See other engines in this family
Mercury FE (1961–1967) specs: 390 ci (6.4L) 8-cylinder, 4.05 x 3.784 in (102.9 x 96.1 mm) bore and stroke. Rated 250-330 hp, 1961–1967.
The Mercury FE (1961–1967) is oversquare — the 4.05" bore exceeds the 3.784" stroke by 7.0% — a layout that favors airflow and RPM over leverage at the crank. The 3.784" stroke puts mean piston speed at 4,000 ft/min around 6,350 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.715 is in the range most production engines fall in. Each of the 8 cylinders displaces 48.8 ci (799 cc).
It is one of 24 engines in the FE family, sitting between the 352 ci and 428 ci members. 15 factory variants share these dimensions, rated from 250 to 330 hp across 1961–1967.
| Displacement | 390 ci / 6.4 L |
|---|---|
| Bore | 4.05" |
| Stroke | 3.784" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 8.9–10.8:1 (published figures vary) |
| Rod length | 6.488" |
| Rod ratio | 1.715 |
| Bore/stroke ratio | 1.07 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Firing order | 1-5-4-2-6-3-7-8 |
| Advertised HP | 250–330 hp |
| Years | 1961–1967 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. | Duration int / exh | Valve lift int / exh | LSA |
|---|---|---|---|---|---|---|---|
| 1961 | gross | 300 @ 4600 | 427 lb-ft @ 2800 | — | — | — | — |
| 1962 | gross | 300 @ 4600 * | — | 9.6:1 * | — | — | — |
| 1963 | gross | 250 @ 4400 | — | 8.9:1 | — | — | — |
| 1963 | gross | 300 @ 4600 | 427 lb-ft @ 2800 | 10.8:1 | — | — | — |
| 1964 | gross | 250 @ 4400 | 378 lb-ft @ 2400 | 9.4:1 | — | — | — |
| 1964 | gross | 266 @ 4400 | 378 lb-ft @ 2400 | 9.4:1 | — | — | — |
| 1964 | gross | 300 @ 4600 | 427 lb-ft @ 2800 | 10.1:1 | — | — | — |
| 1964 | gross | 330 @ 5000 | 427 lb-ft @ 3200 | 10.1:1 | — | — | — |
| 1966 | gross | 265 @ 4400 | 401 lb-ft @ 2600 | 9.5:1 | — | — | — |
| 1966 | gross | 275 | — | 9.5:1 | — | — | — |
| 1967 | Y/H gross | 270 @ 4400 | 403 lb-ft @ 2600 | 9.5:1 | — | — | — |
| 1967 | S gross | 320 @ 4800 | 427 lb-ft @ 3200 | 10.5:1 | 270° | 0.481" / 0.490" | 115° |
Factory specification sheet. Durations are the factory's advertised figures at the basis printed on the sheet, not duration at .050" lift; lobe separation is calculated from the printed valve timing. * Not yet cross-verified.
| Bore/stroke character | 1.070 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,784 ft/min — in the range typical of performance street engines |
| Rod ratio | 1.715 — moderate — the range most production V8s fall in |
| Displacement per cylinder | 48.8 ci |
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 |
|---|---|---|
| 1961 | 300 hp | — |
| 1962 | 300 hp | — |
| 1963 | 250 hp | — |
| 1963 | 300 hp | — |
| 1963 | 330 hp | — |
| 1964 | 250 hp | — |
| 1964 | 266 hp | — |
| 1964 | 300 hp | — |
| 1964 | 330 hp | — |
| 1965 | 250 hp | — |
| 1966 | 265 hp | — |
| 1966 | 275 hp | — |
| 1967 | — | — |
| 1967 | 270 hp | — |
| 1967 | 320 hp | — |
5 factory vehicles, 1961–1967. Each year opens that model's engine table.