Technical name / engine caps

[Dman2019]

Hi all,


I'm looking at removing the engine to do some work on it and to clean it up/spray it.


Instead of putting rags in the air intakes/exhausts outlets I was thinking of getting plastic caps for them.


Any ideas what they are called?  I have tried several searches/called them different things but cannot find them.


Anyone bought these before and can recommend a company to get them from?


Thanks


Darren