The traditional method of modifying cylinder heads by hand fettling was superseded some years ago with the advent of CNC (Computer Numerically Controlled) machinery and CAD-CAM (Computer Aided Design – Computer Aided Manufacture) techniques. However, this has been the preserve of the better funded professional engine companies such as Ilmor Engineering and Cosworth simply because the machinery, software and resources have been beyond the reach of smaller operations
Our heads have – the latest Port Designs – and unique machining techniques which enables the creation and production of complicated 3D geometry to be developed efficiently and cost effectively. This, together with a state-of-the-art air flow rig and a great deal of engine development experience has made it possible for AP RACING ENGINES to offer superior, CNC modified cylinder heads that comfortably outperform any other comparable cylinder head on the market today, SEE OUR FLOW CHARTS FOR TRUE PEFORMANCE DATA.
CNC Valve Seats
The valve seats are an extremely important feature of any cylinder head. The quality and precision of the valve seat geometry determines how well the valves seal against gas pressure, how fast heat is transferred away from the valve heads and the rate at which the mating faces will wear in service.
Apart form these thermo-mechanical factors what is also significant in a high performance engine is the influence of the seat geometry on gas flow behavior in what is a critical area for the gas exchange processes. Continuous development using air flow rigs and engine dynamometers has shown that real gains can be achieved by paying careful attention to this area.
It has been found that conventional 3-angle seat cutting machines have limitations in terms of cutting suitable profiles for performance as well as in the quality and consistency of the valve seats so produced. This is particularly true when fitting new, hardened, oversized valve seat inserts for big valve conversions.