In car tuning culture, an engine swap is the process of removing a car's original engine and replacing it with another. This may be a like-for-like replacement or the installation of a non-factory specification engine. Typically, an engine swap is performed for performance using a more powerful engine, but may also be performed for ease of maintenance as older engines may have a shortage of spare parts.
Overview
An engine swap can either be to another engine intended to work in the car by the manufacturer, or one totally different, with the former being much simpler than the latter. Fitting an engine into a car that was never intended to accept that engine may be more laborious and costly, and may involve modifying the car to fit the engine, modifying the engine to fit the car, and building custom engine mounts and transmission bell housing adaptors to interface them, along with a custom-built driveshaft. Some small businesses build conversion kits for engine swaps, and many shops and companies perform engine swaps for customers.
Swapping the engine may have negative effects on a car's safety, performance, handling, and reliability. For example, the new engine may change the weight distribution and overall weight in a way that adversely affects vehicle dynamics. Existing brake, transmission, and suspension components may also be insufficient for the increased weight and power of the new engine, with either upgrades being required or premature wear and failure being likely. It may also be difficult to get the car's interior and exterior features, such as the headlights or gauge cluster, to work with the new engine.
Insurance companies may charge more or even refuse to insure a vehicle that has been fitted with an engine different from its initial configuration. It may also be harder to register an engine swapped vehicle or get it to pass government mandated safety inspections. For instance, in jurisdictions such as California, with its strict smog rules, it may not be possible to register a late-model vehicle with an engine swap.
Types of swaps
American engines
A common anecdote[citation needed] among tuners in the United States is that the easiest way to make a car faster is to drop in a more powerful engine. The LS swap, which involves swapping a General Motors LS-based small-block V8 engine into a car which either didn't originally come with it, or came with a different variant of it, is considered to be one of the most popular engine swaps in the United States,[1] being swapped into a wide variety of cars from many manufacturers. Prior to the introduction of the LS engine, it was also popular to swap both small block and big block Chevrolet V8 engines into a number of cars.[2]
Ford V8s such as the 302 and Coyote are also popular for engine swaps.[3] A 302 fitted with aluminium heads, intake, and water pump only adds about 40 lb (18 kg) to the front of an MG MGB and is substantially more powerful and lighter-weight than the iron-block six-cylinder found in an MG MGC or Triumph TR6. Aluminium 302 performance blocks are available that weigh 60 lb (27 kg) less than the common iron versions and can be found in displacements of 331 and 347 cu in (5.4 and 5.7 L), but they are significantly more expensive.
British sports cars (such as MGs, Triumphs, and Sunbeam Alpines) from the late 1960s and early 1970s were popular choices[citation needed] to engine swap with more powerful or durable engines. The original manufacturers did this when the vehicles were current with the MGB GT V8 and the Sunbeam Tiger. From an aftermarket perspective, the all-aluminum 215 cu in (3.5 L) Buick and Oldsmobile V8 engines are a traditional choice for these cars. Derivatives of that classic General Motors engine, the 3.5L, 3.9L, and 4.2L Rover V8s are also frequently used. (The original Buick/Oldsmobile, the Rover, and the related Morgan-licensed V8, are simple bolt-ins.[4])
Chrysler sold many turbocharged models in the 1980s, and the engines they use share much in common with their mass-produced naturally aspirated counterparts. It is quite common[citation needed] to swap a Dodge Daytona engine into a Dodge Aries. The Mopar Performance division even offered a kit to upgrade the Daytona to rear-wheel drive with a Mopar V8.
Although the more recent 60-degree Ford and GM V6 engines—notably GM's 3.4L L32—are more compact than Buick/Oldsmobile/Rover and Ford V8s, they usually do not equal the power-to-weight ratio of the popular 90-degree V8s frequently swapped into smaller cars. These V6s can, however, be very cost-effective and easier to fit into a variety of cars.
With the rise of electric vehicles, there has been a growth in the popularity of EV swaps, which take a vehicle originally powered by an internal combustion engine, and replace its engine and running gear with one or more electric motors and an accompanying battery pack. The electric drivetrain is often taken from a Tesla or another widely available electric vehicle. Multiple companies have been founded which offer EV conversions for classic cars.[5]
Two of the most popularly swapped Japanese engines are the Toyota 1JZ and 2JZ inline sixes.[7] The Toyota UZ V8 is also a relatively common swap.
The Nissan SR20DET inline-four, Nissan RB series of inline-sixes, and Mazda 13B rotary engine, are also commonly swapped engines into a variety of platforms.
Engine swaps are also somewhat common within the Volkswagen tuning scene, with Type 2 (Bus), Type 3, and Type 4 engines often being swapped into the Type 1 (Beetle). Later water-cooled engines, such as the GTI 16-valve four, VR6, or 1.8T are commonly swapped into the Mark 2 Golf GTI, Jetta, and Corrado, or less commonly into a Mark 1 Golf, resulting in an excellent power-to-weight ratio even with minimally modified powerplants. Porsche engines are also very popular, with one of the most popular source engines being the 1.6L flat-four from a Porsche 356.
