750 Trials' Formula

At a recent meeting the 750 Motor Club revised their 750 Trials’ Formula to bring it into line with the R.A.C. Formula. This means that an Austin Seven-based Trials’ car can now be built, which is eligible to compete in open events instead of the few events which were previously open to them. The Committee hope that a number of Austin-based trials “specials” will now be constructed. The new Formula is as follows:

1. The car, its chassis, bodywork and tyres must comply with the Road Traffic Acts, and current R.A.C. Regulations for Trials and Rallies, as laid down in the R.A.C. Motor Sport Handbook, obtainable from the Competitions Department of the R.A.C., Pall Mall. London. S.W.1, at 2s. 6d.

2. The following parts must be from the standard range of sports and touring Austin Seven components (pre-1945). Pattern parts will be accepted for replacement items.

Cylinder block, crankcase, gearbox, rear axle complete and main chassis side members which must be used as such. Rear springs must be ¼-elliptical. In addition the Big Seven rear axle may be used.

3. The engine must have a stroke of 3 in. and a bore not exceeding 2.28 in. (.080 oversize permitted). Overhead valves and superchargers are barred. Inlet and exhaust ports must not be reversed in function, nor must the siamised inlet ports be divided. The oversize inlet valve conversion now generally available is allowed. Any type of front suspension and steering is permitted subject to safety requirements. One gearbox only may be fitted and used.

4. This formula is devised for the benefit of the amateur constructor-tuner with limited resources. The 750 M.C. Board of Directors reserve the right at all times to reject any car which they feel represents an attempt to defeat the spirit of the regulations, even though it complies with the letter of them.

Note—Early type of Austin Seven wire wheel hubs with a solid centre (i.e. without a plated lush centre) are only acceptable if they are secured by stout plain washers at least 1 in. in diameter with suitable proprietary lockouts, such as Simmonds, Pinnacle. or Philidas, on the normal wheel studs.