S55 Stage 1 Engine - | F80, F82, F83, F87 | M2 CS, M2 Competition, M3, M3 CS, M3 Competition, M4, M4 CS, M4 Competition, M4 GTS
The CarBahn Stage 1 S55 engine is designed for high-performance applications, particularly for BMW F80 M3, F82/F83 M4, and F87 M2C models, and is rated for handling substantial power outputs, including larger turbo setups. This engine is an excellent upgrade for those seeking a significant boost in performance while maintaining the reliability required for daily driving and track use.
Engine components include forged Carrillo connecting rods, forged CP pistons, and a CarBahn pinned crankshaft, which ensures the cam sprocket is securely fixed to the crankshaft to prevent timing issues. The engine also features a full circle main bearing for enhanced durability, high-performance valve springs, and the labor and machine work needed to install these upgraded parts into the block.
The S55 engine is typically not designed to handle large increases in boost beyond OEM specifications. This limitation stems from the design of the crankshaft, where the timing chain sprocket can spin on the end of the crank, causing the camshafts to fall out of time. In extreme cases, this could lead to catastrophic damage, such as valve-to-piston contact. Additionally, the S55 engine uses only half of a standard crankshaft thrust bearing, which can lead to reliability concerns under higher performance conditions. To address these issues, CarBahn pins the timing chain sprocket to the crankshaft and machines the block to accommodate a full-circle thrust main bearing, ensuring optimal performance and durability.
The CarBahn S55 engine is specifically optimized for high boost settings, featuring a reduced compression ratio by 0.5 points compared to the OEM engine. This modification helps to improve performance by allowing for more fuel-air mixture in the combustion chamber and preventing the ignition timing from retarding too much under increased boost pressure. This lowered compression also offers the added benefit of reducing catalyst inlet temperatures, improving driveability on pump gas, and ensuring emissions-legal operation on the street.
Designed to be both stronger and more cost-effective than the BMW OEM factory engine, the CarBahn S55 Stage 1 Engine benefits from Steve Dinan's 46 years of race engine-building expertise. His engines have powered multiple championship-winning cars, including three prototype racing titles and two overall victories at the 24 Hours of Daytona (2011-2013).
Choose CarBahn for superior S55 engine tuning.
Engine Core Acceptance Parameters
Must be complete core (factory engine, from oil pan to valve cover)
Block Requirements
- No holes or cracks in casting
- No holes or crack in covers
- No bore damage that cannot be honed out
- No thrust surface damage
- No journal surfaces damage
- No bolt hole damage that can’t be repaired
Head Requirements
- No holes or cracks in casting
- No holes or crack in covers
- No thrust surface damage
- No journal surfaces damage
- No bolt hole damage that can’t be repaired
Possible Additional Repair Charges
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
Engine Warranty & Additional Information
Our engines are very strong and can often be very reliable even at power levels above what is recommended. The durability usually depends on the quality and the reliability of the tune and other aftermarket components added to the engine management system.
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Engines with CarBahn Software Tunes
All engines listed with a stage number (ex. Stage 1 & Stage 2) are designed to be road car engines and are covered for 2 years, 24,000 miles providing they have a CarBahn tune and there are no other parts on the car that have caused a premature failure. -
Engines with Another Company's Tune
All engines listed with a stage number (ex. Stage 1 & Stage 2) are designed to be road car engines and are covered are covered for 2 year, 24,000 miles providing they you stay under our recommended torque limits. Torque limits are indicated on the product listing. Warranty does not cover failures from the tune or aftermarket fuel injection components that caused the failure. It is CarBahn's full discretion to determine cause of failure. If Torque limit is exceeded, the warranty is for materials and workmanship only. -
Racing Engines
Racing engines are designed to be raced and are covered for materials and workmanship only. Racing engines should be rebuilt periodically based on run time or mileage. Warranty does not cover failures from the tune or aftermarket fuel injection components that caused the failure. It is CarBahn full discretion to determine cause of failure.