Seeing as we're not going to be racing our Mini anymore we decided to do something useful with it. Since we have the know-how and all the tools necessary to design and machine a cylinder head we decided to create one from scratch. The head is designed for a 998cc A-series engine and features 8 ports with the center exhaust split. It will be a big improvement over the stock 5-port head.
The head will feature 33/29mm valves and because we slightly moved the valves it will not require pocketing of the block. It will also work with "normal" camshafts.
There are some similar designs already on the market, but they have often compromised the placement of the spark plugs in order to achieve 7/8 ports, and on top of that don't really produce that much hp over a ported stock head. They also don't offer any customization options for the customer, which we feel is one of the biggest advantages of CNC-machining each head from a solid piece of aluminum. Because each head is machined individually we can for example easily customize the combustion chamber volume, so that the desired compression ratio is achieved.
Below are some pictures of the manufacturing process of the first prototype. We first machined all the hole locations into a thick aluminum plate to double-check the location of everything and made some small changes(in the 0.1mm range) to ensure a perfect fit. We then machined the ports using various machining parameters to see which values work best. We now have a fairly good understanding of what works and what doesn't and will soon machine a new more refined piece that we will test in our racing Mini.