I agree if SV group are said that New 50CC engine are the one they do modify from DL-50 v2 and make some improvment . but claims tha DL engine are made by them? I dont think it's true. I know the guy who made DL engine , his Chinese name is Dong Lin. that's why the engine call DL .like DA are from Desert Aircraft . as an friend of DL. we build the cylinder parts in the same factory (made 3mm cylinder too) . so only things I can think is SV group make copy from DL( see the cyclinder have no mark of DL. and all DL cylinder should have the DL-50 MARK on it) and try to confuse everyone who know the big name of DL but SV. it's cross of my main how ever. if this New SV engine are as good as it look, donts matter it's us DL brand or SV brand or any other brand , it's will be good for the people who like to buy because SV always have advantage about low price for sure , ha ha ")