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Bird Droppings on Y-block Engines
The Ford y -Block used in all Early Birds was unique with it's extremely rigid extended or deep skirted small block design, as the bottom block face extended 2 3/4" below the crankshaft centerline, much like H. D. diesel engines. This combined with its short stroke, high compression, overhead valve configuration marked the demise of the "flat-heads" (Altho, Chuck Hills says-"The flat-heads will rise again").
There is good reason for the countless loyal y -Block enthusiasts as y -Blocks were designed for maximum possible structural rigidity with a practically indestructible bottom-end, while the competition had a history of lower-end block warpage, with a sag of as much as 1/16" in an engine and transmission assembly.
The pushrod chambers were also skirted and gusseted to increase the rigidity and the cylinder head bolt bosses were formed in the block walls instead of next to the cylinder boxes which prevented cylinder bore distortion. The cylinder walls were unusually thick for rigidity and were attached only at the top and bottom decks allowing coolant to completely surround them.
Structural rigidity was also built into the heads. Combustion chambers with maximum quench areas were designed to accommodate at least 12:1 compression ratios (altho 9.7:1 was the highest used) for greater efficiency. The combustion chamber design provided more even burning of the air-fuel mixture, minimize detonation and reduced octane requirements (it's rather interesting-the Chevy V8 did not handle compression ration increases well).
The y -Block used integral valve guides to achieve lower
valve operating temperature by transfer of heat from the stem to the head and to the coolant, reducing valve stem temperatures from 725 degrees to 600 degrees F, and max head temperatures from 1550 to 1330 degrees F {Use of separate guides provided an insulation barrier). The valves had rotators to give longer valve face life. The cam was chain driven using mushroom type solid lifters, with tapered cam lobes for tappet rotation.
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