Bore, stroke, displacement and compression for all 5 Hyundai Smartstream engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 152.4–212.2 ci |
|---|---|
| Cylinders | 4, 6 |
| Bore | 3.484–3.622" |
| Stroke | 3.425–3.996" |
| Compression | 10.0–13.0:1 |
| Advertised power | 191–375 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| G6DS | 212.2 ci | 3.622" × 3.4252" | 11:1 | 375 |
| G4KR | 152.6 ci | 3.4843" × 3.9961" | 10.5:1 | 290 |
| G4KM | 152.6 ci | 3.4843" × 3.9961" | 11.3:1 | 191 |
| G4KN | 152.4 ci | 3.4843" × 3.9961" | 13:1 | 191 |
| G4KP | 152.4 ci | 3.4843" × 3.9961" | 10:1 | 281 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 10:1 to 13:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
The family mixes oversquare and undersquare designs, so members behave quite differently despite sharing a name.
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.