If you remember back in April I experimented with a 3D PLA air filter for old car. This was run off from some spare filament I was using for the ships
as I was concerned about not having a filter on the car and original metal ones are super rare and very expensive. Some were sceptical if standard
(cheapo) PLA would last in a hot engine bay, the carb being directly above the exhaust. However after a lot of use over the last 7 months and the hot
summer, I can report that the filter has not suffered in any way. Nothing has melted, warped or cracked, indeed it just looks the same but a bit
dirtier (yes I sprayed it with red primer at the start as the grey stood out). It's performed great removing my concern when stuck behind a
dumper truck etc and has reduced the engine roar dramatically. I haven't cleaned the foam filter, there's so much of it in there, only oiled
it now and again.
So yeah PLA in an engine bay, seems to be fine (if your sensible)
I saw a vid the other day which claimed a 3d printed airbox on a small aircraft had collapsed, depriving the engine of air, and said aircraft crashed,
I shall try to find the vid. but from memory it was sold as carbon reinforced nylon, but actually just pla.
Well I did say if you are sensible. I had already measured the temp it got after a good hard run and it was perfectly within the limits of PLA.
There's actually a lot of ventilation and space in the engine bay.