When the Vega first came out, its four cylinder was an all aluminumdesign with no iron liners. While revolutionary, the special coatingused to protect the cylinder walls from scuffing by the rings didn'twork, and these engines suffered from horrible cylinder sealing. Thesolution was a factory recall where the blocks were bored out so ironcylinder liners could be installed. With iron liners, the cylindersstayed sealed, and the engines ran pretty good. These engines also hadan odd valve cover design because of the placement of the valves and camfollowers.