I have two of these type of hoists. Keep in mind that ratings for
lifting humans are generally half of the rating for lifting dead
weight. This is just an extra safety factor. So 150kg should be worth
300kg as an engine hoist. Experience has shown that it's not a good
idea push it that far.

A Mini engine/gearbox is about 135kg. This should be well within the
capacity of such a lift. I wouldn't want to lift too much more since
these hoists seem more flexible than the usual multi-ton units
available here. The nice thing about them is that the legs are more
closely spaced and they fit under the car more easily. In fact one of
mine has adjustable spacing of the legs.

One thing you do not want to do with one of these is try to roll it
any significant distance with the engine suspended. This can be a bad
idea with the larger units as well but the small ones will start
bouncing since they are more flexible. I usually throw a couple of
boards across the legs and lower the engine to roll it around.

Cheers,

Kelley