the more robust engine cylinder head

[Dave]

Whatever you do to them you just cannot pull the heat away from the pre-cups, there is just no win situation, unless you had bigger water pump, open up the galleys and thinner wall material to pull heat away quicker, they just heat up so quickly with serious boost/power.

Imagine 150kW and the only delivery of this energy is through the tiny pre-cup hole which is like 7mm or something, it soon heats up beyond what you can pull from it.