Buyer’s Guide — Austin Healey 100-6
What to know before buying an Austin Healey 100-6.
Overview
The Austin Healey 100-6 (BN4 and BN6) was produced from 1956 to 1959, bridging the gap between the four-cylinder 100 and the six-cylinder 3000. Approximately 14,400 were built. It introduced the BMC C-series 2,639 cc six-cylinder engine, initially producing 102 bhp. Early BN4 models had a 2+2 seating configuration, while the later BN6 was a two-seater. The six-port head introduced in late 1957 improved power to around 117 bhp.
What to Look For — Body & Chassis
| Chassis | Same box-section design as the 100 — check front crossmember, spring hangers, and outriggers for corrosion. Lift the car and inspect thoroughly underneath. |
| Front Shroud | Now features a bonnet and separate wings rather than the 100’s one-piece shroud. Check wing-to-shroud joints for corrosion and panel fit. |
| Floor Pans | Steel floors rust from below. Check under carpets and from underneath. |
| Rear Wings | Prone to rust at the bottoms and around the wheel arches. Check for filler. |
| Door Skins | Check bottom edges for rust. Replacement skins are available. |
What to Look For — Mechanical
| Engine | The C-series six is smooth but can be oil-hungry if worn. Check oil pressure and listen for timing chain rattle on startup. Early two-port heads produce less power — six-port heads are more desirable. |
| Gearbox | Four-speed with optional overdrive. Synchros wear on 2nd gear. Check for smooth engagement and no jumping out of gear. |
| Overdrive | Laycock unit — must engage cleanly. Test at driving speed. Non-functional overdrive is common and expensive to repair. |
| Cooling | The six-cylinder can run hot — check for a well-functioning thermostat and clean radiator. Overheating history can mean a cracked head. |
| Brakes | Drums all round on early cars, front discs available as upgrade. Standard drums are adequate but require proper adjustment. |
Parts Availability
Very good. The 100-6 shares many parts with the more numerous 3000. Suppliers include Moss Motors, Denis Welch, British Parts Northwest, and Healey specialists worldwide. Most mechanical and body parts are readily available.
What a Good One Should Feel Like
Smoother and more refined than the four-cylinder 100 but slightly heavier. The six-cylinder engine should pull cleanly from low revs with no roughness. Steering is heavier than the 100 but still communicative. Six-port head cars feel noticeably livelier. The car should cruise comfortably with overdrive engaged.
Price Guide (Approximate, 2026)
| Project / Needs Restoration | $35,000 – $55,000 |
| Good Driver | $60,000 – $85,000 |
| Excellent / Restored | $90,000 – $130,000 |
| BN6 Two-Seater | Typically 10–15% more than equivalent BN4 |
Six-port head cars are more desirable. BN6 two-seaters are less common and command a premium.