davids2k

Hello, Im about to put my 2 heads together into my motor after getting rebuilt from machine shop but I could not find any torque specs anywhere on this forum or google. would anyone like to give me torque specs for the heads and the sequences of which order heads bolts goes in. other torque specs would be great too.

LScowboyLS

29 ft-lbs

here are the applicable pages from the 1996 Lexus factory service manual

davids2k

ssssssweeeeet! thanks youre a life saver!!

PureDrifter

iTrader: (10)

29 ft-lbs is NOT the final torque for the head bolts. 1uz head bolts are yielded on use so shouldn't really be reused.

the correct torque level is actually 29 ft-lbs on the first pass then an additional 90* tighter.

LScowboyLS

actually, it's not 29 ft/lbs. on the first pass, this is incorrect information

the correct method on the LS400, like on most all cars, is several progressive tightenings leading up to the 29 ft.lb specification "in several passes" is the phraseology the service manual uses, not "on the first pass" which quite a different meaning indeed.

Also, I didn't say 29 ft. lbs.was the final torque, hopefully this is not his first time torquing a head on a vehicle, and he knows that torquing down a cylinder head is always a progressive torquing. - Since he was enlightened enough to know there is a precise torque pattern/order, he has probably built an engine before.

but just in case he didn't know this, I provided him with the applicable service manual pages, where the several passes leading up to 29 ft. lbs. as well as final torquing of another 1/4 turn on each bolt after reaching 29 ft. lbs.is fully explained in the procedure, so we're all good!


the manual says not to reuse a cylinder head bolt if it doesn't meet torque specification or is broken or deformed, but they don't specify to use all new ones, so Toyota doesn't agree with you on this either, although I, myself, would probably use all new ones, given the critical nature of a head bolt, so this practice I think is good one.