Buick 3.8 V6 Cylinder Heads

The power is in the heads. A motor is essentially an air pump. Getting the air to flow more efficiently is the secret to horsepower. A turbo increases the pressure differential so you move more air. Normally aspirated motors are limited to around 14.7 psi of pressure to force air into their cylinders. The turbo overcomes that limitation. Even with a turbo, air flow is still the issue. Porting the heads has a dramatic impact on performance. My motor has stock iron heads ported by Champion with larger intake and exhaust valves added.


Here's a view of the porting done inside the valve bowls.
 

Here's a view of inside the valve bowls of a stock head. Look at all the material around the valve stems inside the air passages. A lot of this is removed when porting.
 

Here's the intake side of a stock head. Note the amount of material between passages. This head still has the stock springs with the heat shields in place.
 

Here's a view of the intake side of the heads. Note the EGR passages are welded and filled for added strength. To take advantage of this you have to use a FelPro intake (valley) gasket and shave it to match the heads.
 

Here's a view of the exhaust side of the ported heads.
 

Here's the exhaust side of a stock head. Not a lot of difference until you notice the material around the valve stem. Check out the one on the right. You can see the stem is covered with a lot of material blocking the air flow. The valve stem is visible in the ported head above.
 

Here are the heads bolted on the motor before the lifters, pushrods and intake are installed.