Headbolt retorque need advice

[mickgarvey]

Ive been looking around for information but havent found a solid answer. Im going to retorque my headbolts and here are my main concerns.

Do i loosen the headbolts slightly befor retorqueing?

Im going to let my car sit in around 60 degree weather with the hood open for 4 hours then hit it with the hose and let it sit an additional 2 hrs should this be sufficient?

I dont want opinions i want solid information obviously lol kind of important.

Thankd

 

[nick88]

Are they the stock headbolts?

If so, just torque them to 70-72ft/lbs, I would not want to mess with the seal of a stock head gasket and the risk of a blown head gasket going up even more.

 

[mickgarvey]

Yeah i was planning on it just need to have it verified whether or not I should because I heard it wont be an accurate re torque without first breaking the bolt loose.

 

[BrandonW]

i would also like to know the answer to this, i used arp studs torqued to 80 ft/lbs by what the instructions in the arp box said and a hks stopper metal hg

when i do the 5 heat cycles do you loosen them? or just torque back to 80 ft/lbs?

how long should you wait if the engine is fully warmed up?

 

[mickgarvey]

yes please we need someone with mechanical background to chime in

 

[jtamulis]

When I've done retorques, I back the nut off (ARP Studs), just a little, but free, then retorque to 5-ftlbs MORE then they were originally set at (75 goes to 80, etc.). ONE at a time, IN ORDER specifiec in the TSRM.

Jeff

 

[suprarich]

Yes, the fastener must be cracked loose to re-torque. You only need about a 1/4 of a turn loose. Remember, the fastener must be moving to read the correct torque. Do one at a time in order, do not loosen all of them at once.

 

[mickgarvey]

ok thanks, and by doing one at a time in order i shouldnt be worried about making sure the block is completely cold right?

 

[jtamulis]

Yep, make sure the motor is cold, as in it hasn't been run AT ALL that day.

Jeff

 

[mickgarvey]

alright ill be waiting for saturday then

 

[sixpatch]

Very helpful thread guys. Thanks!