XR8's cast-iron 5.0-litre pushrod V8 produces 220kW at 5250rpm, and 435Nm of torque at 4000rpm. The imported engine is stripped down to a short block by Tickford, then fitted with a new camshaft, new cylinder-heads with improved breathing, larger stainless steel valves and springs and opened-up ports. The combustion chamber is machined for improved airflow and the heads are shaved to achieve a 9.4:1 compression ratio. The coupe de grace is the fitment of the low friction roller-rockers that allow the engine to rev higher. Further work is done on the upper and lower intake manifolds - the former to allow fitment of a special Tickford designed 70mm throttle body. A recalibrated fuel regulator increases fuel pressure. As a final embellishment, each engine is personally engraved by the builder. The XR8 also gets a special low backpressure high flow exhaust manifold. The 220kW engine requires the use of premium unleaded fuel.