Drilling coolant passages on heads

[ranger1911]

Hi folks,

I remember reading somewhere that the heads develop a hot spot between two cylinders which can be solved by drilling out an additional coolant passage, but I can't seem to find the article which describes this process. I am doing an engine reseal and would like to do this while I have the heads off.

Does anyone have a link handy, or have the information? I believe the head gaskets have the correct hole in them already but I don't remember the correct depth to drill.

Thanks!

 

[SenorNoob]

"Performance Upgrades:

Cylinder Heads:​

Cooling - A simple upgrade to the 2.8L heads is to drill two more water passages in them between where the two exhaust valves are side by side. This helps prevent a local boiling point from forming. Just use a good head gasket that already has the water passage holes in them for a guide, and mark the head and drill two holes. Keep the holes a little smaller than the holes in the head gasket. - Contributed By Ryan Propst"

Ford 2.8L Engines

 

[ranger1911]

Sounds simple enough. Thanks for the info!

 

[fergusonic]

I cut a bad head into to see what the water passages looked like and at what depth one has to drill. Head bolt goes where my finger is on gasket. note the hole on the left (Red Arrow) is only partially thru due to casting. I think I used a 1/4" drill bit. Have fun.

 

[ford4wd08]

I cut a bad head into to see what the water passages looked like and at what depth one has to drill. Head bolt goes where my finger is on gasket. note the hole on the left (Red Arrow) is only partially thru due to casting. I think I used a 1/4" drill bit. Have fun.View attachment 52260

@Jim Oaks

This should be added to the 2.8 page in my opinion. Great picture.