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Ford 281ci specs: 281 ci (4.6L) 8-cylinder, 3.551 x 3.543 in (90.2 x 90 mm) bore and stroke, 10.1:1 compression. Rated 430 hp, 2006–2007. OHV.
The Ford 281ci is close to square: 3.551" bore against 3.543" stroke, within 0.2%, which splits the difference between a high-revving layout and a torque layout. The 3.543" stroke puts mean piston speed at 4,000 ft/min around 6,750 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.675 is in the range most production engines fall in. Each of the 8 cylinders displaces 35.1 ci (576 cc).
10.1:1 on iron heads is in the range that usually runs on pump premium; iron holds heat, so treat it as the less forgiving side of that range.
It is one of 21 engines in the Ford 281ci family, all of them 281 ci — the differences between them are in compression, heads and rating, not displacement. 2 factory variants share these dimensions, rated at 430 hp across 2006–2007.
| Displacement | 281 ci / 4.6 L |
|---|---|
| Bore | 3.551" |
| Stroke | 3.543" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 10.1:1 |
| Rod length | 5.933" |
| Rod ratio | 1.675 |
| Bore/stroke ratio | 1.002 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Advertised HP | 430 hp |
| Years | 2006–2007 |
| Bore/stroke character | 1.002 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 3,543 ft/min — in the range typical of performance street engines |
| Rod ratio | 1.675 — moderate — the range most production V8s fall in |
| Displacement per cylinder | 35.1 ci |
| Static compression | 10.1:1 — in the range that usually runs on pump premium |
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 |
|---|---|---|
| 2006 | 430 hp | — |
| 2007 | 430 hp | — |