How tight should intake manifold bolts be?
An oil leak may result if the vertical bolts are not tightened before the diagonal bolts on the lower intake manifold. Tighten the lower vertical intake manifold bolts to 115 inch-pounds (13 Nm), then tighten the lower diagonal intake manifold bolts to 115 inch-pounds (13 Nm).
What is the torque on the intake manifold?
Intake manifold bolts and head studs/bolts have to be torqued in a certain pattern and to a certain torque spec in order for your engine to work properly. Intake manifold bolts on SBC engines should be torqued to 30 lb-ft in a two-step sequence.
Do you have to Torque intake manifold bolts?
Technically, it’s only necessary to tighten the manifold fasteners correctly. Some experienced mechanics can do that without a torque wrench.
What is the torque on exhaust manifold bolts?
Every vehicle has different levels of torque necessary to properly tighten its bolts. The standard is to use 20 to 30 foot-pounds of torque.
How tight should exhaust flange bolts be?
Tighten the bottom nut of the rear cylinder head exhaust flange to 9-18 in-lbs (1-2 Nm). Tighten the top nut to 100-120 in-lbs (11.3-13.6 Nm).
Why do torque specs have a range?
Torque specs are listed as a range because it’s not critical to have an exact torque applied. If it was critical then some sort of quality control spec would also be given. But mostly a range is given so we don’t worry needlessly if we tightened a fastener properly.
How much torque does a 1/2 inch bolt have?
ASTM A449 / SAE Grade 5*
| Bolt Size | TPI | Tightening Torque (ft lbs) |
|---|---|---|
| Plain | ||
| 1⁄2 | 13 | 75 |
| 9⁄16 | 12 | 109 |
| 5⁄8 | 11 | 150 |
How much torque can a Grade 5 bolt take?
Tightening Torque Guide for Grade 5 & 8 Hex Cap Screws
| GRADE 5 | ||
|---|---|---|
| Coarse Thread | ||
| 1/4-20 (.250) | 2025 | 76 in lbs. |
| 5/16-18 (.3125) | 3338 | 13 ft lbs. |
| 3/8-16 (.375) | 4950 | 23 ft lbs. |