See other engines in this family
Hyundai Sirius specs: 1.8L (109.8 ci) 4-cylinder, 81 x 88 mm (3.1890 x 3.4646 in) bore and stroke, 9.2:1 compression. Rated 105-113 hp. SOHC.
The Hyundai Sirius is undersquare — the 3.4646" stroke exceeds the 3.189" bore by 8.0% — a layout that trades peak RPM for leverage and torque low in the range. The 3.4646" stroke puts mean piston speed at 4,000 ft/min around 6,950 RPM, which is where a production bottom end is generally considered at its limit. Each of the 4 cylinders displaces 27.5 ci (450 cc).
9.2:1 on aluminum heads is low by modern standards and generally happy on regular pump fuel.
It is one of 2 engines in the Sirius family, the smallest at 109.8 ci. 2 factory variants share these dimensions, rated from 105 to 113 hp. Factory fitments include the Hyundai Elantra, Hyundai Sonata, Hyundai Stellar.
| Displacement | 109.8 ci / 1.8 L |
|---|---|
| Bore | 3.189" |
| Stroke | 3.4646" |
| Cylinders | 4 |
| Compression ratio | 9.2:1 |
| Bore/stroke ratio | 0.92 |
| Block material | cast iron |
|---|---|
| Head material | aluminum |
| Valvetrain | SOHC |
| Fuel type | gas |
| Advertised HP | 105–113 hp |
| Bore/stroke character | 0.920 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 3,465 ft/min — conservative for a street engine |
| Displacement per cylinder | 27.4 ci |
| Static compression | 9.2:1 — 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 |
|---|---|---|
| — | 105 hp | G4CN |
| — | 113 hp | G4CM |