I have pulled the heads on my daughter's '84 Bronco II due to coolant in the oil. It appears to be nothing more than a blown head gasket. One of the Ranger websites recommends drilling additonal holes in the head to improve cooling. Has anyone done this and what are the specifics? Here is a quote from that site,

"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."

Any opinions on exactly how this should be done...or IF it should be done? Thanks you.

 

I did that very thing on a hi-pro 2.8 last winter. I had 2.9 valves installed and a new grind on the cam so I wanted all the cooling I could get, pouring gas from a 4 bbl into it will tend to generate more heat.
Just use a 1/4" drill after you mark the heads with the new head gaskets... between the exhaust valves... stick the gaskets in place or dowl them so they won't move. Just go deep enough to get into the cooling passage it's not hard to do. I do have a book on the 2.8 modifications by sven pruett if you are interested, I paid $100.00 for it but will let it go for $50.00 I got all I need from it and will pass it on at a better price for those who need it.
Joe

 

I just wanted to make sure you know, 4 holes around the center cylinder 2 top 2 bottom. And you can go out to 5/16 " aprox 1" deep.. This is straight from the book.
Joe

 

I just wanted to make sure you know, 4 holes around the center cylinder 2 top 2 bottom. And you can go out to 5/16 " aprox 1" deep.. This is straight from the book.
I have over 200 miles on it and no over heating!
Joe

 

Still got the book? I want to tune a 2.8, hopefully stroke it.

 

Sorry, sold the book on creigslist.
Joe

 

Joe,
I am at it again with another 2.8L . I never modded the first because I got confused by what you meant by "two up, two down". There are a total of four "extra" holes in the head gasket around the center combustion chamber in the head. The forward set of two are between the exhaust valves of #1 and #2 cylinders (talking right side of the engine in this case). The rear set of two is between the intake valve of #2 cylinder and the exhaust valve of #3 cylinder. Do all four get drilled, or just the ones between exhaust valves (the front two)?

I hope I explained it so you can understand. Thanks.