It's important that every time a crew chief changes cylinder heads between rounds, he can be confident that each set is identical to the set he's taking off and that there are no variances. Building a better head Johnson is in the midst of the design and production of the company's newest Stage III billet-aluminum cylinder head. I to the Stage II heads. The new heads, however, will reflect some considerable design changes that should be evident after the teams test before the new season begins. The Stage III heads are being manufactured around the clock to meet the heavy demand of race teams stocking up for the 2001 season, most of which will begin test sessions in January with the new heads.
Computers are a big part of the cylinder-head business.
The normal turnaround time for this process is about four weeks. Johnson first introduced CNC porting of drag racing heads to gain the attention of crew chiefs throughout the industry. This process is one of the biggest gains in consistency for the crew chief working on a fuel engine. First, the CNC machine cuts the deck and drills the bolt holes. Then it is flipped over and the top side is machined.