Welcome Visitor! Please take a few seconds and wagonerkl
Member
- Joined
- Feb 3, 2011
- Messages
- 16
- Transmission
- Automatic
Yes, I have already read the info in the tech section,
" 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"
When I asked for specifics on another web site, I got conflicting information, "drill four holes instead of two". I was trying to get amplifing information but no one here seems to have actually done it...now I have so I am considering myself the new "expert" on the procedure.
There are four holes in the new head gaskets. All four CAN be drilled but the forward two are more important because that is where the #1 cylinder and #2 cylinder valves are side by side in the head, which creates the "hot spot" in the head. Same is true on the left bank with #4 and #5. Everywhere else there is an intake valve adjacent to an exhaust valve so the exhaust gets some cooling effect from the intake valves cooler temp.
I laid the gasket over the head and center punched each hole location. Then I drilled a small pilot hole to one inch depth. I followed that with a 3/8" hole also to 1 inch depth. You really don't need 1 inch deep on the exhaust port side as you will cut into the water jacket at about 3/8" but you won't hurt anything at 1 inch deep. The holes on the intake port side cut into an internal casting rib so you are cutting metal the entire way down. The water jacket opens fore and aft as you drill through.
In short, mark holes on gasket and drill all four holes with 3/8" bit to 1" deep. Easy as pie. The block has water passages that line up perfecetly with the new ports in the head. Pictures to follow...
" 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"
When I asked for specifics on another web site, I got conflicting information, "drill four holes instead of two". I was trying to get amplifing information but no one here seems to have actually done it...now I have so I am considering myself the new "expert" on the procedure.
There are four holes in the new head gaskets. All four CAN be drilled but the forward two are more important because that is where the #1 cylinder and #2 cylinder valves are side by side in the head, which creates the "hot spot" in the head. Same is true on the left bank with #4 and #5. Everywhere else there is an intake valve adjacent to an exhaust valve so the exhaust gets some cooling effect from the intake valves cooler temp.
I laid the gasket over the head and center punched each hole location. Then I drilled a small pilot hole to one inch depth. I followed that with a 3/8" hole also to 1 inch depth. You really don't need 1 inch deep on the exhaust port side as you will cut into the water jacket at about 3/8" but you won't hurt anything at 1 inch deep. The holes on the intake port side cut into an internal casting rib so you are cutting metal the entire way down. The water jacket opens fore and aft as you drill through.
In short, mark holes on gasket and drill all four holes with 3/8" bit to 1" deep. Easy as pie. The block has water passages that line up perfecetly with the new ports in the head. Pictures to follow...
