CBN55-6002 – N55 Stage 2 High Performance Engine

The stock engine compression ratio is relatively high due to the Corporate Average Fuel Economy (CAFE) standards which push for consistently higher fuel economy in cars and trucks. However, this increased compression limits engine performance with higher boost settings by decreasing the size of the fuel-air charge in the combustion chamber, forcing the ignition timing to retard far below MBT (mean best timing, the theoretical optimal ignition timing). Therefore, the Carbahn N55 engine has 0.5 less compression to optimize the engine for the increased boost. 

The CarBahn engine is both stronger and less expensive than the BMW OEM factory engine. The N55 CarBahn engine is designed to improve the strength of your engine if you are tuning your car. Connecting rods are replaced with Carrillo forged racing rods, pistons are CP forged racing pistons, CarBahn Pined crankshaft, full circle thrust main bearing and performance valve springs for increased boost pressure. The engine is a complete overhaul with blue printing and balancing.  This engine is designed for an increase in torque of 100% over stock

The N55 engine is not designed to take a large increase in boost beyond the OEM spec. Due to the design of the crankshaft, it is known to have the timing chain sprocket spin on the end of the crankshaft, causing the cams to go out of time. In extreme cases, the valves can hit the pistons, causing catastrophic damage. Furthermore, the N55 only has half of a normal crankshaft thrust bearing. To ensure durability we pin the timing chain sprocket to the crankshaft, machine the block to accommodate a full circle thrust main.

CarBahn History

Steve Dinan’s engine shop has been building high performance and racing engines for BMW s since 1977, winning 12 racing championships including 3 prototype championships and two 24 Hours of Daytona. The same engine shop that builds the racing engines also builds the street car engines; these talented engineers, machinists, and builders have built hundreds of engines from OEM street rebuilds to full-blown racing engines.You will not find a higher quality engine. All engines are backed with a two-year warranty.

Engine core acceptance parameters

Must be complete core (factory engine, from oil pan to valve cover)

• Block must have no:
  • Holes or cracks in casting
  • Holes or crack in covers
  • Bore damage that cannot be honed out
  • Thrust surface damage
  • Journal surfaces damage
  • Bolt hole damage that can’t be repaired
• Heads must have no:
  • Holes or cracks in casting
  • Holes or crack in covers
  • Thrust surface damage
  • Journal surfaces damage
  • Bolt hole damage that can’t be repaired
• Additional repair charges could apply for damaged items that are not normally changed during an overhaul and cannot be repaired or serviced
  • Valves
  • Crankshafts
  • Camshafts
  • Guides
  • ValveTronic mechanism
  • Vanos mechanism