It’s rare that I’m not surprised at the high quality of my prints (P1S, P2S). In this particular case it came out pretty crappy. I purposely used a BBL silk to get rid of it. If I liked the print I would reprint it with something more appropriate for an engine block. On this particular print, the quality just aint there. See where the two halves come together? It appears as though I dialed in a chamfer or fillet at the mating surfaces, but I didn’t. Is this just the nature of silk filaments. I almost never use them.
So far, I’ve had excellent results printing with Silk filament, but there’s one big drawback: Don’t use the default settings in Bambu Studio, but instead follow the recommendations on the Bambu website. Significantly reduce the speed and adjust the temperature.
Which settings did you use? Did you use the default settings for silk in Bambu Studio, or the optimised settings described in the wiki?
In general, I would consider cutting your engine block differently. Not so that the cut is right at the front and obvious, though. There are certainly better options, and this has nothing to do with the filament. 
I used the BBL settings for BBL silk.
I’ll read the wiki. Thanks
As far as I am aware, most PLA Silk is made by adding esters to PLA. Esters the things that make TPU squishy. As a result it can have some weird dimensional accuracy problems.
That makes sense. All the more reason for me to use it up on prototypes. I’m sure it’s great for some projects, but not the stuff I’m into. Thanks