Motorization site

General characteristics
* Type: 18-cylinder supercharged two-row radial engine
* Bore: 156 mm (6.142 in)
* Stroke: 156 mm (6.142 in)
* Displacement: 53.671 L (3,275.2 in³)
Components
* Valvetrain: One intake and one sodium-cooled exhaust valve per cylinder
[...]

By 1943 the ultimate development of the new bomber program, the B-29, was flying. However the engines remained temperamental, and showed an alarming tendency of the rear cylinders to overheat, partially due to excessive clearance between the cylinder baffles and the cowl. A number of changes were introduced into the aircraft production line in order [...]