Godamm cylinder head exhaust studs

[914bob]

Hi, anybody got any magic solutions to preventing seizing of nuts on these studs so that they dont wind out when attempting to undo (stripping fragile alluminium threads with them) - or, worse still, shearing off. Brass nuts, stainless? What do you do?

Putting a spanner to these nuts is always a scary prospect - but the nature of the car seems that we need to more than most.

[swapped]

I was just glad when mine came out whole or snapped leaving a worth-while stump I could get the stud extractors onto - either option was fine as it gave me the opportunity to replace them all with spanky new ones - cheaper from a Porsche dealer than VW or a Porsche 'specialist' (neither of whom had never heard of stepped studs, and couldn't quite grasp what they might be)!

The best tip I got (from a very experienced Jag-restorer) was to make a thread cleaner using the best of the removed studs, and taking the time to use it (carefully) on all the head holes - it makes a huge difference when you can screw-in a new stud cleanly, with no resistance from grit or crossed-threads as you go.

I used 'racer' under-sized (11mm) stainless nuts to reassemble, and of the problems my car has, a leaky eahaust is no longer amongst them

Carl

[Nige]

I have little advice on how to remove them other than patience.

What I would suggest is have some 11mm Hex bar cut down to 40-50mm lengths that have a matching internal thread for the studs. The extra length covers all the thread and prevents any exposure to rust, you can then also lather the whole thread up with copper grease. The extra length also allows better access for spannering.

I bought the Hex bar for a couple of quid and my local garage machined and tapped the bar into 50mm long nuts for a pavorotti.

[fourteener]

One of my head studs kept backing out so I got some new stainless steel studs and JBwelded it in there. So far it has stayed put and seems to be a permanent repair.
I was worried if the stud repeatedly worked loose and then tightened I might be looking at taking the heads of to get the threads machined.

I've not had too much luck with getting these out unbroken either but when I have soaked them in penetrating anti-seize and then heated really well they have come out.

I always wonder if butane blowlamp type torches get the heads hot enough (considering the temps the heads must see during the engine running) + the fact that the heads are aluminium and designed to dissipate heat effectively -Maybe a oxyacetylene torch on cool would do the job

[Bewildebeest]

for a pavorotti.

What ??

Took me a few seconds but I got there in the end.

[914bob]

Really appreciate these helpfull responses.

4 out of 8 of my studs came out - but the threads look reasonably together. I will make sure i really clean them up. I have seen those 'racer' nuts, Swapped, and will defo get some - much better clearance and access. Nige, your hex bar solution is ingenious - I like it!