Careful with that camshaft

[XfireZ51]

Busy w “refurbing” the motor this winter. Pete has it and in process of swapping over components to a different short block. During disassembly of the valvetrain Pete loosened the timing gear bolt on the snout, a pretty typical procedure for refurb.
The camshaft snapped into 2 pieces as he applied the necessary torque to loosen the bolt. (See attached). In all the years Pete has been doing this, nothing like it has ever happened. So I decided to ask Marc, given his vast experience, whether he has an experience with a cam breaking that way. Marc said he had never seen that before, but also offered a tip on this procedure. I asked if I could post for the rest of the community and he kindly agreed.

Here is his response:

Hi Dominic,
>
> We have not had that happen. Long ago I would hold the back end of the cam and loosen the cam sprocket bolt. I guess I got lucky and never broke anything. I became concerned about the stress along the cam. For the past ten years or so we let the chain take the load. After removing the cam cover the first thing that we do is loosen the sprocket bolt without holding the cam. This way the torque does not go down the shaft of the cam.
>
> Maybe you found a cracked or weak cam the safe way rather than at 7000 rpm.
>
> Best regards.
>
> Marc

The camshaft of course was never designed to take that type of twisting, and as our components get older, they become more frail just like we do. 😉🤣

So just thought I’d pass along some words of wisdom.