Which Plymouth Valiant version to buy — engines, horsepower, and generation-by-generation specs
The Plymouth Valiant to choose is not “the Valiant” in general: the catalogue lists 3 generations (1960–1973) and 10 named versions, and the spread is large. In 3 generation (1967–1973, Sedan 2-doors) output runs from 117 hp on 2.8 MT / 2.8 AT to 233 hp on 5.2 MT / 5.2 AT — 116 hp more, almost double. Torque on those same poles is 210 Nm versus 461 Nm (+251 Nm, 2.2 times).
The Plymouth Valiant to choose is not “the Valiant” in general: the catalogue lists 3 generations (1960–1973) and 10 named versions, and the spread is large. In 3 generation (1967–1973, Sedan 2-doors) output runs from 117 hp on 2.8 MT / 2.8 AT to 233 hp on 5.2 MT / 5.2 AT — 116 hp more, almost double. Torque on those same poles is 210 Nm versus 461 Nm (+251 Nm, 2.2 times). 1 generation (1960–1962, Coupe) has a single measured car: 3.7 AT at 145 hp and 1250 kg kerb weight. 2 generation (1963–1966, Cabrio) has 0 versions in this dataset, so 1963–1966 body-year searches cannot be answered with engine, weight, or mpg numbers here. All figures below are only those in the data; acceleration, top speed, mpg, dimensions, wheelbase, wheels, and ground clearance are not measured unless a number is written.
Plymouth Valiant generations: what actually changed
1 generation (1960–1962), Coupe, 1 version. The only catalogue line is 3.7 AT: Gasoline, 3687 cc, 6 cylinders, V-shaped, Carburetor, Automatic 3, RWD, 145 hp (106 kW). Peak rpm, torque, valves per cylinder, boost, compression, bore × stroke, tank, 0–100, top speed, and mpg are not measured. Kerb weight is 1250 kg; gross weight is not measured. Front suspension Independent, torsion; rear Dependent, leaf spring; Drum / Drum brakes. Engine placement is Front, longitudinal — the only generation where that field is filled.
2 generation (1963–1966), Cabrio, 0 versions. Years people search (1963, 1964, 1965, 1966) sit in this window, but this file has no horsepower, no displacement, no weight, no tank. Those years cannot be ranked against 1960–1962 or 1967–1973 on arithmetic. Restyling is not a fourth generation in this data.
3 generation (1967–1973), Sedan 2-doors, 9 versions. Every line is Gasoline, Carburetor, No boost, RWD, tank 68 l, Independent torsion front / Dependent leaf spring rear, Drum / Drum. Body is no longer Coupe or Cabrio. Engines are Inline 6 or V-shaped 8, not the V-shaped 6 of 1 generation. Two gearbox families: Manual 3 (and one Manual 4) versus Automatic 3. Two 4.5 MT rows share the same name and the same 193 hp / 4492 cc figures; they are not two power levels.
