How is the S70 engine different from the M70 V12 upon which it is based?
When creating the 850CSi’s S70 V12 motor, BMW Motorsport began with the standard 24-valve SOHC M70 engine and instituted the following changes: -Increased bore (from 85mm to 86mm) and stroke (from 79mm to 80mm) for a new total displacement of 5,576cc (from 4,988cc) -Lighter pistons -Increased compression (from 8.8:1 to 9.8:1) -More aggressive valve timing for increased high-rpm power -Larger diameter exhaust pipes -Variable rpm limit (6,400 in 1st+2nd, 6,200 in 3rd, 6,100 in 4th. 6,000 in 5th+6th) -Adjustable throttle sensitivity via dual mode (Sport or Komfort) console-mounted switch -Engine oil cooler (European-spec models only) These modifications resulted in an increase in maximum power from 300 hp (DIN) or 296 hp (SAE) at 5,200 rpm to 380 hp (DIN) or 372 hp (SAE) at 5,300 rpm. In addition, maximum torque was increased from 332 lb/ft at 4,100 rpm to 402 lb/ft at 4,000 rpm. This engine can be identified by the “Powered by M” inscription on the central cam cover between the two banks
