1985 BMW 6 Series 635CSi

1985 BMW M635CSi Euro 3.9L Dinan Stroker 5-Speed – San Francisco, CA

A rare opportunity to own a true BMW M Series icon, this 1985 BMW M635CSi represents the pinnacle of BMW’s Motorsport engineering from the golden era of analog performance. As a European-spec example enhanced with a Dinan 3.9L stroker engine, 5-speed manual transmission, and over $30,000 in concours-level and performance upgrades, this is a “no-excuses” E24 M635CSi—fully sorted, California smog legal, and ready to be driven.

Finished in factory Polaris Metallic over black leather, this example stands apart from typical European imports that often suffer from deferred maintenance or incomplete federalization. Instead, this M635CSi has been comprehensively upgraded and refined into a turnkey driver that delivers both vintage character and modern reliability.

Vehicle Features
- Dinan 3.9L Stroker Inline-6 Engine (M88/3 Platform)
- Dinan Stage 2 ECU Performance Chip
- 5-Speed Manual Transmission
- Rear-Wheel Drive (RWD)
- European-Spec M635CSi (E24 Chassis)
- Factory Polaris Metallic Exterior
- Black Leather Interior
- Apple CarPlay Infotainment System (Pioneer Pop-Up Screen)
- Triple-View Camera System (Front, Interior, Rear)
- Genuine BMW M-Technic Side Skirts & Rear Apron
- Period-Correct 16" BBS Basketweave Wheels
- New Michelin Tires (225/50/16 Square Setup)
- California Smog Legal Configuration
- Clean Title
- 102k Miles (Odometer Reading)
- Excellent, Fully Sorted Condition

Recent Upgrades & Improvements (Over $30,000 Invested)
- Complete powder-coated and adjustable rear subframe and trailing arms modified and equipped by Garagistic with red polyurethane bushings ($3,200)
- German Alcantara headliner replacement along with rear shelf, front door panels, and rear side panels ($3,150)
- Triple-view camera system, upgraded speakers, and Pioneer pop-up touchscreen with - - Apple CarPlay ($2,800)
- Performance thicker front and rear sway bars with new stabilizer links ($1,200)
- New BMW battery ($395)
- New Michelin tires ($975)
- Genuine BMW M-Tech side skirts and rear apron sourced from Europe with OEM fasteners and lift points ($7,500)
- Hood and front nose refinished; side skirts and rear apron painted and installed ($5,500)
California-legal catalytic converter installed with Billy Boat stainless exhaust system ($2,200)
- Full brake system overhaul including ABS sensors, rotors, pads, and fluid flush ($2,450)
- Alternator voltage regulator replaced with new belt and coolant distribution hose ($900)

Vehicle History & Condition
This M635CSi has been transformed into a fully sorted, no-excuses example through extensive recent investment. The Dinan-built 3.9L stroker engine delivers strong, reliable performance, while the transmission, suspension, and braking systems operate exactly as intended.

The vehicle presents cleanly inside and out, with a solid undercarriage and no known mechanical concerns. With its combination of documented upgrades, California compliance, and enthusiast-focused enhancements, this example stands out as a highly usable and refined classic.

Why This M635CSi Matters

The BMW M635CSi is one of the most important early M cars ever produced—hand-built, motorsport-derived, and designed for drivers who value connection and performance. This example goes a step further, combining that heritage with a professionally built Dinan stroker engine and modern upgrades that eliminate the typical compromises of classic ownership.

For collectors and enthusiasts alike, this represents a rare chance to own a true BMW M Series car that needs nothing—just to be driven and enjoyed. Call Caruso Classics for more details. 877-743-0322