Monday, March 3, 2014
Smallblock Chevy Torque Specs
The small-block Chevy is a compact eight-cylinder engine of cast-iron construction. Although Chevrolet used a V8 engine briefly in the 1920s, most of their cars from the late 1920s through the early 1950s were powered exclusively by inline six-cylinder engines. When virtually every other American car maker had an eight-cylinder engine to offer, the Chevy still had its six. All that changed in 1955 when the small-block V8 was introduced. This engine was designed with larger versions in mind, and several different displacements were manufactured until the 1990s, when the small-block was replaced with more modern engines. All parts of the small-block are fastened together and tightened to a specific torque, as this keeps everything together securely.
Internal Parts
The bearing cap retaining bolts on small-blocks with two-bolt 7/16-inch main bearing caps should be tightened to 70 foot-pounds. The outer bearing bolts on four-bolt 7/16-inch bearing caps should be tightened to 65 foot-pounds, while the inner bolts should be tightened to 70 foot-pounds. All four retaining bolts on four-bolt 3/8-inch bearing caps should be tightened to 40 foot-pounds. Connecting rod bolts with a measurement of 3/8 inch should be tightened to 45 foot-pounds, while 11/32-inch connecting rods should be tightened to 35 foot-pounds. Cylinder head bolts are tightened to 65 foot-pounds, while the screw-in rocker studs need to be torqued to 50 foot-pounds. The oil pump retaining bolts should be tightened to 65 foot-pounds.
External Parts
The threads on the exhaust manifold bolts should be coated with an anti-seize lubricant and tightened to 25 foot-pounds. The intake manifold gets tightened to 25 foot-pounds. The transmission bell housing bolts should be tightened to the block at 25 foot-pounds each. The center bolt on the harmonic balancer needs to be tightened to 60 foot-pounds. Spark plugs get torqued down to 20 foot-pounds. The flex plate on automatic transmission-equipped vehicles and the flywheel on manual transmission-equipped vehicles both get tightened to 60 foot-pounds.
Sheet Metal Parts
The small-block Chevys oil pan retaining bolts need to be tightened to 12 foot-pounds. The bolts attaching the timing cover to the front of the engine block get tightened to six foot-pounds, while the valve cover bolts require a torque of only three foot-pounds.
No comments:
Post a Comment