See other engines in this family
Mercury 385 specs: 460 ci (7.5L) 8-cylinder, 4.36 x 3.85 in (110.7 x 97.8 mm) bore and stroke, 8:1 compression. Rated 220 hp. OHV. Rod ratio and piston speed.
The Mercury 385 is oversquare — the 4.36" bore exceeds the 3.85" stroke by 13.2% — a layout that favors airflow and RPM over leverage at the crank. The 3.85" stroke puts mean piston speed at 4,000 ft/min around 6,250 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 57.5 ci (942 cc).
8:1 on iron heads is low by modern standards and generally happy on regular pump fuel.
It is one of 10 engines in the 385 family, the largest at 460 ci. 2 factory variants share these dimensions, rated at 220 hp. Factory fitments include the Mercury Grand Marquis, Mercury Colony Park.
| Displacement | 460 ci / 7.5 L |
|---|---|
| Bore | 4.36" |
| Stroke | 3.85" |
| Cylinders | 8 |
| Compression ratio | 8:1 |
| Bore/stroke ratio | 1.132 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Advertised HP | 220 hp |
| Bore/stroke character | 1.132 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,850 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 57.5 ci |
| Static compression | 8:1 — low by modern standards, generally happy on regular pump fuel |
Each link opens the calculator with this engine's specs already filled in.
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
|---|---|---|
| — | 220 hp | 460 Low Comp |
| — | 220 hp | 460 |