Cylinder Head
Info provided by Calvin of the Nivlac57 YouTube Channel and Marc of EmTech Motorsports
Stock Valve Sizes
Intake
Exhaust
Difference
Head Porting
These engines have great flowing intakes ports, and pretty poor flowing exhaust ports. The reason this was done was to make room for more cooling capacity due to the higher compression ratio of these engines. In 06, the heads received larger valves and larger exhaust ports, but they could still use some help. Here are some pictures of what the ports look like before and after porting.Â
When running non-stock cam shafts the exh. side oil boss must be clearanced for the cam follower. The area in black needs to be removed. You need to mock up your cam and check the amount of material to remove. Be careful not to cut into the oil passage.
Complements of Emtech