In what order should cylinder head bolts be removed?

In what order should cylinder head bolts be removed?

Part 1 of 3: Getting to the head bolts

1. Materials Needed.
2. Step 1: Drain the oil and coolant.
3. Step 2: Clean valve cover.
4. Step 3: Remove valve cover.
5. Materials Needed.
6. Step 1: Rocker arm and rocker removal.
7. Step 2: Remove the pushrods.
8. Step 3: Loosen head bolts.

When tightening cylinder head bolts what sequence should be used?

In general, the correct sequence is to insert one bolt then insert the next bolt in a location as nearly opposite to the first bolt as practical, insert the third bolt halfway between the first two on one side and the fourth on the opposite side, and continue in this manner until all bolts are inserted.

Why are cylinder head bolts loosened and tightened in a specific sequence?

Tightening a bolt stretches it, while pulling the head and block together. These bolts elastically deform and return to their original dimensions when loosened. Friction between the bolt head, its washer, and the cylinder head isn’t consistent. 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.

When do you remove the cylinder head bolts?

Most of the time the cylinder head should only be removed when replacing the head gasket or performing a engine rebuild. At any point during removing the head bolts, if questions arise, Ask a Mechanic for some useful, quick advice. This article originally appeared on YourMechanic.com as How to Remove Cylinder Head Bolts.

What happens when torque is removed from an engine bolt?

In this phase, the bolt is stretched as torque is applied to it, but should the torque be removed the bolt will return to its original length. It is important to remember that in the elastic phase, the bolt will not provide sufficient clamping force to hold the cylinder head down reliably.

Why are engine bolts no longer held together?

However, new engine designs that used disparate materials, such as cast iron for the engine block and aluminium for the cylinder head (s), meant that conventional bolts could no longer hold these engines together, since cast iron and aluminium expand and contract at vastly different rates.

Why are cylinder head bolts torqued from the inside out?

For squirrel, The reason heads bolts are torqued from the inside out is to allow the gasket to expand outward as we tourque. If we were to torque the outside bolts first we would “trap” the gasket thus not allowing it to spread. Click to expand…