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Dodge 225ci (1960–1987) specs: 225 ci (3.7L) 6-cylinder, 3.402 x 4.13 in (86.4 x 104.9 mm) bore and stroke. Rated 95-145 hp, 1960–1987.
The Dodge 225ci (1960–1987) is undersquare — the 4.1299" stroke exceeds the 3.4016" bore by 17.6% — a layout that trades peak RPM for leverage and torque low in the range. The 4.1299" stroke puts mean piston speed at 4,000 ft/min around 5,800 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.622 is in the range most production engines fall in. Each of the 6 cylinders displaces 37.5 ci (615 cc).
It is one of 8 engines in the Dodge 225ci family, all of them 225 ci — the differences between them are in compression, heads and rating, not displacement. 49 factory variants share these dimensions, rated from 95 to 145 hp across 1960–1987.
| Displacement | 225 ci / 3.7 L |
|---|---|
| Bore | 3.4016" |
| Stroke | 4.1299" |
| Cylinders | 6 |
| Compression ratio | 8.2–8.5:1 (published figures vary) |
| Rod length | 6.699" |
| Rod ratio | 1.622 |
| Bore/stroke ratio | 0.824 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Firing order | 1-5-3-6-2-4 |
| Advertised HP | 95–145 hp |
| Years | 1960–1987 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. | Duration int / exh | Valve lift int / exh | LSA |
|---|---|---|---|---|---|---|---|
| 1960 | gross | 145 @ 4000 | 215 lb-ft @ 2800 | 8.5:1 | — | — | — |
| 1961 | gross | 145 @ 4000 | 215 lb-ft @ 2800 | 8.2:1 | — | — | — |
| 1962 | gross | 145 @ 4000 | 215 lb-ft @ 2800 | 8.2:1 | — | — | — |
| 1963 | gross | 145 @ 4000 | 215 lb-ft @ 2800 | 8.2:1 | — | — | — |
| 1964 | gross | 145 @ 4000 | 215 lb-ft @ 2800 | 8.4:1 | — | — | — |
| 1965 | gross | 145 @ 4000 | 215 lb-ft @ 2400 | 8.4:1 | — | — | — |
| 1967 | gross | 145 @ 4000 | 215 lb-ft @ 2400 | 8.4:1 | 240° / 236° | 0.395" | 111° |
| 1968 | gross | 145 @ 4000 | 215 lb-ft @ 2400 | 8.4:1 | 240° / 236° | 0.395" | 111° |
| 1969 | gross | 145 @ 4000 | 215 lb-ft @ 2400 | 8.4:1 | 240° / 236° | 0.394" / 0.390" | 111° |
| 1971 | gross | 145 @ 4000 | 215 lb-ft @ 2400 | 8.4:1 | — | — | — |
| 1972 | net | 110 @ 4000 | 185 lb-ft @ 2000 | 8.4:1 | — | — | — |
Factory specification sheet. Durations are the factory's advertised figures at the basis printed on the sheet, not duration at .050" lift; lobe separation is calculated from the printed valve timing.
| Bore/stroke character | 0.824 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 4,130 ft/min — in the range typical of performance street engines |
| Rod ratio | 1.622 — moderate — the range most production V8s fall in |
| Displacement per cylinder | 37.5 ci |
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 |
|---|---|---|
| 1960 | 145 hp | — |
| 1961 | 145 hp | — |
| 1962 | 140 hp | — |
| 1962 | 145 hp | — |
| 1963 | 140 hp | — |
| 1963 | 145 hp | — |
| 1964 | — | — |
| 1964 | 140 hp | — |
| 1964 | 145 hp | — |
| 1965 | — | — |
| 1965 | 140 hp | — |
| 1965 | 145 hp | — |
| 1966 | 140 hp | — |
| 1966 | 145 hp | — |
| 1967 | 140 hp | — |
| 1967 | 145 hp | — |
| 1968 | — | — |
| 1968 | 145 hp | — |
| 1969 | — | — |
| 1969 | 145 hp | — |
| 1970 | — | — |
| 1970 | 140 hp | — |
| 1970 | 145 hp | — |
| 1971 | — | — |
| 1971 | 140 hp | — |
| 1971 | 145 hp | — |
| 1972 | — | — |
| 1972 | 110 hp | — |
| 1973 | 105 hp | — |
| 1973 | 110 hp | — |
| 1974 | — | — |
| 1974 | 105 hp | — |
| 1975 | — | — |
| 1975 | 95 hp | — |
| 1976 | — | — |
| 1976 | 100 hp | — |
| 1977 | — | — |
| 1977 | 105 hp | — |
| 1978 | — | — |
| 1978 | 105 hp | — |
| 1979 | — | — |
| 1979 | 110 hp | — |
| 1980 | — | — |
| 1981 | — | — |
| 1982 | — | — |
| 1984 | — | — |
| 1985 | — | — |
| 1986 | — | — |
| 1987 | — | — |
11 factory vehicles, 1960–1987. Each year opens that model's engine table.