i need help figuring out what this engine is. It was originally purchased by a friend, thinking it was an HPI 4.6. yet it has no stamping from hpi on it

It maybe a 4.6 ,but it also kind of looks like the 5,9 ....in which it does have a 36 stamped on the bottom ,I don't know if that
means the size or not ,but a 36 is a 5.9.

I have several 5.9 's I would have to look at them to give a definite answer!