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Ford Racing Catalogue Web

ENGINE BUILDING TIPS AND SPECS VALVE SPRINGS AND THINGS ROCKER ARMS AND STUDS Valve springs are a critical part of valve train 429 BOSS, FE engines and some 4-cylinder operation. They’re designed to exert a specific rocker arms are shaft-mounted, while others load at a specific installed height, thus spring are individually mounted (in several ways), as selection and installation are important. A single shown in the illustration. A non-adjustable stud spring is generally used for stock engines. Dual or is used in production engines with hydraulic triple springs are often necessary for performance cams. Mechanical camshafts require rocker arm applications to increase the load for a given adjustment to set valve lash (hydraulic cams with installed height. If installed height isn’t sufficient anti-pump-up lifters also require adjustment). to handle camshaft lobe lift, coil bind may occur. Installed spring height is the distance from the This is a conventional rocker arm with close- spring seat to the bottom of the valve retainer. tolerance slot in head to guide push rods and Shims can be used under the spring to change maintain rocker arm alignment. Can be used spring height. If installed under stamped seat, with mechanical or hydraulic camshafts. shims and seat must have same outside diameter. USAGE: All 289 high-performance and Spring seats on most production engines consist 1963-1966 1/2 standard 289. of a boss machined in the head, on which the spring pilots. On stock performance engines (302 BOSS, 351C BOSS and HO, 429 CJ/SCJ and BOSS) the head is flat and the spring sits in stamped spring seat. Ford Racing offers spring seats for use with The illustration above is typical of Ford Racing aluminum cylinder heads to prevent 351C-351M-400 canted valve engines damage to the spring seat area. (429-460 engines are similar). The rocker arm is mounted on a slotted pedestal, moves on a “sled” fulcrum and is retained by a bolt. 351C BOSS engines use the 302 BOSS type valve train (also used on 429 CJ/SCJ), 1968-1972 429/460 with hydraulic camshafts use a screw-in positive Shown here is a “rail” rocker arm with “loose-fit” stop stud. 1973 and later 429/460 have the hole in cylinder head for push rods. The U-shaped 351C-type slotted pedestal. rocker arms maintain alignment. Can only be used with hydraulic camshafts. USAGE: 1966 1/2-1968 standard 289 1968-1976 302 and 351W. Here is a modified valve train to convert rail rocker arm design for mechanical cam. Requires conventional rocker arms, guide plates, hardened push rods (they rub on plates) and threaded adjustable rocker studs. Requires different guide plate than the one used with A modified pedestal is used on 1978 and later a similar 302 BOSS setup. 302/351W engines. A stamped fulcrum guide USAGE: 289/302/351W with mechanical camshaft. is used with each pair of rocker arms. For important information about the proper usage of performance parts, please see page 14. See pages 286-292 for important safety, emissions and warranty information. www.fordracingparts.com 81


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