote:I've seen a #5 roller bearing 'fall' out of an alum. A96 block......1st suspect was reusing the bearings.

And you witnessed #5 falling out of a Dove-a block too.....

dfree383 wrote:

Lem Evans wrote:I've seen a #5 roller bearing 'fall' out of an alum. A96 block......1st suspect was reusing the bearings.

And you witnessed #5 falling out of a Dove-a block too.....

I do not like to mention all the shit I've seen

Lem Evans wrote:

I do not like to mention all the shit I've seen

And we thank you!