OEM head bolt torque to 74 in/lb

907mge · 06-18-2010, 02:18 AM

Even so,I thought the stock head bolt torque is 58 ft/lbs not 54 and where do you get a number like 74. And there are no header bolts. There are studs though.

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.

wstanek · 06-18-2010, 02:09 PM

Quote:

Originally Posted by 907mge

Even so,I thought the stock head bolt torque is 58 ft/lbs not 54 and where do you get a number like 74. And there are no header bolts. There are studs though.

u knew what i meant just what is he talking about in relation to what ur talking bought

rob87 · 06-18-2010, 04:42 PM

My bad guys. It's not in/lb but ft/lb. I was just wanting to know if the oem headbolts/studs can take a retorgue of 70+ ft/lb. I'm new at the supra engine, even though I've had my car for about 10 yrs. I haven't had to do much with it after I had the engine swapt out with a less mileage one until now.

Thanks for all the tips and corrections. This forum is great!!!!

06-18-2010, 05:05 AM	#2
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 --->

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06-18-2010, 02:18 AM	#1
907mge 20psi boost Join Date: Dec 2009 Location: Harrisburg Posts: 759	Even so,I thought the stock head bolt torque is 58 ft/lbs not 54 and where do you get a number like 74. And there are no header bolts. There are studs though.

06-18-2010, 04:42 PM	#4
rob87 Stock Join Date: Apr 2010 Location: Belvidere IL Posts: 27	My bad guys. It's not in/lb but ft/lb. I was just wanting to know if the oem headbolts/studs can take a retorgue of 70+ ft/lb. I'm new at the supra engine, even though I've had my car for about 10 yrs. I haven't had to do much with it after I had the engine swapt out with a less mileage one until now. Thanks for all the tips and corrections. This forum is great!!!!