Whoops!!
 

I just wanted to hear what the worst mistake any of you have ever made when rebuilding a motor. A couple of weeks ago , I made a horrible oops on a customers truck ( thank god this was not a p car), and I was hoping some of you could make me feel better with some of your own horror stories.
Thanks

I'm not proud.....

hooked the oil lines up to the wrong in/out on a remote oil filter on a freshly built formula vee engine and proceeded to roach it during the first practice session. Again, thank goodness it wasn't a Porsche engine....

but to my defense, the oil filter adapter was marked incorrectly.

Dion

I broke the corner off a compression ring and didn't discover it until the engine started burning oil. Ruined the cylinder.

-Andy