See other engines in this family
Honda EM specs: 1.5L (90.8 ci) 4-cylinder, 74 x 86.5 mm (2.9134 x 3.4055 in) bore and stroke, 8.8:1 compression. Rated 67 hp, 1980–1983.
The Honda E-series (EM) is undersquare — the 3.4055" stroke exceeds the 2.9134" bore by 14.5% — a layout that trades peak RPM for leverage and torque low in the range. The 3.4055" stroke does not reach 4,000 ft/min of mean piston speed until about 7,050 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 4 cylinders displaces 22.7 ci (372 cc).
8.8:1 is low by modern standards and generally happy on regular pump fuel.
It is one of 10 engines in the E-series family, sitting between the 81.9 ci and 97.6 ci members. 4 factory variants share these dimensions, rated at 67 hp across 1980–1983.
| Displacement | 90.8 ci / 1.5 L |
|---|---|
| Bore | 2.9134" |
| Stroke | 3.4055" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 8.8:1 * |
| Bore/stroke ratio | 0.855 |
* Compression ratio from a single source; not yet cross-verified.
| Valvetrain | SOHC |
|---|---|
| Fuel type | gas |
| Advertised HP | 67 hp |
| Years | 1980–1983 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 1980 | EM net | 67 | — | — |
Factory specification sheet.
| Bore/stroke character | 0.855 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 3,406 ft/min — conservative for a street engine |
| Displacement per cylinder | 22.7 ci |
| Static compression | 8.8:1 — 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 | 67 hp | EM |
| 1981 | — | EM |
| 1982 | — | EM |
| 1983 | — | EM |
1 factory vehicle, 1980–1983. Each year opens that model's engine table.