* The vehicle: Some vehicles are designed with engine swaps in mind and are easier to work on than others. Older cars are often simpler than modern ones with complex electronics.
* The engines: Swapping a similar engine into the same model car will be significantly faster than swapping in an engine from a different make, model, or even year. The more differences, the more adaptation and fabrication might be needed.
* The mechanic's skill and experience: An experienced mechanic can complete the job much faster than a novice.
* Availability of tools and parts: Having the right tools and parts readily available will speed up the process. Waiting for parts adds significant time.
* Complexity of the swap: A simple swap of a similar engine might take a weekend for a skilled mechanic, while a complex swap requiring custom fabrication and wiring could take weeks or even months.
A *very* rough estimate for a relatively straightforward swap of a similar engine in a reasonably accessible car by an experienced mechanic might be 20-40 hours. However, it's entirely possible for a swap to take far longer or, in rare cases, even less time. It's best to consult with a mechanic experienced in performing the specific swap you're planning for a more accurate estimate.
