Hi Guys. I am a new member here and would appreciate some help. I am restoring a 1971 R75/5 and am in the process of installing the cylinder studs following a full strip down for blasting as everything was VERY dirty. The isuue I have is that with the case heated to spit boiling temperature the studs are so tight that the double nuts are slipping. I guess I must be doing it wrong so what is the correct procedure please?
Many thanks in advance from the UK.
Welcome Aboard !
I am not aware of any heating required to install the cyl studs.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
What did you blast with? Even with CO2 blasting the crud you are blasting off will get inside everywhere. If you media blasted the media, even soda, AND the crud will be inside every hole and passageway. In this case all the blanking plugs will need to be pulled and very passage and hole brushed and flushed.
I would investigate what is in those holes. You might try spinning a tap in with your fingers and see what comes up between the tap flutes.
I have to wholeheartedly agree with Arni.
ANY TYPE of media blast (glass bead, corn cob, walnut shell, steel shot, soda, etc, etc) will leave residue in the form of tiny to microscopic bits of media inside the engine. This doesn't sound bad until you realize that modern engine oils are all High Detergent. They are actually designed to pick up trash and take it to the oil filter. But most of these oil galleries are after the oil filter, but before the crankshaft and cam shaft. And it's not a one-time deal. The media gets embedded in the soft babbit of the main and rod bearings. So the overall effect is like holding sandpaper against all the mating surfaces where engine oil is delivered... for the remainder of its very short life.
To get this stuff out once it's introduced is nearly impossible. Hot water with detergent in an ultrasonic cleaner is about the best method. This is why good engine builders will use a chemical cleaner, not a media blast.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Many thanks for the replies. I think the problem has been correctly identified as blasting residue. Clearly the post blasting cleaning was not good enough so a new very thorough decontamination, including all the oil ways and threads, has been carried out and now the studs are installed correctly without the need for heat.
The reason I was using heat is because that was what was needed to remove the studs in the first place from what proved to be a badly damaged but previously blasted case which has now been junked. No doubt the removal difficulty was also caused by blasting residue.
Once again thank you for your assistance.
Glad to help. And hope you found it informative as well as useful.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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