Now compare that to the Twisted Wedge combustion chamber. The intake valve has been moved to the opposite side of the chamber and is now oriented so that air flowing through the intake port has a straighter path into the cylinder. The new chamber design also allows for a large 1.840-inch intake valve without requiring a new piston or boring the cylinders. The exhaust valve is 1.450 inches. Finally, Trick Flow offers this head with two different combustion chamber sizes. This is the smaller 38 cc chamber, but if you plan to add a turbo or supercharger, you may want to consider the 44cc chambers.