any one a machinist or have a thurough understanding of 4G63

I've been meaning to write this up for a while, but keep forgetting. Maybe it is a stupid question, but...
On the #4 cylander, inside the combustion chamber, on the exhaust side, there is a galley or port that seems to be an oil squirter or coolant squirter. Does anyone what this is and it's primary function???
Any help understanding this would be greatly appreciated.

 

[grocery_getter]

That's the port for egr. It snakes in the head and resurfaces on the intake side of the head.

 

thank you, i'm oblivious, that is where the water was pooring out when I was testing the valves and i didn't even think of that.

If the EGR is blocked off, would it make any sense to fill that in??? (Not thinking of doing, just wondering)

 

[grocery_getter]

Just leave it alone. No sense creating extra work for nothing.

 

thanks