Engine Swap: An Overview

Cost
Not only is a used engine the least-expensive option, but it generally will require less labor to replace. That's because you generally don't have to strip it all the way down to the bare short-block and head(s) when transferring parts, especially in lower-mileage examples. Vehicle downtime will be reduced because used engines are usually sold with attached and (normally) sound accessory components. That can come in very handy if your vehicle's existing components are worn or about to fail anyway.

Quality
Although it would be hard to argue against the absolute quality of a brand new, OEM replacement engine or a custom-built crate motor, it would be easier to argue in favor of the better cost/quality ratio of a low-mileage used engine. As mentioned earlier, if there is not a pattern failure problem with the engines for your vehicle model, the used engine should give reliable long-term service—providing that it is prepped correctly upon installation.


How about rebuilt or remanufactured engines? While their cost/quality ratio can at times be favorable when compared to the used engine, this is not always the case. Depending on the engine, it may suffer from poor core quality or availability. In addition, complexity in the rebuilding process can lead to a number of compromises that may adversely affect the long-term durability, or even the installation compatibility (fit) of the engine.

Availability
If the vehicle in question is a recently-introduced model, there may not be any rebuilt/remanufactured, or possibly even new engines readily available at any price! Here are a few tips on selecting a worthy used engine for your vehicle:


> Insist on getting an engine from exactly the same model of car as the one you own. Doing so can sometimes be the hardest part of the whole procedure. Although many manufacturers may use a certain engine design to power a number of different models, keep in mind that with different drivetrain layouts spanning more than a couple of model years, they probably won't all be good interchange candidates. Certain unscrupulous or uninformed suppliers of used parts may say that interchange compatibility exists when it actually doesn't-which may be especially true if you are seeking a low-volume option engine that they don't have in stock. Upon engine selection or delivery, go over it with the proverbial "fine-tooth comb" to check compatibility.