The fans are 140mm
BITMAIN say this "Fans: Two 14038 fans mounted on both front and back ends."
That means 140mm wide by 38mm thick :-)
i doubt that these fans will be enuf for the cooling
i'll try to add some small heatsinks in the components
i think they already have additional heat sinks. the only heat sinks you might add are to the vrms. 40-41 degrees is running nice and cool.