Tiny but tough! With only a 2.5-inch bore and a 2.25-inch stroke, this four prefers the higher-rpm ranges. Known as the CIBA (Cast Iron Block Assembly), the 44ci engine, and its later derivatives, actually has an extensive racing history in a variety of sports and race cars. It does not have a removable cylinder head—rather the combustion chambers, valve seats, cam supports, ports and cylinders are one casting, and the crankcase is another. In both the early and later cast-iron engines, the crankcase is aluminum. In the early “Tin Block” engines, the cylinders and upper parts were stamped heavy sheetmetal that was copper-brazed (hence the nickname “CoBRA”) into an assembly. The cast-iron CIBA engine debuted in 1949 and was only about 30 pounds heavier than the CoBRA.