Ford Windsor Engine - Overview

Overview

The small block Ford engine uses a thin-wall cast iron block with a separate timing chain cover, made from aluminum. This feature differentiates it from later Cleveland, or 351-series engines, that use an integrated timing cover, cast in the block. All Windsors use 2-valve per cylinder heads regardless of whether they are "2V", "4V", or fuel-injected models. The 2V & 4V designations referred to the number of venturi (or barrels) in the carburetor, not valves per cylinder. The valves are in-line and use straight 6-bolt valve covers. Another simple differentiation between the Small Block and "335" Cleveland series is the location of the radiator hose — the Windsor routed coolant through the intake manifold, with the hose protruding horizontally, while the Cleveland had the radiator hose connecting vertically to the engine block. The Cleveland and later "Modified" engines used a canted valve design, allowing for larger valves within the same 4" bore. Something worth noting was the fact that the Ford Engineers designed the Cleveland heads with the same bore spacing and head bolt configuration making it possible (with some light machine work) to bolt Cleveland heads to the Windsor block and in 1969 they did just that creating the Boss 302.

The oil routing in the engine block is unique in that a third passage is drilled parallel to the tappet passages. This passage ensures that oil reaches the main and cam bearings before the tappets, reducing the likelihood of lubricant starvation of the bearings (unlike the 351 Cleveland and the 385 series). The tappets are fed from an inverted 'V' passage cast in the rear under the intake manifold that connects with this passage and is sealed with a steel cap. The third oil passage is visible from the rear of the block with the transmission components removed. It is under and slightly right of the right bank tappet passage. The tappets on the left bank are the farthest from the oil pump and are last to be pressurized by oil upon a dry start. This gives an impression that there is insufficient lubrication, but this is normal and the noise ceases after several seconds of operation.

With the exception of the 289 HiPo, Boss 302 and 351W, all connecting rods use the same 5/16 in. dia. bolts. The rod forgings had undergone some changes throughout its history. The 221, 260 and early 289 (C2OZ-A and C3AE-D) rods used an oil squirt hole to lubricate the piston pin and rings. The oil squirt hole was discontinued in 1964. The same forging continued to be used up to 1967 and all were the same length (5.155 in.). The 302 used a shorter beam (C8OE-A 5.090 in.) but used the same cap up to 1970. In 1971 the cap design was changed from flanged to flat (D1OE-A). This was changed back to the flange design in 1988 due to fatigue failures from increased power output of fuel injection and continued until the end of production. The 289 HiPo and Boss 302 were the same length (5.155 in) used heavier beam and cap forgings and 3/8 in bolts but were machined differently. The former used square head bolts and square cut and the latter were spot faced for 'football head' bolts.