The AC Ace roadster first hit the market in 1953 and featured a variety of different engines throughout its lifetime, with the most potent being a 2.6-litre straight-six engine sourced from Ford. It served as a fine handling machine that could almost be used in competition on the road, but in Texas, Carroll Shelby (1923-2012) decided it needed significantly more power. Instead of outright rejecting the idea and quickly moving on to another task, he chose to build the Cobra, which was a highly-modified version of the Ace equipped with a Ford Windsor V8 engine, starting with a displacement of 4.3 litres and later increasing to 4.7 litres. The Cobra emerged as an absolute beast in the racing world, especially when it entered the next era with a formidable 7.0 litre Ford FE V8 engine nestled under the bonnet.
Alpine A110
The original A110, which was not the version launched in 2017, featured Renault's tiny Clon-Fonte engine at first. Later on, engineers replaced it with the bigger Clon-Alu, the same engine that eventually powered the Renault 16. You wouldn't think the 16 would make a very good race car, but its engine indeed made the A110 a true winner in competitive racing. In the first World Rally Championship held in 1973, Alpine triumphed, winning six rounds and finishing the year with a total of 147 points, while Fiat ended up with just 84 points and Ford with 76 points.
Audi A4
Audi is no stranger to the segment, consistently dominating it with its impressive lineup. Nearly all the models in the range feature high-performance S variants, and in many cases, they showcase even more exciting RS variants, equipped with engines that are significantly more potent than their regular counterparts. A4 serves as a classic example of this trend. The RS 4 versions of the A4 have always boasted a remarkable engine—the best yet being the tearaway 4.2-litre V8, which is also fitted to the Audi R8, delivering more than 400bhp and staying well ahead of any other A4 on the market.
Audi Q7
Every Q7 is a monster of a thing, whatever drives it, but Audi truly took that concept to a new and surprising degree when it installed a powerful 5.9-litre diesel V12 in the big SUV. The impressive 493bhp powered the Quattro Q7 – which weighs 2,635kg – and had it finishing from a standing start to 62mph in just five and a half seconds. Fortunately, the engineers equipped it with brakes and suspension that were equal to the demanding task, but the exhilarating acceleration like that remains thrilling - or scary - in equal measures for many drivers. And it certainly didn't come cheap. Priced at just under 100,000 in the UK, the 6.0 V12 TDI - as it was called - made the vehicle around 40,000 more expensive than the next most costly Q7. And the best estimate suggests that only 21 can be found on UK roads today.
BMW M3
By the very nature of things, engineers have fitted all M3s with an engine that turns them into beasts of a different colour. This was especially true for the range that enthusiasts enjoyed between 2007 and 2013, as they equipped the cars with the 4.0-litre (and, for the GTS version, 4.4-litre) S65 V8 engine. Four times a winner, this exceptional engine delivered more than 400bhp right out of the box, meaning it was the first M3 to achieve that impressive output in standard form. It was not the only V8 to find its way into an M3, as a handful of earlier models were also so fitted, but it stood out as the only all-Porsche V8 in an M3.
Cadillac CT6
As a general rule, all variants of the CT6 were huge luxury saloons. However, the CT6-V wasn't just a big luxury saloon; it was a formidable unit as well, equipped with a 550bhp 4.2-litre V8 motor. The CT6 Platinum (shown here) was also available with a 500bhp engine. The two Blackwing cars went on sale for the 2019 model year only. GM discontinued the fleet of all-GM powered cars very soon thereafter, in part due to lackluster sales and in part because the Detroit-Hamtramck plant, where every version had been assembled, was being prepared to build electric vehicles. The Blackwing name has been revived for the most powerful versions of the CT4 and CT5, but neither utilizes the Blackwing engine.
Chevrolet Corvette
It's odd to think now that as the most-available sports car of all time, the first-generation Corvette didn't attract much popularity when it came out back in 1953 with its straight-six. Two years on, Chevy offered it with the new Small Block V8, initially in 4.3 litres (later extended by the extra 0.3 and then another 0.8 litres, to 4.6 and then 5.4 litres). It was as if this was the change the people had been waiting for. Corvette sales took off, and that model that could have been given up at an early stage still continued right up until 1962. Its latest descendent six decades on is a success to this day and still has the same engine.
FAQ's
1. What makes an engine swap worthwhile?
A new engine can drastically improve horsepower, torque, reliability, and fuel efficiency, breathing entirely new life into an aging or underpowered chassis.
2. Are engine-swapped cars street legal?
Legality depends on local emissions laws, noise regulations, and whether the replacement engine matches or exceeds the emissions standards of the original vehicle year.
3. What are the most popular cars to modify with a new engine?
Iconic platforms like the Mazda Miata, Nissan 240SX, Honda Civic, and older muscle cars like the Ford Mustang are frequent choices because of wide aftermarket support.
4. How much does a custom engine transformation cost?
Costs vary wildly from a few thousand dollars for a straightforward used swap to tens of thousands for high-end custom builds, upgraded wiring, and supporting modifications.
5. Does a new engine ruin the car's resale value?
While purists might pay less for non-matching numbers, enthusiast buyers often pay a premium for a professionally built, high-performance engine transformation.
