with Ch. 7( Competitors Vehicles and Vehicle Safety Equipment) and to the extent relevant Ch. 8( Fuel and Tyres and Testing). All Vehicles competing in Road Rallies must comply with the appropriate part of the following:
11. Body
11.1. Bodywork must represent the manufacturer’ s original profile and may include any optional extras available directly from the manufacturer.
11.2. Bumpers must be fitted. 11.3. Paintwork must be one colour or manufacturer’ s original colour scheme. No primer is to be visible.
11.4. Vehicles must not have wheel arch extensions unless fitted by the manufacturer as a standard item to the body shape.
11.5. All major internal trim as fitted to the body type by its original manufacturer when offering it for sale must be retained. Major internal trim includes headlining, inside door panels( which may be replaced with representative material) for all doors and / or rear side panels alongside the rear seat( for a 2 door car), carpets and rear seats. It does not include parcel shelves, boot carpet or boot side trims.
11.6. Front seats may be improved or replaced. 11.7. The trim including the rear seat may be cut to allow the fitting of a safety cage.
11.8. If equipped with a non-standard fuel tank it must be separated from the Driver / Passenger compartment by a protective bulkhead of non-flammable material preventing the passage of fluid or flame.
11.9. Full harness seat belts may be fitted. 11.10. Guards may be fitted beneath the vehicle to provide protection from damage.
12. Engines and Transmissions 12.1. Vehicle engines must have:
a. A maximum of four cylinders. b. A maximum of two carburettor chokes( two single or one double). c. A maximum of one camshaft per bank of cylinders.
12.2. Engines with more than one camshaft per bank of cylinders may be used providing that:
a. Any replacement engine comprises a block and cylinder head from the same engine family. b. c. they were originally fitted with fuel injection and
that the fuel injection system complete with inlet manifold and throttle body is retained unmodified except as permitted in Art. 12.3. c below.
12.3. In respect of Art. 12.3. b above it is permitted to make the following modifications to effect installation:
a. Alternative engine mountings, sump pan and exhaust manifolds. b. Relocation of ancillaries such as alternators and steering pumps. c. To change the orientation of the otherwise unmodified inlet manifold.
12.4. For diesel and petrol engines under 1500cc actual capacity forced induction is permitted providing that the complete original induction system is retained unmodified other than the replacement of the air filter element.
12.5. Fuel injection may be fitted where it was standard equipment by the manufacturer for that engine type and where the original plenum chamber and throttle body is retained for that engine type.
12.6. A standard Wankel unit will be considered as three cylinders. Twin Wankel units are prohibited.
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 16 Part A( Autocross and Clubcross) Appendix 5- Technical Regulations
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