K-Swap Mini Cooper

The stock engine in a 2007 Mini Cooper was unreliable, underpowered, and increasingly expensive to maintain. Rather than buy an off-the-shelf swap kit, the goal was to design and build the entire conversion from scratch.

• Replace the factory engine with a Honda K-Series engine, known for reliability and aftermarket support.
• Build real fabrication skills — welding, custom metal parts, automotive wiring.

• Developed a custom signal-converter PCB with STM32 firmware to translate K-Series engine signals into Mini Cooper equivalents to maintain OEM RPM gauge functionality.
• Designed, prototyped, and welded engine mounts from ¼" mild steel using flux-core welding.
• Rewired the engine harness by repinning an off-the-shelf harness and adding the correct connectors for the swap.
• Fabricated the shifter bracket and exhaust downpipe live on the car to work around complex geometry.
• CAD'd and 3D-printed prototypes, welding jigs, bushings, and a limit-switch bracket.
• Converted the throttle pedal from drive-by-wire to drive-by-cable to match the K-Series intake.
• Serviced the used K-Series engine (sourced from a 2004 Acura TSX) — new clutch and replaced all oil seals

• One-of-a-kind engine swap completed without an existing kit or outside labour — over $6,000 CAD in savings versus a shop-installed kit swap.
• Built hands-on fabrication skills from welding and tapping holes to cutting metal and modifying parts on the fly.
• Adapted to unexpected problems through iterative design and engineering reasoning.
• Spans mechanical, electrical, and software engineering in a single build — mounts, wiring harness, and a custom PCB with firmware.

Final assembly, tuning, and road testing are ongoing — updates will be posted here as the swap is finished.