Diesel engines
Swapping to a diesel engine for improved fuel economy is a long established practice; with modern high-efficiency diesel engines, this does not necessarily mean a reduction in performance associated with older diesel swaps. For off-road vehicles in particular, the high low-end torque of turbo-diesels makes these conversions particularly effective. However, older non-electronic-injection diesel engines are well-known for their reliability, especially in wet conditions.
Motorsports
In Super GT's GT500 class prior to the introduction of the Class 1 regulations, most cars were provided with specially modified racing engines from manufacturers, as the rules allowed for any engine to be swapped into a car as long as it is from the same manufacturer. Notable examples include Toyota using highly tuned Celica-sourced 4-cylinder engines in their Supra GT500 race cars.
List of commonly swapped engines
Note: These are the most common examples and are not an exhaustive list, just a representative cross section.
Hot rods, kit cars, pickup trucks, 1950s-1970s GM muscle cars
7.7 or 8.2 L (472 or 500 cu in)
One of the largest displacement car engines ever mass-produced, with the biggest ones being 500 cubic inches (8.2 litres), and capable of accordingly high torque figures. Easy to acquire from scrapyards.
The SBC ("Small Block Chevy") was designed for a wide range of displacements in a compact package, being lighter and more compact than previous V8s of similar displacement due to improvements in metal casting techniques. It has been available in sizes ranging from 265 to 400 cu in (4.3 to 6.6 L). Mass production has made this engine quite abundant and affordable, with the most common displacement being 350 cu in (5.7 L).
There are a wide variety of various adapter plates for the B series due to its wide use in agricultural and road vehicles. Normally used as a swap for its reliability, low-end torque, and fuel economy.
The 4BT 4-cylinder is desirable as a diesel swap[citation needed] due to its compact size and lower weight compared to its 6-cylinder counterpart. Using a stock GM transmission adaptor plate for a 4BT will give the engine a slant, while Ford and Dodge adapter plates will not.
Uses an iron block and an alloy head. Has gained world wide recognition and support, competing with the Toyota JZ series and Nissan RB series due to their tunability.
If installed in a Saab 96, it makes the car nose-heavy and requires relocation of the radiator to the side or rear. There is also a Cosworth-designed 24-valve version.
Uses a large iron block with an alloy reverse flow head (with integrated manifolds) and a pushrod valvetrain. These engines were common given the ease of swapping, with mounts, sumps, transmissions etc. being shared with the stock engine. The CF6 has been succeeded by the SOHC Intech and the DOHC Barra engines.
Hot rods, kit cars, Ford Mustang and other pony cars
4.6–5.8 L (281–354 cu in)
Sharing many of the same components with the previous Windsor family, it replaces the cam-in-block pushrod valvetrain with an overhead cam for better high-RPM breathing, making this engine wider and taller than previous Ford variants (being about the same width as the Ford FE V8 engine). The 4.6L V8 is the most common version.
The 351W has a higher deck height (and thus a longer potential stroke) than the 302W, but both can swap heads. The fully assembled 351W is taller and wider than the 302W, leading to the 302W being more popular for swaps into smaller cars.
Early 1990s 302Ws have a high nickel content in the cast iron and are considered desirable.
Jeeps, Chevrolet S10, Pontiac Grand Am, Pontiac Fiero, hot rods, kit cars
3.8 L (232 cu in)
Conversions are popular[citation needed] due to the engine's prevalence in GM midsize cars and minivans from the late 1980s through mid-2000s. Even though it is a 90° V6, the engine shares the GM 60° V6bell housing bolt pattern, so swaps between FWD and RWD transaxles and transmissions are straightforward. Can be adapted to more traditional front-engine/rear-wheel-drive setups and is a cousin of the Rover V8.
Hot rods, kit cars, Pontiac Fiero, various British sports cars, Chevrolet S10
2.5–3.4 L (153–207 cu in)
Can be fitted in both front- & rear-wheel drive applications, sharing its bell housing pattern with the Northstar and Buick V6. That said, transverse & inline engines use different blocks. A notable example is the cast-iron 3.4 L (207 cu in) L32, designed for longitudinal rear-drive applications. The high-airflow aluminum heads and intake from the 3400 as used in the Pontiac Grand Am GT are a direct bolt-on.
Compact and light, these engines typically use a cast iron block with aluminum heads (although some variants have an all-aluminum construction). As with the SBC, mass production has aided in availability. There are many minor improvements over the previous SBC.
Although aluminum blocks remain expensive, the two most common versions for swaps are the 5.3L LM7 and the 6.0L LQ4 and LY6, all of which can be found in salvaged trucks and SUVs.
Not suitable for longitudinal RWD layouts as it turns counter-clockwise (as with the Chevrolet Turbo-Air 6), though it can be used in a mid-engine layout.
Of particular note is the B18C from the Integra Type-R, which easily bolts up to the lightweight Civic hatchback.
1990–97 Accord engine swaps are straightforward drop-ins with minor modifications required for the wire harness, whereas the 1998–2002 Accords require swapping the driver-side mounts to fit. As this engine is also used in Formula 3 cars, it is able to be fitted into a RWD car.