Plymouth Valiant engine options and horsepower (all named versions)
| Version | Generation | hp (kW @ rpm) | Nm @ rpm | cc | Fuel | Cyl. / layout | Boost | Gearbox | Drive |
|---|---|---|---|---|---|---|---|---|---|
| 3.7 AT | 1, 1960–1962 | 145 (106, rpm not measured) | not measured | 3687 | Gasoline | 6 / V-shaped | not measured | Automatic 3 | RWD |
| 2.8 MT | 3, 1967–1973 | 117 (86 @ 4400) | 210 @ 2400 | 2799 | Gasoline | 6 / Inline | No | Manual 3 | RWD |
| 2.8 AT | 3 | 117 (86 @ 4400) | 210 @ 2400 | 2799 | Gasoline | 6 / Inline | No | Automatic 3 | RWD |
| 3.7 MT | 3 | 147 (108 @ 4000) | 292 @ 2400 | 3694 | Gasoline | 6 / Inline | No | Manual 3 | RWD |
| 3.7 AT | 3 | 147 (108 @ 4000) | 292 @ 2400 | 3694 | Gasoline | 6 / Inline | No | Automatic 3 | RWD |
| 4.5 MT | 3 | 193 (142 @ 4400) | 353 @ 2000 | 4492 | Gasoline | 8 / V-shaped | No | Manual 3 | RWD |
| 4.5 AT | 3 | 193 (142 @ 4400) | 353 @ 2000 | 4492 | Gasoline | 8 / V-shaped | No | Automatic 3 | RWD |
| 4.5 MT (second row, same 193 hp) | 3 | 193 (142 @ 4400) | 353 @ 2000 | 4492 | Gasoline | 8 / V-shaped | No | Manual 3 | RWD |
| 5.2 MT | 3 | 233 (172 @ 4400) | 461 @ 2400 | 5210 | Gasoline | 8 / V-shaped | No | Manual 4 | RWD |
| 5.2 AT | 3 | 233 (172 @ 4400) | 461 @ 2400 | 5210 | Gasoline | 8 / V-shaped | No | Automatic 3 | RWD |
Specific output from the same table: 2.8 versions 117 / 2.799 ≈ 41.8 hp/l; 3 generation 3.7 147 / 3.694 ≈ 39.8 hp/l; 4.5 193 / 4.492 ≈ 43.0 hp/l; 5.2 233 / 5.210 ≈ 44.7 hp/l; 1 generation 3.7 AT 145 / 3.687 ≈ 39.3 hp/l. The 5.2 pair is the densest; the two 3.7 generations are the least dense and sit within 0.5 hp/l of each other.
Plymouth Valiant specs: 3.7 AT of 1 generation versus 3.7 AT of 3 generation
Both are named 3.7 AT, Automatic 3, RWD, Gasoline, 6 cylinders, Carburetor. They are not the same engine on paper. Displacement is 3687 cc versus 3694 cc (+7 cc). Power is 145 hp versus 147 hp (+2 hp, +2 kW: 106 versus 108). Layout is V-shaped in 1960–1962 and Inline in 1967–1973. Compression on the later car is 8.4; on the earlier car it is not measured. Bore × stroke on the later 3.7 is 86.5 × 104.8; on 1 generation it is not measured. Torque on 1 generation 3.7 AT is not measured; on 3 generation 3.7 AT it is 292 Nm at 2400. Kerb weight exists only for the Coupe: 1250 kg, or 1250 / 145 ≈ 8.6 kg/hp. 3 generation kerb weight is not measured, so kg/hp cannot be compared across generations. Tank is not measured on 1 generation and 68 l on 3 generation. If the search is a 1960–1962 Coupe, the only version is 3.7 AT. If the search is a 1967–1973 two-door sedan with a similar badge, 3.7 AT is the automatic six; 3.7 MT is the same 147 hp / 292 Nm with Manual 3.
Which Plymouth Valiant engine in 3 generation: 2.8, 3.7, 4.5, or 5.2
2.8 MT and 2.8 AT are the smallest: 2799 cc, Inline 6, 117 hp, 210 Nm, compression 9, bore × stroke 86.5 × 79.4, peak power 4400 rpm. They are 116 hp and 251 Nm below 5.2. Versus 3.7 they give up 30 hp (26%) and 82 Nm (39%) while using 895 cc less (3694 − 2799). Choose 2.8 MT if the gearbox must be Manual 3; 2.8 AT if Automatic 3. Power, torque, and tank (68 l) do not change with the box.
3.7 MT and 3.7 AT are the middle sixes: 147 hp at 4000 rpm (the lowest listed power peak in 3 generation), 292 Nm at 2400, compression 8.4 (lowest measured CR in this generation), stroke 104.8 versus 79.4 on 2.8 with the same 86.5 bore. They sit 46 hp and 61 Nm below 4.5, and 86 hp / 169 Nm below 5.2. Versus 2.8, the extra 0.9 litres buy 30 hp and 82 Nm. 3.7 AT matches the automatic habit of 1 generation 3.7 AT without matching its V-shaped layout or its 1250 kg figure.
