I strongly suspect it is an Excelsior of the early 30's. Precisely which one I couldn't say as they made a variety of bikes fitted with a twin port JAP, Burman hand change box, twin down tube frame, etc, etc. Probably the frame number would confirm this as from 1931 Excelsior used an alphanumeral combination that identified the year and model.
Completely as an aside and I'm not having a go at our friend who wants to find out what he has, I'm always surprised how many people never seem to think the frame and engine numbers are relevant and don't include them with their request. Its no big deal, I'm just fascinated at how many people don't think they are important.
Anyway, Mateus, tell us the frame and engine numbers and we can help you.
Cheers,