Shroud question

[Pleil]

Hi all, I have been thinking about adding a fan shroud to my rig and had a question. I have read the diesel shrouds are steel instead of plastic. Is there a reason? Runs hotter? Can I go with plastic? Thanks

 

[Robert Kenney]

They don't run hotter.
Either material will be fine if you intend to build one. Easy with sheet metal and you should think about rimming the fan opening.