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Ford 122ci specs: 122 ci (2.0L) 4-cylinder, 3.578 x 3.03 in (90.9 x 77 mm) bore and stroke, 9.76:1 compression. Rated 80-85 hp, 1973–1974. OHV.
The Ford 122ci is oversquare — the 3.578" bore exceeds the 3.03" stroke by 18.1% — a layout that favors airflow and RPM over leverage at the crank. The 3.03" stroke does not reach 4,000 ft/min of mean piston speed until about 7,900 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. A rod ratio of 1.65 is in the range most production engines fall in. Each of the 4 cylinders displaces 30.5 ci (500 cc).
9.76:1 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 2 engines in the Ford 122ci family, all of them 122 ci — the differences between them are in compression, heads and rating, not displacement. 2 factory variants share these dimensions, rated from 80 to 85 hp across 1973–1974.
| Displacement | 122 ci / 2 L |
|---|---|
| Bore | 3.578" |
| Stroke | 3.03" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 9.76:1 |
| Rod length | 5" |
| Rod ratio | 1.65 |
| Bore/stroke ratio | 1.181 |
| Piston deck clearance | 0.007" |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Advertised HP | 80–85 hp |
| Years | 1973–1974 |
| Bore/stroke character | 1.181 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,030 ft/min — conservative for a street engine |
| Rod ratio | 1.65 — moderate — the range most production V8s fall in |
| Displacement per cylinder | 30.5 ci |
| Static compression | 9.76:1 — in the range that usually runs on pump premium |
| Intake valve diameter | 1.661" |
|---|---|
| Exhaust valve diameter | 1.425" |
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 |
|---|---|---|
| 1973 | 85 hp | — |
| 1974 | 80 hp | — |