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cylinder head bolts retorque


kully 560

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Torquing a fastener requires that you have clean threads (male and female) and correct lubrication of the threads and the clamping surface around the bolt head/washers according to the manufacturers (bolts) specifications if you are going to get ANY prayer of getting an accurate torque. You can remove a bolt and clean its threads, and grease it up, but how are going to do prep the head hole with the head on?

Long story short, if you have a leaking head gasket, then sure, what’s the harm in trying a bolt re-torque  first, but without some indication of problems, why in the world would you poke a bear? Ne-touche-pas!

 

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well you make a point , but why would datsun recommended a cylinder head retorque after a valve adjustment.  do you think the dealers back then pulled the head? this is a 2 sided coin ? I guess if I do not remove the bolt and retorque to 60 lbs and nothing happens then nothing gained nothing lost make sense. I would just like to see why they recommended this at  every valve adjustment , were they expecting things to get loose?

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I agree with zKars. If its not broke, don't break it. There are a great many recommendations in the FSM, some I do, some I dont. Our modern head gaskets may not require it, the new headbolts might not require it. I can think of a few reasons it might have been SOP in the 60's but not now. In my might there is no upside to retorquing, only downside...

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Is there a difference here in definition between re-torquing and checking the torque?

 

My engine builder recommended that I “check” the torque on the first couple of valve adjustments in the first 1000 miles or so of my freshly built engine and then put the torque wrench down, take my hands off and back away slowly!!!

 

IMHO there is nothing wrong with setting your torque wrench at 40lbft as suggested and letting it click out (beep if electronic) to give you peace of mind. If the engine is built properly and with a decent head gasket then they shouldn’t be loosening. Some lesser head gaskets, I am told, “bed in” - which is probably the logic behind it. Even with a decent gasket, I am in the paranoid camp ;)

 

I even do this to my load bearing bolts with yellow paint, so yeah, paranoid!

 

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13 hours ago, kully 560 said:

hi again siteunseen , I was not thinking about removing the bolts, I was just going retorque them . do you think I should remove them and anti-seize ? [I do not want to brake the seal even 1 bolt at a time] and thanks for the bolt sequence !!!

Perhaps when the FSM was issued Nissan wasn't thinking about 50 yrs in the future with its recommendation of a retorque.  With an engine that has been sitting for 30 yrs there is the distinct possibility of rust forming on the head bolt threads.

Retorquing  on a realitivly fresh engine wouldn't bother me at all but I sure wouldn't want to do that on an old engine, they are set in their ways so to speak.

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11 hours ago, AK260 said:

.

I decided to leave well enough alone as from reading the consensus from ever body. but I did retorque my header bolts and intake today as is seems some of the header bolts were a little loose. I also decided to remove the heat shield and paint it with vht aluminum 550 degree paint , It needed it and looks a lot better . thanks for the support from every body great forum!!!!!!!

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  • 2 weeks later...

I always check the headbolts after running the valve adjustment. Set the torque wrench to the specified torque, and pull on each bolt, following the sequence specified in the manual.  Not trying to make them tighter, simply checking that they are all tight. Occasionally one or two will turn a bit, but generally they are OK.

Just like rechecking wheel nut torque.

Easy, squeezy, no pain, no stain.

 

 

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