Engine swapping – few topics divide the motoring world more. Some say it’s the riskiest, daftest thing you can do, while others see it as the perfect way to get more from your car.
We’re not here to say whether you should consider swapping your car’s engine or not. What we are here to do, though, is to give a practical introduction to what engine swapping is, and why it could make a great project for those who enjoy working on cars.
- What is Engine Swapping?
- Why Would You Consider Swapping an Engine?
- How Feasible is Swapping the Engine on Your Car?
- Engine Swap Checklist: What You Need to Consider When Swapping an Engine
Engine swapping is when you replace a car’s original engine with another, mainly for performance reasons or to get an older car back on the road when its engine has died. As you can expect, it’s one of the trickiest and most time-intensive jobs around, but it can be rewarding for those who like to tinker under the bonnet.
There are two categories that an engine swap can fall into, one being a like-for-like exchange where the replacement engine is built to fit in a certain car, and a non-factory specific swap which needs modifications to get the new engine to fit and function.
Of course, a like-for-like swap is a much simpler task than fitting a non-factory specific unit, with minimal modification required to get the engine to seat correctly. That said, any engine swap has its risks, and it’s a job that shouldn’t be attempted without the right equipment, tools and knowhow.
Here are the most common reasons that some petrolheads choose to do an engine swap:
- Improved performance and efficiency – the majority of engine swaps are carried out with enhanced performance in mind; it’s considered the pinnacle of tuning up a car to get the most output from it possible. A bigger capacity engine brings more power and torque, which translates to much higher performance for small, light cars that weren’t originally designed for use with a certain type of engine.
- Revive a classic – imagine you’ve bought a classic car and you want to bring it back to life, you’d do anything to keep it going, right? That’s where an engine swap comes in. By replacing the original with a newer, more modern engine, you can enjoy the thrill of driving an older car without fear that it’s going to conk out on you. Of course, it might be that you can get by with replacement parts, but if there’s a shortage or this gets too expensive, a full engine swap can be the next best option.
- Fun – whether you’re a trained mechanic or a driveway enthusiast, carrying out an engine swap is the ultimate challenge for those who enjoy fixing and maintaining cars. If you’ve ticked off every other job under the bonnet, a full engine swap could be your next big project.
An engine swap may sound like a good solution, but it’s important to keep in mind the size of the task and just how challenging getting the right alternative engine solution can be. Because in truth, swapping an engine is an enormous challenge, requiring a huge amount of time, planning and skill to get right.
Think about it: replacing a car engine is like performing a brain transplant, with every other function of the car relying on you getting the exchange bang on. From the fuel to the air intake, the gears to the dashboard warning lights; every element needs to sync up and work properly for the swap to be a success – a mammoth task for even the savviest of driveway DIYers.
Sure, there’ll be a lot of trial and error, and plenty of failures, but that’s all part of the fun and the obsession – the need to iron out the kinks and make something work.
What’s more, there’s plenty of help out there. Forums, Facebook groups and dedicated how-to guides written by those who have performed a successful engine swap can help steer your course to success, while vendors can help you find the right parts. Check out online sellers like Retroford.
If you’re thinking of swapping an engine, there’s plenty to consider before reaching for the toolbox. Here, we take you through a checklist of the need-to-knows of engine swapping, so you can weigh up whether it’s the right option for you.
Start with the Right Car
In principle, you could put any engine in any car (surely this isn’t true…a mini for example with a range rover engine – surely the space isn’t big enough) – provided you had some serious skill with a welder and lots of time on your hands. But that’s not really the point of engine swapping; it’s more to do with having the right car and knowing that it could benefit from a newer, more powerful engine.
Say you have an old Mazda MX-5, for example, and wanted to give it more juice. An engine replacement would work great, because the car’s low weight and sport-style brakes and suspension would mean that even a slightly bigger engine would greatly improve its performance.
This isn’t the case with every car. You need some base-line performance to make the upgrade worth it. An MX-5 is great because it already has the elements of a performance-tuned car; something a car like a Nissan Micra just doesn’t.
Choose the Right Engine
Next, you need to think carefully about the engine you want to stick under the bonnet. There’s no point going overboard here; too much power, and the brakes, suspension and fuel system won’t be able to cope.
The best way to find the right engine is to do some research (do we have any other blogs on this we could link to also). As mentioned, there are lots of helpful resources online, including loads of manufacturer-specific forums. Even when you think you’ve settled on the appropriate engine, check, check and check again before you make any big purchases or decisions – even if it means paying for the expertise of a professional.
Mounting and Fabrication
If you thought finding an engine was tricky, wait until you get to mounting it. This is one of the most challenging aspects of engine swapping, but it will be easier if you get the right engine to start with.
As you might expect, a like-for-like engine swap will be much simpler than going for a non-factory specific option. That’s because the mountings will be similar, if not the same, as the car’s original engine.
For non-factory options, lots of modification and fabrication will be needed to seat the engine and connect it to the car’s other components, like the axle and drivetrain. Lots can go wrong here, so we’d only recommend it for the most skilled of home DIYers.
Drivetrain and Gear Linkage
When and if you get the engine mounted, you’ll then need to start the complicated process of connecting the drivetrain and gears. This is when precision is absolutely key, as any mistakes made here could have a huge knock-on effect for the whole project.
For most engine swaps, custom shafts will need to be fabricated – unless you’ve purchased the engine from a specialist, in which case they should be supplied. These help the new engine connect with the existing front- or rear-wheel drive system.
Fuel and Cooling Systems
If you did your research when finding an engine, the unit you went for should be compatible with your car’s existing cooling system and fuel assembly. These are two of the biggest areas to research before you settle on an engine, because ideally, you’ll want to retain original parts like the radiator and fuel tank to save money and avoid the even bigger headache of replacing other major parts.
As with the drivetrain and gear linkage, custom hoses and fuel lines may be needed to connect the new engine to the original systems. Normally these can be bought alongside replacement engines; just ask the dealer what other parts and components will be needed for the engine to work in your car.
We hope this introduction to engine swapping has been helpful, and that it makes your decision whether to take on the job or not a little simpler. If you’d like to discuss the pros and cons of engine swapping with fellow car enthusiasts, join the Redex Club Facebook group.
At Redex, our engine additives and fuel system cleaners are developed to help you enjoy a better drive – whether you have an original or replacement engine. For more information about our innovative fuel and engine fluids, visit the homepage today.