Bore, stroke, displacement and compression for all 3 Hyundai Beta engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 109.8–121.9 ci |
|---|---|
| Cylinders | 4 |
| Bore | 3.228" |
| Stroke | 3.346–3.681" |
| Compression | 10.0–10.1:1 |
| Advertised power | 130–140 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| G4GF | 121.9 ci | 3.2283" × 3.6811" | 10:1 | 140 |
| G4GC | 120.5 ci | 3.2283" × 3.6811" | 10.1:1 | 138 |
| G4GM | 109.8 ci | 3.2283" × 3.3465" | 10:1 | 130 |
Every engine here shares a 3.2283" bore; displacement varies by stroke alone, which is the signature of a family built on one block with different cranks.
2 of 3 are undersquare — stroke larger than bore, favouring torque low in the range.
Each engine page carries rod ratio, mean piston speed, bore/stroke character and cylinder head specs where published, and links into the calculators with its dimensions already filled in.