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Honda H23A1 specs: 2.3L (137.9 ci) 4-cylinder, 87 x 95 mm (3.4252 x 3.7402 in) bore and stroke, 9.8:1 compression. Rated 160 hp, 1992–1996.
The Honda H23A1 is undersquare — the 3.7402" stroke exceeds the 3.4252" bore by 8.4% — a layout that trades peak RPM for leverage and torque low in the range. The 3.7402" stroke puts mean piston speed at 4,000 ft/min around 6,400 RPM, which is where a production bottom end is generally considered at its limit. Each of the 4 cylinders displaces 34.5 ci (565 cc).
9.8:1 on aluminum heads is in the range that usually runs on pump premium; aluminum sheds heat faster than iron, which makes the same number a little more forgiving.
It is one of 7 engines in the H-series family, the largest at 137.9 ci. 5 factory variants share these dimensions, rated at 160 hp across 1992–1996.
| Displacement | 137.9 ci / 2.3 L |
|---|---|
| Bore | 3.4252" |
| Stroke | 3.7402" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 9.8:1 * |
| Bore/stroke ratio | 0.916 |
* Compression ratio from a single source; not yet cross-verified.
| Block material | aluminum |
|---|---|
| Head material | aluminum |
| Valvetrain | DOHC |
| Fuel type | gas |
| Advertised HP | 160 hp |
| Years | 1992–1996 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 1992 | H23A1 net | 160 @ 5800 | 156 lb-ft @ 4500 | — |
| 1993 | H23A1 net | 160 @ 5800 | 156 lb-ft @ 4500 | — |
| 1994 | H23A1 net | 160 @ 5800 | 156 lb-ft @ 4500 | — |
| 1995 | H23A1 net | 160 @ 5800 | 156 lb-ft @ 4500 | — |
| 1996 | H23A1 net | 160 @ 5800 | 156 lb-ft @ 4500 | — |
Factory specification sheet.
| Bore/stroke character | 0.916 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 3,740 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 34.5 ci |
| Static compression | 9.8:1 — in the range that usually runs on pump premium |
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 |
|---|---|---|
| 1992 | 160 hp | H23A1 |
| 1993 | 160 hp | H23A1 |
| 1994 | 160 hp | H23A1 |
| 1995 | 160 hp | H23A1 |
| 1996 | 160 hp | H23A1 |
1 factory vehicle, 1992–1996. Each year opens that model's engine table.