Bore, stroke, displacement and compression for all 13 Volkswagen Air-cooled Flat Four engines, compared side by side. Free spec reference.
| Displacement | 69–96.6 ci |
|---|---|
| Cylinders | 4 |
| Bore | 2.953–3.366" |
| Stroke | 2.520–2.716" |
| Compression | 5.8–7.5:1 |
| Advertised power | 30–60 hp |
| Years | 1949–1979 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 1600 | 96.6 ci | 3.3661" × 2.7165" | — | — |
| 1600 | 96.6 ci | 3.3661" × 2.7165" | 7.5:1 | 57–60 |
| 1600 | 96.6 ci | 3.3661" × 2.7165" | 7.3:1 | 46–60 |
| AJ | 96.6 ci | 3.3661" × 2.7165" | 7.3:1 | 48 |
| 1500 | 91.1 ci | 3.2677" × 2.7165" | 7.5:1 | — |
| 1500 | 91.1 ci | 3.2677" × 2.7165" | 7.5:1 | 53 |
| 1300 | 78.4 ci | 3.0315" × 2.7165" | 7.3:1 | — |
| 1300 | 78.4 ci | 3.0315" × 2.7165" | 7.3:1 | 50 |
| 1200 | 72.7 ci | 3.0315" × 2.5197" | — | — |
| 1200 | 72.7 ci | 3.0315" × 2.5197" | 6.6:1 | 36 |
| 1200 | 72.7 ci | 3.0315" × 2.5197" | 7:1 | 40 |
| 1100 | 69 ci | 2.9528" × 2.5197" | 5.8:1 | — |
| 1100 | 69 ci | 2.9528" × 2.5197" | 5.8:1 | 30 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 5.8:1 to 7.5:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
All are oversquare — bore larger than stroke, which favours revs over low-end torque.
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.