4.5 MT, 4.5 AT, and the second 4.5 MT are the first V-shaped 8: 4492 cc, 193 hp at 4400, 353 Nm at 2000 (the lowest torque peak rpm in the file — 2000 versus 2400 on 2.8, 3.7, and 5.2). Compression 9, bore × stroke 92.2 × 84.1. Versus 3.7: +46 hp, +61 Nm, +798 cc. Versus 5.2: −40 hp (17% less than 233), −108 Nm (23% less than 461), −718 cc. Manual and automatic 4.5 do not differ in hp or Nm; both manuals in the list are Manual 3, not Manual 4. There is no second power rating to split the two 4.5 MT names.
5.2 MT and 5.2 AT are the top of the catalogue: 5210 cc, 233 hp at 4400, 461 Nm at 2400, compression 9.2 (highest measured), bore × stroke 99.3 × 84.1. 5.2 MT is the only Manual 4; 5.2 AT is Automatic 3. That four-speed is the only transmission difference that is not a 3-speed swap on an otherwise identical engine. 5.2 versus 2.8 is +2411 cc, +116 hp, +251 Nm. 5.2 versus 4.5 is the smallest V8 step in litres but the largest torque step among the eights.
Manual versus automatic, same engine: 2.8, 3.7, 4.5, and 5.2 pairs share hp, Nm, cc, cylinders, layout, boost (No), fuel (Gasoline), drive (RWD), and 68 l tank. The choice is gearbox count and type, not a hidden power bump. The exception is 5.2 MT (4 speeds) versus 5.2 AT (3 speeds).
Plymouth Valiant performance, mpg, weight, and dimensions — what is not measured
0–100, top speed, city / highway / combined consumption, CO2, and eco class are not measured on every version, including 1971-style 3 generation lines people search for horsepower and mpg. Plymouth Valiant mpg cannot be ranked from this file. Dimensions, wheelbase, wheel size, and ground clearance are not measured on every version; length and 1964–1968 dimension queries have no numbers here.
Weight: only 1 generation 3.7 AT has kerb weight 1250 kg. Gross weight is not measured everywhere. 3 generation kerb is not measured, so 5.2 at 233 hp cannot be shown as lighter or heavier per horsepower than 2.8 at 117 hp. Tank 68 l is the only capacity on 3 generation; 1 generation tank is not measured. Brakes are Drum / Drum on all rows that list brakes.
Which Plymouth Valiant version to choose
- Need the only 1960–1962 Coupe in the data: 3.7 AT — 145 hp, 3687 cc, V-shaped 6, Automatic 3, 1250 kg. No other 1 generation engine is listed.
- Need a 1963–1966 Cabrio: 2 generation has 0 versions; specs, horsepower, and weight for those years are not measured.
- Need the least power and smallest six in 1967–1973: 2.8 MT or 2.8 AT — 117 hp, 210 Nm, 2799 cc, 41.8 hp/l.
- Need a 3.7-class six in the sedan years: 3.7 MT or 3.7 AT — 147 hp, 292 Nm, Inline 6, 8.4 compression. Versus 1 generation 3.7 AT this is +2 hp and a different cylinder layout, not a larger round number.
- Need a V-shaped 8 without the 5.2 step: 4.5 MT or 4.5 AT — 193 hp, 353 Nm at 2000 rpm. The two 4.5 MT rows do not split by horsepower.
- Need the maximum hp, Nm, compression, and the only 4-speed: 5.2 MT — 233 hp, 461 Nm, 9.2, Manual 4. 5.2 AT matches the engine and drops to Automatic 3.
- Need automatic specifically: 2.8 AT, 3.7 AT, 4.5 AT, 5.2 AT in 3 generation, or 3.7 AT in 1 generation. None of those automatics add hp over the matching manual.
- Cannot choose on mpg, 0–100, price, length, wheelbase, or 3 generation weight: those fields are not measured (price is not in the data at all).
For 1967–1973, the arithmetic order by power is 2.8 (117) → 3.7 (147) → 4.5 (193) → 5.2 (233). Each step is +30, +46, +40 hp. Torque order is the same: 210 → 292 → 353 → 461. If the question is which version to buy inside this catalogue, pick the generation first (Coupe 3.7 AT, empty Cabrio years, or Sedan 2-doors nines), then pick displacement by those steps, then pick Manual 3, Manual 4 (5.2 MT only), or Automatic 3.