Removing head studs ?

Here is the question, if there was discoloration and now there is none and it took sand paper to remove it then was material removed? Seems solvent and scotch brite would have done it if not.

Little stubborn stain here, a little more sanding there, uneven pressure here, little more pressure there 10 to 15 RA is not much... It takes huge nuts to take sandpaper block by hand to a ferrari block. Hats off to you!

 

I'm talking about the surface finish, not the grit of the paper. I seriously doubt you did any damage. I'd be more concerned about the grit of the sandpaper getting into the bores....

 

I would not have used that tool but I agree with you. Those tiny marks, on a hardened stud, are not going to cause problems.

 

Im in the middle of studs not being ruined.
Without knowing their strength, and design criteria, how can we just say ther are not ruined.
The fact that they are studs and designed to be in tension helps
The fact that althought i have not built hundreds of engines i have been involved with a few, and never seen a stud fail except when tring to get them out.
Thinking out loud if new studs would not get stuck in as easy in the future, i would likely change them just because i was keeping the engine a long time.

 

Removing the head studs to prepare the block for a new head gasket is not necessary. This im sure would have been outlined in the 1st response if the reason for removal was included in the first place. Specialist experience is required when taking on a job of such magnitude.

 

No. Not a silly question. Studs don't need to be tight or firmly set. As long as they don't rotate while putting on a head nut, thats all you need.

 

Ferrari head studs never ever break in the middle of the shank.

100% of the time they fail at the base of the upper thread. I always measure to see if there is any hour glassing.

 

Thanks much, Brian. I appreciate your sharing these details of the craft.

 

I'll be honest I am not sure what all the discussion about the studs is. With all the work and cost why not just replace them with ARP or what not, the cost of new studs wold be negligible and you never have to give it a second thought.

I always thought if you remove them you don't reuse them anyhow, maybe that's just a rule of thumb but its a good one and were talking a few hundred bucks.. Not even sure how its a question.

 

Actually very expensive. I do have ARP make them for me but for not much different than the $40+ each for a Ferrari stud. X 20 it isn't cheap.

Odd size stud and ARP has to do a special run. I don't think anyone else uses 11 x 1.0 and then whatever the bottom half is.

 

Do you reuse them if you remove them from the block?
It is acceptable practice if they are in good shape so I know for future reference?

 

No reason to not reuse them if they are not damaged.

 

OK good to know.

 

Maybe Brian can explain why he has them made then.
Or why he takes them out to begin with.
I guess you may have no choice if the head was damaged and needed repair.

Still unsure how the consenses is that studs are ok without knowing the factual metallurgy and design requirements

 

I'm sure undamaged studs never fail in the middle of the shank.
But these now have indentations on the surface.

Although it is hard to judge from a picture how deep and sharp they are, as Fatbillybob pointed out these are stress risers, and a prime starting point for fatigue cracks.
And these studs are subjected to both thermal and mechanical cyclic loads.

 

He was right in saying that. Studs really only get removed to replace them or do machine work that requires them to be out of the way. Never damaged a block getting them out but it can turn into a nightmare in some cases.