When it comes to cylinder head fasteners, it’s crucial that you follow the recommended torque specifications and torque sequences. Torque specs vary depending on the fastener brand, lubricants, and other factors; however, the cylinder head torque sequence generally remains constant for a given engine.
To give you a quick reference of torque sequences, we’re rolling out a series of infographics for different engine makes. Today, we’ll look at cylinder head torque sequences for Ford V8, V10, and V12 engines (if you’re a Chevy person, click here).
(INFOGRAPHIC BY LORI SAMS)
Head Fastener Installation Tips
- Inspect and clean your existing head bolts if you’re re-using them.
- Use new fasteners on a high-mileage or high performance engine.
- Make sure your existing bolts aren’t torque-to-yield (TTY) — this type of fastener is designed to stretch and cannot be reused.
- Check bolts in a set against one another to ensure none are stretched or deformed.
- When using stock fasteners, check your service manual for proper torque specs.
- Check with the manufacturer when using aftermarket fasteners as the specifications will vary. These torque values are usually based on oiled fasteners.
- Lubricate the threads and underside of the bolt head with motor oil or aftermarket lubricant.
- Some manufacturers, such as ARP, recommend cycling the bolts to improving loading accuracy. This involves torquing the fasteners to about 50 percent of their recommended spec several times before reaching the final number.
- If you’ve had your cylinder heads resurfaced, you’ll need to check that your cylinder head fasteners don’t bottom out in blind holes.
- Use hardened steel washers when installing aluminum cylinder heads.
- Check the accuracy of your torque wrench and recalibrate, if necessary, before bolting down your cylinder heads.
I had no idea that there was a specific sequence for tightening that you were supposed to follow when it comes to tightening cylinder heads. I think it’s really important to know now though, because if you’re tightening them wrong, you could have some major issues on your hand in the event that something goes wrong. Thanks for sharing!
[…] You can see our torque sequence infographic for Chevy engines here, and for Ford engines here. […]