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Chrysler B 361 specs: 361 ci (5.9L) 8-cylinder, 4.125 x 3.375 in (104.8 x 85.7 mm) bore and stroke, 9:1 compression. Rated 265 hp, 1961–1964.
The Chrysler B 361 is oversquare — the 4.125" bore exceeds the 3.375" stroke by 22.2% — a layout that favors airflow and RPM over leverage at the crank. The 3.375" stroke does not reach 4,000 ft/min of mean piston speed until about 7,100 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 8 cylinders displaces 45.1 ci (739 cc).
9:1 on iron heads is low by modern standards and generally happy on regular pump fuel.
4 factory variants share these dimensions, rated at 265 hp across 1961–1964.
| Displacement | 361 ci / 5.9 L |
|---|---|
| Bore | 4.125" |
| Stroke | 3.375" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 9:1 |
| Bore/stroke ratio | 1.222 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Firing order | 1-8-4-3-6-5-7-2 |
| Advertised HP | 265 hp |
| Years | 1961–1964 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 1961 | gross | 265 @ 4400 | 380 lb-ft @ 2400 | 9:1 |
| 1962 | gross | 265 @ 4400 | 380 lb-ft @ 2400 | 9:1 |
| 1963 | gross | 265 @ 4400 | 380 lb-ft @ 2400 | 9:1 |
| 1964 | gross | 265 @ 4400 | 380 lb-ft @ 2400 | 9:1 |
Factory specification sheet.
| Bore/stroke character | 1.222 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,375 ft/min — conservative for a street engine |
| Displacement per cylinder | 45.1 ci |
| Static compression | 9:1 — 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 |
|---|---|---|
| 1961 | 265 hp | B 361 |
| 1962 | 265 hp | B 361 |
| 1963 | 265 hp | B 361 |
| 1964 | 265 hp | B 361 |
1 factory vehicle, 1961–1964. Each year opens that model's engine table.