When working on a small block Chevy (SBC) engine, it’s crucial to adhere to the specified torque values for all bolts and components. Overtightening can cause damage to threads, bolts, and other parts, while undertightening can lead to loose connections and potential failures.
General Torque Specifications for an SBC Engine
The following table provides general torque specifications for various components of an SBC engine:
Component
Torque Value
Cylinder Head Bolts
65-78 ft-lbs (cast iron heads) / 45-55 ft-lbs (aluminum heads)
Intake Manifold Bolts
23-30 ft-lbs (cast iron manifolds) / 18-25 ft-lbs (aluminum manifolds)
Exhaust Manifold Bolts
25-35 ft-lbs (cast iron manifolds) / 15-20 ft-lbs (aluminum manifolds)
Always use a torque wrench to ensure accurate tightening.
Apply a small amount of thread sealant to cylinder head bolts and intake manifold bolts to prevent leaks.
Torque all bolts in a crisscross pattern to avoid warping.
Refer to the manufacturer’s instructions or a repair manual for specific torque values, as they may vary slightly depending on the model and year of your SBC engine.
What is the torque specification for cylinder head bolts on a small block Chevy?
The torque specification for cylinder head bolts on a small block Chevy is 30-35 ft-lbs in three stages of tightening (15-20, 25-30, 30-35).
What is the torque specification for intake manifold bolts on a small block Chevy?
The torque specification for intake manifold bolts on a small block Chevy varies depending on the material of the intake manifold and the cylinder heads. For aluminum with aluminum heads, the torque is 20-25 ft-lbs. For aluminum with iron heads, it’s 30-35 ft-lbs. For iron with aluminum heads, it’s 25-30 ft-lbs, and for iron with iron heads, it’s 35-40 ft-lbs.
What is the torque specification for exhaust manifold bolts on a small block Chevy?
The torque specification for exhaust manifold bolts on a small block Chevy is 25-30 ft-lbs in two stages of tightening (15-20, 25-30).
Component
Torque (ft-lbs)
Additional Notes
Cylinder Head Bolts
30-35
Tighten in three stages of 15-20, 25-30, and 30-35