Popular in certain circles because it produces more torque than a four-cylinder. Can be used in both front- and rear-wheel drive layouts; the latter can be done with a GM TH-400 automatic transmission or the transmission from a Mazda MX-5 or Honda S2000.
The most common displacement is 3.2L, though it can also be found in 3.5L and 3.7L variants.
The K-Series was mass-produced for a wide variety of common Honda vehicles, making it relatively affordable. It can be turbocharged and retrofitted to many smaller and lighter Honda cars, such as the Civic. K engines can be used in both front- and rear-wheel drive layouts as they rotate clockwise, and adapter plates are available to bolt one up to the transmission from a Mazda MX-5.
Can be used in both front- and rear-wheel drive applications, with the transmissions being used in many other applications. Adapter plates are available to fit other engines in front of it.
Austin-Healey Sprite, light aircraft, Lotus 7-style kit cars, Mazda MX-5, MG Midget, Suzuki Samurai, VW Type 1, VW Type 3
0.4–2.6 L (24–159 cu in)
Very light and compact, suiting a wide variety of small RWD cars. Also popular for home-built aircraft due to their light weight and high power potential.
Fitted to many Mitsubishi models, including the Eagle Talon 1G and 2G with the DOHC turbo model. Installation into 4G and early 5G Mitsubishi Lancer variants is relatively straightforward and can use mostly standard Mitsubishi parts,[8] as the Lancer Evolution models used essentially the same engine. Later 5G Lancer models have the 2.0L 4B11T engine and simplified transmission that result in the intake and exhaust manifolds being on opposite sides compared to the 4G63.
Various British sports cars, Hot rods, kit cars, light aircraft
3.5–5.0 L (214–305 cu in)
This small aluminum-block V8 weighs less than some iron-block four-cylinder engines.
Typically mated to a T5 gearbox as used in Cosworth-powered rear-wheel drive Fords – this requires the correct bellhousing (usually available off the shelf), similar to TVRs. British Leyland's LT77 (as used in the Sherpa van and Rover SD1) may also be used, but wear can be a problem in units having been driven well over 70,000 miles. Later LDV Pilot vans used a two-wheel-drive version of the stronger Land Rover R380 transmission that was developed from the LT77.
This liquid-cooled flat-four engine has a factory turbocharged version that is quite desirable for certain applications. Adaptors are available off the shelf for a wide variety of swaps, provided the automatic transmission models are not used.
Older Hiluxes were equipped with 4-cylinder engines ranging from 90 hp (67 kW) and 122 ft-lbs torque (1979-80 carbureted versions) to 135 hp (101 kW) and 173 ft-lbs torque (rare 1986-87 turbocharged versions). These older engines have relatively low compression ratios ranging from 7.5:1 to 9:1; when used in a daily-driven rock crawler, an average fuel economy of 12–16 miles per gallon is expected.
The much improved 3RZ-FE engine features a 9.5:1 compression ratio and uses newer technology such as a hot wire mass airflow sensor, knock sensor, and a narrow angle DOHC cylinder head. The result is a more efficient and more powerful engine, achieving 17–21 miles per gallon in rock crawler applications.[9] Additionally, the 3RZ-FE uses the same W-series family of transmissions as the older fuel-injected Hilux, so an older W56 transmission may be used with the new 3RZ-FE by using the W59 bellhousing. The 3RZ-FE flywheel and clutch components are also fully compatible, making it a great replacement engine for old Hiluxes.
The 4A engine was offered in different configurations ranging from 90 to 170 hp (67 to 127 kW). The high-performance variants included either a five-valve-per-cylinder configuration or a Roots supercharger.
Conversions are popular[citation needed] due to a vast aftermarket and many compatible parts between engine versions. Some conversions are very easy; for instance, the supercharged 4A-GZE engine and electronic fuel injection system are a direct plug-and-play conversion into a non-supercharged AW11 MR2; even the supercharged model's wiring harness plugs directly into the non-supercharged model's chassis harness. The non-SC flywheel, clutch, C56-type transaxle, and axles can all be directly fitted to the SC engine with no modifications, making conversions less of a hassle.[citation needed] FWD variants are also able to be converted to RWD.
Also one of the common swaps for the Morris Minor, using a Toyota T50 5-speed manual gearbox.
These are Triumph engines in Norton Featherbed frames. The idea was to combine the best engine with the best frame to create the best of both worlds—namely, a high power-to-weight ratio.
Aftermarket kits make this a straightforward conversion, but it may also be possible to use the equivalent petrol engine with them too. A kit could be adapted to a small hot rod or kit car with the petrol engine.
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Moreover, in the mid-1980s, hot rodders discovered the 215 could be stretched to as much as 5 L (305 cu in), using the Buick 300 crankshaft, new cylinder sleeves, and an assortment of non-Buick parts. It could also be fitted with high-compression cylinder heads from the Morgan+8. Using the 5 liter Rover block and crankshaft, a maximum displacement of 5,208 cc (317.8 cu in) is possible. Davis, Marlan. "Affordable Aluminum V8's [sic]", in Hot Rod Magazine, March 1985, pp.84-9 & 121.
