OEM head bolt torque to 74 in/lb

cre · 06-18-2010, 05:05 AM

Factory Head Bolt spec: 58ft lbs
(ISO Standard IIRC) 12mm x 1.25 fasteners (bolts, not studs) and ARP's required torque: 75ft lbs
(ISO spec IIRC) ARP required torque for studs: 90ft lbs

Header fasteners: 29ft lbs

Valve cover screws: 22INCH lbs

With a retorque on an old HAG there is always the danger of splitting a brittle jacket and creating a cavitation prone opening where there was none previously. I've only ever heard a couple people discuss this happening to them though and the odds are remote. You may look at it this way: If it's a stock HG... it IS going to leak eventually. The retorque simply may buy you more time. If you accept the inevitable there's really not any down side.

06-18-2010, 05:05 AM	#8
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Factory Head Bolt spec: 58ft lbs (ISO Standard IIRC) 12mm x 1.25 fasteners (bolts, not studs) and ARP's required torque: 75ft lbs (ISO spec IIRC) ARP required torque for studs: 90ft lbs Header fasteners: 29ft lbs Valve cover screws: 22INCH lbs With a retorque on an old HAG there is always the danger of splitting a brittle jacket and creating a cavitation prone opening where there was none previously. I've only ever heard a couple people discuss this happening to them though and the odds are remote. You may look at it this way: If it's a stock HG... it IS going to leak eventually. The retorque simply may buy you more time. If you accept the inevitable there's really not any down side. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->