Thanks everyone for comments.
Erik_S, yes I know : I will fix them later, and the red material is better now. Not yet good, but better
It should be a bit grainy, as this engine cover is cast.
I know it's far from being completed. But I think I will post it anyways, so I will spend the last time I've for CG tonight to produce final renders and wires.
I still don't know which color I'll be using. Orange, yellow, red, blue, maybe apple green or turquoise : yes Palat, I said I loved your turquoise idea
