What is the torque specification for tightening head bolts?
1. Tighten each bolt to 7-9 foot pounds of torque. 2, Tighten each bolt to 12-14 foot pounds of torque.
How much torque should a head gasket have?
Many cylinder heads require multiple torque sequences to achieve proper tension. For example, a 10-bolt cylinder head may require you to tighten them all first to 42 foot-pounds in a specified order, then to 75 foot-pounds in the same order. Improper sequencing or torquing of the bolts may result in damage.
What are the torque specs?
By definition, torque refers to the amount of rotational force at the point of application. When attaching a wheel to a vehicle, torque specifications are the amount of force recommended on the hardware to ensure proper installation. Following exact torque specifications matters for a number of reasons.
How do you find the torque spec?
Begin with the formula T = K x U x D x P, where T is the torque, K is a standard representing 1.33, U is the coefficient of friction, D is the diameter of the fasteners, and P is the necessary preload.
What order do you torque head bolts?
Normally you would tighten conventional head bolts in a crisscross pattern in three steps, to one-third, two-thirds, and then to the final torque. Stretch bolts are tightened in a torque-plus-angle sequence.
What are the torque settings for cylinder head bolts?
With the engine cold, tighten the cylinder head bolts, in sequence in 2–3 steps. Final torque on bolts 1–10 should be 65–72 ft. lbs. (88–98 Nm) and on bolts 11 and 12, 11–16 ft.
What is torque sequence?
Bolt tightening sequence, or torque sequence, is defined in the torque tightening procedure. Flange joints are torqued tight with the help of a torque wrench (manual or hydraulic). Torque bolts and nuts in a “CRISS-CROSS” sequence using a minimum of three torquing passes and the maximum bolt stress as defined.
What is the torque specs for Chevy 350 heads?
The Chevrolet 350 cylinder-head torque specification is 65 ft. -lbs. The intake installed onto cast-iron heads requires 30 ft. -lbs.
What is the head bolt torque?
A crucial component of engine building is setting the torque on head bolts. Torque refers to how tight a bolt should be. When setting the torque, reliance on the specifications set by design engineers is vital. One essential tool you must have is a good quality torque wrench.
What happens if you don’t follow the torque sequence?
Insufficient torque When you apply exactly the right amount of fastening force, you can rest assured that the bolt will transfer the ‘hits’ as well as the load of the belt to the bulk of the engine, which will absorb them. This, in turn, will lead to incorrect belt tension and, eventually, to belt and/or engine damage.
Are there different torque specs for cylinder heads?
Any aftermarket cylinder heads (such as Offenhauser, Edlebrock, and others) will call for different torque specs, even though the tightening sequence may be the same.
How much horsepower does a cast iron head have?
All manuals suggest that the mechanic coat the threads with a thread sealer before installation. 85 Horsepower V8 with Cast Iron Heads…………………………. 50-60 ft lbs 100hp (239 cu. in. V8’s) whether Ford or Mercury. Note: The specs apply to all Ford and Mercury Flathead V8’s of these years.
When to check torque on an aluminum head?
Aluminum heads call for lower torque specs and it is recommended that the mechanic re-check the torque after the engine has run up to temp and then cooled (in other words….after it has cooled from running). Some owners will re-check all flathead torque settings again after the first month of operation.
How often should I Check my Flathead torque?
Some owners will re-check all flathead torque settings again after the first month of operation. It is also suggested with aftermarket heads that you “clay” the heads (place modeling clay in the chambers where the valves rise) to check valve clearance before the actual torquing of the studs/bolts. A clearance of .040 is a minimal amount.