With SOHC heads and no more than 330 bhp, the Repco was by far the least powerful of the new 3 litre engines but unlike the others it was light, reliable and available right from the start of the new rules.
Copper je uporabil zastarele motorje Maserati V12, ki so bili narejeni za Maserati 250 F v poznih petdesetih letih, medtem ko se je BRM odločil za težek in zapleten motor H-16.