Hello folks,
what the rule of thumb with head bolts? I'm rebuilding my block at the moment and wondering if I need to replace all of them. Some of them show corrosion in the shank and thread area's, I have seen some rebuilds where they have not replaced them, maybe due to the risk of snapping one I suppose.
any thoughts?
cheers,

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I would replace any that seem to be seriously corroded so the stud is thinner. Although 100% security says replace all, I think that any that look OK or have just light rust will be fine, unless you are building a race engine.

 

I'm building a V12 now and will only be replacing 1 stud and that broke. Most of them do have some corrosion but not to the point where the strength is compromised, they have been plated to prevent further corrosion.

As Greg said if they are thinner then replace them.

 

Hi Warren , sorry to give you more typing . What are you plating the bots with and will the extra thickness be ok as far as fitting is concerned.

 

Warning !

Hydrogen embrittlement is a risk, if high strength steel is electrolytic plated. It's not a coincidence that 12.9 bolts is delivered 'black'

 

Norman Lutz has built enough high performance Jaguar V12's and I6's to know what works, he had them plated.

I'll ask him what they were plated with

 

Plating will be OK, if the bolt strength is not extreme.