Engine hoists are designed to be used for lifting engines and other large components during removal and/or fitting to a vehicle. They are generally provided with adjustable legs and arms and the position of these determines the safe load carrying capacity of the hoist. In addition the hoists are normally used with chains and/or straps which are also load rated. It is important that the equipment together with the chains and/or straps are not used to lift engines or components outside of these limitations as accidents can occur as a result.
Source: CDX Global & Wikipedia - en.wikipedia.org