BMW S38B38 Stroker Kit by 5150 AutoSport, 4.2L

Bigger displacement, more torque and more power. Our 5150 Autosport 4.2L Stroker kit is specifically designed for BMW S38B38 Euro engines.

Utilizing CP-Carrillo Forged Pistons and Carrillo or SP Components Forged Connecting Rods, as well as our 97mm Stroke 5150 AutoSport 4340 Billet Steel Crankshaft, this kit has stood up to the tests and trials of high horsepower application time and time again. We only sell you the products that we have used and tested ourselves.

Other teams have applied this kit in Hill Climb, Road Racing, Endurance Racing, Rally, Time Attack, Drag Racing, Roll Racing, Drifting, and Street applications, all with powerful results.

Benefits of Stroking an Engine

- With higher displacement, your engine will produce greater power and torque, thanks to increased cylinder volume and improved air-fuel mixture combustion
- The longer stroke in the crankshaft increases the leverage on the connecting rods, resulting in increased torque output at lower RPMs
- Improved throttle response
- Increased horsepower

Kit Contents 

- 5150 AutoSport 4340 Billet Steel Crankshaft, 97mm Stroke 
- SP Components Lightweight Connecting Rods
    - Optional upgrade to Carrillo Connecting Rods
- CP-Carrillo  Forged Pistons
    - CP-Carrillo Piston Wrist Pins 
    - CP-Carrillo Piston Rings 
    - CP-Carrillo Piston Wire Locks

Our stroker kit offers the following displacements depending on the selected bore size:

93.5 mm bore size results in a displacement 3996 cc
94 mm bore size results in a displacement 4039 cc
94.5 mm bore size results in a displacement of 4082 cc
95 mm bore size yields a displacement of 4125 cc
95.5 mm bore size provides a displacement of 4169 cc
96 mm bore size provides a displacement of 4212 cc

Don't see the piston combination you're looking for? Have more questions? Contact our engine build advisors to discuss your next build.