Dodge hemi small block

Dodge did not have a V8 engine until one was developed specifically for the line in 1953 based on the 1951 Chrysler hemi design, but down-sized for these smaller cars. They have the smallest bore center distance of any hemi engine at 4.1875 in (106.4 mm). They do not share any major dimensions or components with the larger Chrysler and DeSoto hemi engines, or the Plymouth polyspheric ("poly") A engines. From 1955-58 lower performance versions of the Dodge hemi were introduced by substituting less complex poly (single rocker shaft) heads and valve train parts, including one variant only built as a poly (259"). These were used in low-line 1955-58 DeSotos and Dodges, and 1955-56 high-line Plymouths.

241

The Dodge introduced the 241 cu in (3.9 L) version in 1953. Bore was 3.4375 in (92 mm) and stroke was 3.25 in (83 mm). It produced just 140 hp (104 kW).

270

The 270 cu in (4.4 L) was used in the 1955 and 1956 Dodge high-line (premium) vehicles. Bore was 3.625 in (92 mm) and stroke was 3.25 in (83 mm).

315

In 1956, the displacement was raised to 315 cu in (5.2 L) with the same bore and a longer 3.80 in (97 mm) stroke and a taller raised-deck block.

325

In 1957-58 the bore was increased to 3.6875 in (94 mm) to 325 cu in (5.3 L) with the same 3.80 in (97 mm) stroke.