Could be a lot better. You have an inlet that provideds for a lot of inlet area but fails to direct any of it to the hottest portions of the cylinder. What makes that even worse is a lack of exit area. You're arrangement may be making things worse because it is trapping most all the cooling air at the cylinders, permitting it to collect heat without releasing any. You have to provide a place, with appropriate volume, to escape, taking heat with it. You're method of slowing the intake air is good, but without a means to exit it is likely getting pretty hot. Likely hotter than it would without any baffling at all.