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Cadillac L61 specs: 368 ci (6.0L) 8-cylinder, 3.799 x 4.059 in (96.5 x 103.1 mm) bore and stroke, 8.2:1 compression. Rated 145 hp, 1980.
The Cadillac 368 Series (L61) is undersquare — the 4.0591" stroke exceeds the 3.7992" bore by 6.4% — a layout that trades peak RPM for leverage and torque low in the range. The 4.0591" stroke puts mean piston speed at 4,000 ft/min around 5,900 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 46.0 ci (754 cc).
8.2:1 on iron heads is low by modern standards and generally happy on regular pump fuel.
It is one of 3 engines in the 368 Series family, all of them 368 ci — the differences between them are in compression, heads and rating, not displacement. 2 factory variants share these dimensions, rated at 145 hp in 1980.
| Displacement | 368 ci / 6 L |
|---|---|
| Bore | 3.7992" |
| Stroke | 4.0591" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 8.2:1 |
| Bore/stroke ratio | 0.936 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Firing order | 1-5-6-3-4-2-7-8 |
| Advertised HP | 145 hp |
| Years | 1980 |
| Bore/stroke character | 0.936 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 4,059 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 46.0 ci |
| Static compression | 8.2:1 — 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 |
|---|---|---|
| 1980 | — | L61 |
| 1980 | 145 hp | L61 |
3 factory vehicles, 1980. Each year opens that model's engine table.