Overheating on run stand

Agree with RRR. More timing on an unloaded engine. Engine is NOT driving the car, just itself.

Other thoughts:
- there will always be some air trapped in the cooling system of new engines. You have to run the engine, let the engine cool, to push the air out. This may take 2-3 cycles. The engine may run a few degrees hotter until all the air is out.
- if all new pistons, rings etc, it WILL run a little hotter.
- unless you have a special water pump that has NO bypass, there is no need to drill the stat, which will cause longer warm up time & no other benefit.