Ahead of the 2025 World Final a couple of drivers have asked BriSCA F2 for a clarification on the camshaft timing regulations. BriSCA F2 feels it is important to share this information with all drivers rather than simply answer the drivers who have asked the question.

Regardless of the method used to time up the camshafts, the specified timing bar MUST be able to fit in to the slots at the rear of BOTH camshafts at the same time, as per regulation 231.13.17. The camshafts must NOT be timed independently of each other such that the timing bar will not fit in both camshafts' slots simultaneously.

Although regulation 231.13.17 states this must be at TDC, a maximum tolerance of +/- 0.010”/0.254mm (advance or retard) from the pistons’ position at TDC is permitted, as per regulation 231.13.16… provided that the specified timing bar still fits in to the rear slots simultaneously, i.e. BOTH camshafts are slightly advanced or slightly retarded together within the specified tolerance.

No driver has fallen foul of this check at championship events or any other meetings so far in 2025, and it must be stressed that this was simply a query from a couple of drivers seeking to ensure they are in compliance with the regulations ahead of the World Final weekend.