Bore, stroke, displacement and compression for all 2 Chrysler 378ci engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 378 ci |
|---|---|
| Cylinders | 8 |
| Bore | 4.070–4.090" |
| Stroke | 3.580–3.630" |
| Compression | 9.6–12.5:1 |
| Advertised power | 600–700 hp |
| Years | 2015–2021 |
| Cylinder head data | 2 of 2 engines |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Chrysler 378ci · 4.090" × 3.580" · 9.6:1 | 378 ci | 4.09" × 3.58" | 9.6:1 | 600 |
| Chrysler 378ci (2021) · 700 hp | 378 ci | 4.07" × 3.63" | 12.5:1 | 700 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 9.6:1 to 12.5:1, 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.