There are many ways to modify a cylinder head for more power without changing to forced induction. Cylinder head porting is a much less drastic but worthwhile modification that could bring a few more horses to the stable.
There are many areas within the cylinder head that can be attended to:
• Exhaust Ports – material can be shaved especially from the top of each exhaust port, where the highest velocity air is found exiting the cylinder. Port matching with the exhaust manifold can also be conducted, making sure there is no change in diameter between either component which could cause a restriction otherwise
• Inlet Ports –relieve the port of ruts and unwanted metal from casting. Port matching also applies to the inlet manifold, making sure that it is a precise fit
• Valve Throat Pocket – possibly the most important area to have smoothed and widened, promoting the efficient movement of flow through the throat by smoothing off any edges and chamfers left by factory machining
• Valve Seat –this modification will make sure that the valves create an exact seal with the valve seat when closed, thus improving the volumetric efficiency of the engine
• Combustion Chamber – polishing of the area that makes up the top of the combustion chamber is conducive to efficient exhausting of the cylinder, with a polished finish allowing a smooth transition of the combusted air/fuel mixture out of the cylinder and into the exhaust manifold
To properly analyse and validate the job, a head should be tested first on an air flow bench which measures the volumetric flow rate (how much air is getting in and out of the head). This will give a base figure to compare to once the head has been fully ported and polished, leading directly to a gain in horsepower.
Using our air flow bench and porting facilities we can calculate the maximum potential horsepower your engine could produce. This information is also critical for correct camshaft selection.