What to look for
There’s one golden rule: make sure it’s an authentic RS500. You wouldn’t be the first to buy a fake made from a regular RS Cosworth ( or worse still, a base-spec Sierra), and you need to be aware there are still some ringers ( and even some duplicates) kicking around.
A proper RS500’s chassis number ( found on the logbook, slam panel-mounted VIN plate, and stamped into the floor under a flap beside the driver’s seat) will range between WFOEXXGBBE38600 and WFOEXXGBBE39099. Bear in mind that an RS500’s engine number will not correspond with the VIN, and instead refers to the YBB of the regular three- door Cosworth on which it was based. Genuine RS500 numbers ( stamped onto the front of the crankcase above the water pump) were YBD0015 to YBD0537.
Before even looking for an RS500 – it’s essential to contact the RS Owners’ Club ( RSOC) and speak to the RS500 registrar. The RSOC holds a list of RS500s, including chassis numbers and engine numbers.
If you’re paying serious cash for an RS500, it’s crucial that the numbers tally with what’s on file – a car lacking its original engine will be worth several thousand less than a ‘matching numbers’ example. The engine itself should comprise a thick-wall cylinder block with smaller core plugs than a YBB (7/8in diameter) and a reduced-size 205 cast onto the right-hand side just below the cylinder head. Look, too, for an 8-injector inlet manifold and extra fuel rail ( with battery tray chopped to fit), larger throttle body, unique alternator adjuster, map sensor bracket and turbo damper.
All genuine RS500s were righthand drive shells with glass sunroofs, distinctive extra rear trailing arm mounts, electric aerial in the offside rear wing, revised front bumper ( with enlarged air intake and vents in place of fog lamps), larger whale tail with additional 30mm lip and additional lower rear spoiler ( similar to but subtly different from a Sierra 2.0iS part).
Finally, don’t panic if there’s no build-number plaque on the dashboard – they weren’t factory-fitted.