Torquing ARP crank bolt?

LarsD · Dec 23, 2010

I'm planning on removing my U/D pulleys and replacing them with stockers on my Cobra. While I had it apart I was going to replace the TTY bolt with an ARP crank bolt. Since it isn't (I assume) a TTY bolt, what should I torque it to? I know my 91 was 90-ish ftlbs. Also I figure I don't have to go through that goofy torque-loosen-torque business. I figure someone here has to have done this at some point.

Thanks

trinity_gt · Dec 23, 2010

I believe it's around 124 ft-lbs. Use ARP lube on the threads and under the bolt head. If that's not available, use some motor oil.

LarsD · Dec 23, 2010

Little higher then I expected, but that is probably it. Might I ask how you found that out?

trinity_gt · Dec 23, 2010

Sean Hyland quoted a figure of 125 ft-lbs on page 20 of his book How To Build Max-Performance 4.6 Liter Ford Engines. He even gives the ARP bolt #: 156-2501. (He uses 124 in the section at the back when building the 4V motor...)

Having said that, ARP recommends a little lower if you use their lube. They recommend 112 ft-lbs on a 200,000psi bolt like the 156-2501 (M12x1.5). See:

ARP-bolts.com | ARP - World-leading Fastener Technology

He may have used the higher value because he used SAE30 motor oil as a lube and not the ARP stuff.

Go for the lesser value first. If you experience any misfire engine codes it may be a sign that the dampener is not tightened quite enough. It's always safer to sneak up on the correct value rather than shoot for the moon on the first go and risk the crank snout threads.

LarsD · Dec 23, 2010

trinity_gt said:
Sean Hyland quoted a figure of 125 ft-lbs on page 20 of his book How To Build Max-Performance 4.6 Liter Ford Engines. He even gives the ARP bolt #: 156-2501. (He uses 124 in the section at the back when building the 4V motor...)

Having said that, ARP recommends a little lower if you use their lube. They recommend 112 ft-lbs on a 200,000psi bolt like the 156-2501 (M12x1.5). See:

ARP-bolts.com | ARP - World-leading Fastener Technology

He may have used the higher value because he used SAE30 motor oil as a lube and not the ARP stuff.

Go for the lesser value first. If you experience any misfire engine codes it may be a sign that the dampener is not tightened quite enough. It's always safer to sneak up on the correct value rather than shoot for the moon on the first go and risk the crank snout threads.

Totally with you on that, I don't like breaking stuff. You have been an immense help, thank you!

Torquing ARP crank bolt?

LarsD

trinity_gt

LarsD

trinity_gt

LarsD

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