Ford Y-block Engine - 239

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The first Y-block on Ford automobiles was the 1954 239 in³ (3.9 L) Ford engine; known for its deep skirting, which causes the engine to resemble a Y. Rated at 130 hp (97 kW), it replaced the 239 in³ (3.9 L) flathead which was rated at 106 hp (79 kW). The Y-block was considered a major advancement over the flathead. It is known for having oiling problems in the rocker shafts due to the fact the oil first went to the crankshaft bearing, then to the camshaft bearings, then to the rocker shafts. This problem plagued the entire Y-block family and could be remedied by running a copper line from the oil pump and then to the rocker shafts.

The oiling problem was caused by the passage from the center cam bearing to the cylinder head being offset by an inch and too small. The motor oils of the era were low in detergents, but high in coke; when combined with short trips and infrequent oil changes, this led to blockage of this passage. This left the lower end with ample oil while the rocker shaft assemblies literally burned up. The external oiler kit essentially provided oil to the rocker shafts from the oil pressure port on the outside of the engine.

A quick reference to the engine specifications for 1955-57 will show the Ford V-8s ahead of the Chevrolet counterparts in displacement, horsepower and torque. The real enemy of the Y-block was its displacement limit. The original architecture was very small and tight. Even with the benefit of today's technology (aftermarket rods and stroker cranks), the real limit of a Y-block is about 348 in³, while the Chevrolet could be modified well past the factory limit of 400 in³. The ever-increasing size and weight of the standard passenger car, the added parasitic losses for accessories (power steering, power brakes and air conditioning), cheap gasoline and the horsepower race all caused Ford to outgrow its first OHV V-8 engine. It is interesting to note that both Ford and Chevrolet went to optional "big block" engines for 1958, 352 in³ (5.8 L) at Ford compared to 348 in³ (5.7 L) at Chevrolet.