So, my engine's off to the machine shop (engine head and block), and I was asked if these engines needed new engine bolts with this kind of work being done. I didn't have an answer for the machinist, so here I am asking that same question.

 

Here's the answer from the last time you asked:
https://www.zdriver.com/forums/280zx-s130-forums-77/so-shes-off-machine-shop-19830/

 

I can't remember if this question was asked recently on this forum or if it was HybridZ but, either way the answer was no, you should be able to reuse almost all of the bolts including the head studs but, if you can afford it, would be best to go ahead and replace those as well.

Also I think it was mentioned to be sure that the bolts have a light coating of oil on them as you thread them back in when you put everything together, might've been just the head studs you do that way though.

 

gawd.....I forgot I had asked that question before, my bad.

 

hahaha

 

Thats a good idea with any bolt thats going to require a specific torque. But parts like the head bolts are sensitive to torque specs so oiling those usually gets stressed more then other bolts.

 

The reason you want to lubricate the threads is without it, in the neighborhood of 95% of the torque you're trying to apply to the bolt is being used to overcome the friction on the threads.

With the lubrication, much more of the torque is being applied to the pieces you're trying to bolt together and you'll get a much more accurate torque setting that way.