Cracked Engine Block

Unfortunately we found a crack on our Eliminator Race Block today. It’s on main bearing #3, outer bolt.

Does anyone have experienced that as well?
Can this be fixed? Laser welded?!

Welding changes the properties of the cast iron making it brittle and thereby even more prone to cracking, especially in a load-bearing location such as you have.  The change in the cast iron's properties from the welding is known as "graphitization."

You are better off stitching it with a Castmaster-style thread insert from Lock-n-Stitch.  That type of repair will be stronger than the original cast iron, even with the crack still being there untouched.  I would suggest their "Full Torque Flush Blind" inserts, but really you should contact them directly with the same picture you posted here, including the thread size and the width of the main webbing at that location, and ask for their recommendation.

http://www.locknstitch.com/index.html