Description
The CarBahn Performance Pinned Crank Hub Kit is engineered specifically for the BMW S55 engine to help prevent the timing gear from slipping and rotating independently from the crankshaft. Designed for high-performance BMW applications, this crank hub solution addresses a known weakness of the factory crank hub design and provides a more secure connection between the timing system and crankshaft.
The factory crank hub design can allow the timing gear to rotate independently from the crankshaft. When this occurs, the engine timing can become incorrect, potentially requiring the engine to be re-timed. In severe cases, incorrect timing can result in piston-to-valve contact, potentially causing significant engine damage and requiring a complete engine overhaul.
The CarBahn Crank Hub Kit features a unique two-pin locking design similar in function to a crankshaft keyway. Unlike many aftermarket crank hub solutions that use multiple pins operating in shear, the CarBahn pins are designed not to operate in shear and are engineered to avoid the oscillation-related stresses associated with conventional crank pin designs.
CarBahn's crank hub design has been used in CarBahn High Performance Engines and, previously, in street and race engine applications since 2010, with no reported failures according to the manufacturer.
Many aftermarket crank hubs use multiple pins that operate in shear. During the major and minor harmonics produced by an internal combustion engine, the crank hub can oscillate and place excessive loads on these shear pins. Over time, this loading can contribute to pin damage and eventual failure. The CarBahn design was developed from extensive BMW performance-engine experience, including Steve Dinan's more than 40 years of BMW race-engine building experience.
The CarBahn Crank Hub Kit also uses modified BMW OEM sprockets. Retaining the OEM BMW sprocket design and metallurgical properties helps maintain durability characteristics comparable to the original BMW components while providing the additional crank hub retention provided by the CarBahn pinned design.
Product Features
- Engineered specifically for the BMW S55 engine
- Designed to help prevent timing gear movement relative to the crankshaft
- Unique two-pin locking design
- Pins are designed not to operate in shear
- Similar locking concept to a crankshaft keyway
- Designed to reduce issues associated with crank hub oscillation
- Uses modified BMW OEM sprockets
- Retains the metallurgical properties of the OEM BMW sprocket components
- Designed to maintain OEM-level component durability characteristics
- Developed from extensive BMW performance-engine experience
- Used in street and race engine applications since 2010 according to CarBahn
- Suitable for high-performance BMW S55 applications
Fitment
- Type: Engines & Engine Parts
- Vendor: CarBahn
- Make: BMW
- Model(s): M2 CS, M2 Competition, M3, M3 CS, M3 Competition, M4, M4 CS, M4 Competition, and M4 GTS
- Vehicle Year(s): 2015, 2016, 2017, 2018, 2019, 2020, and 2021
- Transmission(s): Automatic and Manual
- Chassis: F87, F80, F82, and F83
- Body Style(s): Coupe, Sedan, and Convertible
- Drivetrain(s): RWD
- Engine: S55
- Part Number: CBS55-6001
- SKU: CBS55-6001
- Installation Time: 18 hours
Applications
The CarBahn Performance Pinned Crank Hub Kit is designed for rear-wheel-drive BMW F87, F80, F82, and F83 applications equipped with the S55 engine. Compatible applications include the BMW M2 CS, M2 Competition, M3, M3 CS, M3 Competition, M4, M4 CS, M4 Competition, and M4 GTS across the specified 2015–2021 model years with automatic or manual transmissions.
