Seized up exhaust studs
 

I just came across this tip for freeing seized steel studs in an aluminium cylinder head. Rather than soaking them in WD-40 or whatever overnight try Tizer instead- yes I do mean the fizzy drink. This came from a Biggin Hill-based firm of aircraft engineers to a friend of mine who had by then broken off one of the studs on his aircraft engine, the other one came out no bother with this dodge.
John

Shell's special blend "Fire and Ice" car oil will free up just about anything, remove rust, and so a number on rings. I wouldn't use it as a sump oil, but it is amazing in penetration ability

Personally, i've always had good luck with "liquid wrench" from Gunk.
...WTF is Tizer???

Heat up the stud with an oxy acetylene torch until it's cherry red and then allow it to cool off .Don't heat the alloy .
The stud will have been loosened by the heating and cooling cycle and you will now be able to unscrew it .
Fizzy drinks may work if they can bust the crud seal between the steel stud and the alloy head .
But if they can do this , just think what they do to your guts !

Dodger

Mr Ron
Tizer is a UK fizzy drink, like coke- but totally unlike coke

Bill

Maybe just as corrosive though .

http://www.tizer.co.uk/index_colourz_home.html

and if you really must have it ;
http://www.britsuperstore.com/acatalog/Tizer.html

Dodger .

The explanation of how it works has just appeared in a letter by Graham Webster, Treasurer of the BMAA, in 'Popular Flying'. In fact the tip first appeared in the previous issue of the magazine, it was written in an article by a friend of mine and refered to the engine of another friend.

It says that most fizzy drinks contain Phosphoric Acid, H3PO4 (mmm, nice...) and is there as a flavouring to give the tartness. Rust jams nuts and studs because Iron Oxide (rust) takes up more space than the iron did before it got oxidised. The Phosphoric Acid reacts with the Iron Oxide to form Iron Phosphate and water. The Phosphoric Acid reacts more quickly with the Iron Oxide than it does with the un-rusted iron, but all traces of the acid i.e. the Tizer/Coke should be washed off after the de-rusting is completed. The result of the reaction is a deposit of Iron Phosphate on the nut/stud which actually inhibits further rusting.

With thanks to Graham Webster,

John