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Volvo B21FT specs: 2.1L (130 ci) 4-cylinder, 92 x 80 mm (3.6220 x 3.1496 in) bore and stroke, 7.5:1 compression. Rated 127 hp, 1981–1985.
The Volvo B21FT is oversquare — the 3.622" bore exceeds the 3.1496" stroke by 15.0% — a layout that favors airflow and RPM over leverage at the crank. The 3.1496" stroke does not reach 4,000 ft/min of mean piston speed until about 7,600 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 4 cylinders displaces 32.5 ci (533 cc).
7.5:1 is low by modern standards and generally happy on regular pump fuel.
It is one of 2 engines in the Volvo 130ci family, all of them 130 ci — the differences between them are in compression, heads and rating, not displacement. 5 factory variants share these dimensions, rated at 127 hp across 1981–1985.
| Displacement | 130 ci / 2.1 L |
|---|---|
| Bore | 3.622" |
| Stroke | 3.1496" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 7.5:1 |
| Bore/stroke ratio | 1.15 |
| Fuel type | gas |
|---|---|
| Advertised HP | 127 hp |
| Years | 1981–1985 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 1981 | B21FT net | 127 @ 5400 * | 150 lb-ft @ 3750 * | 7.5:1 * |
| 1983 | B21FT net | 127 @ 5400 | 150 lb-ft @ 3750 | 7.5:1 |
Factory specification sheet. * Not yet cross-verified.
| Bore/stroke character | 1.150 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,150 ft/min — conservative for a street engine |
| Displacement per cylinder | 32.5 ci |
| Static compression | 7.5:1 — 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 |
|---|---|---|
| 1981 | 126–127 hp | B21FT |
| 1982 | 127 hp | B21FT |
| 1983 | 127 hp | B21FT |
| 1984 | — | B21FT |
| 1985 | — | B21FT |
1 factory vehicle, 1981–1985. Each year opens that model's engine table.