It's a Tian Zhong Technologies engine ... probably with a Lifan clutch cover plonked on it ... and it's probably only a 107 too ... LOL ... IF the cylinder studs are only 6 mm ( the head nuts are only 10.5 mm across the flats) ... it's definitely a 107 ... Longer stroked engines need 8 mm studs to avoid blown head gaskets ...
I bought a brand new full auto electric start 107 off A-1 Importer and its engine # is TZH152FMH ... It was delivered in a Tian Zhong Technologies box ... I won it on ebay one Monday night for $120 ...
The cam end plate on 'em has really thin fins ... Did you buy that engine new ? ... IF not someone could have changed the side cases and head ... or maybe some shady backyard assembler over in China is slapping their own engines together from parts sourced from here and there ... The last letter on the engine #'s designates the series of the engine ... ie mine is a "H" series ... later model engines were "I" series ... and then came the "J" series ... Theoretically ... the next series should be FMK's ...
Something's a bit sus with the "57" ... I'll bet it hasn't got a 57 mm bore ... especially since you can only bore to 54 mm with the 110/120 small valve head stud pattern ... The case bore is only 56 ~ 57 mm and the studs are really close to the edge ... Maybe some newby worker stuffed up the stamping of a batch of cases at the Lifan factory so they flogged the cases off cheap to Tian Zhong ? ...
I've seen tons of stuff that "appears" to be good go into the scrap bins at factories due to slight machining tolerance / production errors ...
From the flywheel side it looks extremely Loncin/Ducar like ...