BriSCA F2 and the SSCA have received requests from a number of engine-builders and drivers to allow the shimming of ‘relaxed’ valve springs in the 2.0-litre Ford Zetec engine, when undertaking rebuilds, in response to the unavailability of new standard Ford items. BriSCA F2 and the SSCA have reviewed the proposals and will implement the following change with immediate effect.

A spacer shim, to be fitted underneath the valve-stem oil seal, will be permitted, subject to the following:

• The spacer shim must NOT be thicker than a MAXIMUM of 0.050” (1.27mm). Note, there is NO tolerance on a maximum thickness.
• The shim MUST be made of mild steel, such that it is magnetic.
• The shim MUST be fitted underneath the valve-stem oil-seal, between the oil-seal and the cylinder head.
• The shim MUST be a loose fit in the oil-seal/valve-spring recess, such that it can simply be removed by way of a small magnet without the need for any other tools.
• The shim must sit flat against the base of the oil-seal/valve-spring recess in the cylinder head. The use of a tight-fitting shim that sits off the base of the recess due to interference with the valve-guide or outer wall of the recess is NOT permitted.