Toyota has updated the Auris’s 1.4-liter VVT-i engine with a new, smaller, and more efficient Dual VVT – I powertrain. This means it produces power just as well as previously while using less fuel and weighing less than its four-wheeled brethren.
In addition, the Toyota 1NR is 36% lighter as a result of thinner pistons. Among other changes made by Toyota engineers, this redesigned motor design has had an impact on the engine’s development and overall success.
And today, we will talk about a similar engine to the 1NR-FE, the 4NR-FE engine. It resembles the same features and characteristics of the 1NR-FE with some detailed work changes.
What are Toyota 4NR-FE Engines?
The enthusiasts in China will be happy to know that there is an analog of 1NR-FE for their market. It’s called the 4NR-FE. This engine produces a maximum output power of 98 HP and has peak torque at 123 lbf·ft, which makes it perfect if you want a harmonious combination between performance, economy, fewer carbon emissions, pricing, versatility, and durability with minimal maintenance requirements.
With the development of the new small-displacement series, Daihatsu’s contribution to Toyota was given priority, and the development of the new engine class was given priority by Daihatsu, but NR engines are best known for being a Toyota engine.
However, NR engines are best recognized as model engines that have been used in many different models over time because they’re powerful and reliable with low emissions, which makes them perfect for any vehicle type.
The engine blocks of the NR series are made of aluminum, and the cylinder heads are DOHC. It also has four valves per cylinder and uses multi-point or direct fuel injection. Dual VVT-i is standard on the 1NR, 2NR, 3NR, 4NR, 5NR, 6NR, and 7NR engines, while VVT-i is standard on the 8NR engine, allowing it to operate in both the Otto and modified-Atkinson cycles to improve thermal efficiency.
Engine Specifications and Design:
- Production Run: 2012 – Present
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Aluminum
- Configuration: Inline 4
- Bore: 72.5 mm
- Stroke: 80.5 mm
- Valvetrain: DOHC four valves per cylinder
- Displacement: 1.3 L (1329 cc)
- Compression Ratio: 11.5
- Weight: 196 lbs. (dry)
- Maximum HP: 98 HP at 6,000 RPM
- Maximum Torque: 123 lb-ft at 4,200 RPM
Engine Design:
The primary goal of the 4NR-FE engine is to be shipped in Chinese markets as the same engine of the 1NR-FEs. They are of the same build and differ from little to none. Hence, we can say that this engine is a shadow and full resemblance of the 1NR-FE, which we can also see in other markets.
The reason why Toyota released Chinese versions of these engines is due to the production as well as shipping concerns. Most of these Asian versions are manufactured in Asia, so the plants in the Western regions do not need to sacrifice a huge chunk of money for them to ship in Asia.
1. Cylinder Block
The cylinder block is intended for lightweight engines with high compression ratios. The aluminum “open deck” with thin cast-iron liners functions as a single sturdy component, delivering strength and power that will endure until the engine is rebuilt.
The beauty of these cylinder heads is that they are so compact. Because the wall thickness between each one ranges from 5mm to 8 mm, you won’t have any trouble with reboring your engine should anything go wrong. All it takes are some simple tools and skills.
The crankshaft of the engine has been shifted by 8 mm, which reduces the force imposed on cylinder walls and prevents wear. The four balancing weights have shorter journals to improve balance as well; this improves acceleration response time because there’s less weight shifting back and forth between one side.
An asymmetrical bore pattern makes it easier for oil to flow through without creating excess friction during the combustion cycle. The high-rise spacer is a fantastic invention that allows for more intensive coolant circulation at the top of a cylinder, which enhances heat dissipation and helps to equal out thermal load.
The camshafts are housed in a separate housing placed on the cylinder head, which simplifies the design and manufacturing process.
The valvetrain mechanism includes hydraulic lash adjusters, mainly for a smoother operation, as well as roller rockers. Old-style adjustable tappets are used in selling in Asian markets since the region prefers those types of parts over the more modern style technology.
2. Improvements
Toyota engineers have taken a new approach to engine design by employing advanced engineering techniques. They simplified the intake channel, used computer simulation for smoother airflow and better performance, rounded out all curves in order to produce an even cleaner look with less turbulence along its surfaces as well.
One of the most essential components of the 4NR-FE engine is the piston design. These pistons are the same pistons loaded in the 1NR-FE. So there’s no denying that these are good.
The thing is that they have a smaller contact area and utilize carbon ceramide, a complex material used in Formula One engineering, to reduce friction. They are more compact and lighter than the preceding 1.3 L model. The engine incorporates cooled exhaust gas recirculation to reduce pumping losses and NOx emissions.
Further, these pistons are composed of aluminum alloy and have a cut skirt as well as a little T-shaped protrusion. The top compression ring groove is anodized, while the upper compression ring edge and oil scraper are PVD coated for anti-wear.
The piston pins are press-fitted into the connecting rod and are not totally floating, which is a big drawback. Please keep in mind that Toyota officially prohibits the reuse of pistons, connecting rods, and piston pins from disassembled 1NR and 2NR engines.
Applications of 4NR-FE Engine:
- Third-Generation Toyota Vios (NCP150R) China Only
Problems Surrounding 4NR-FE Engines:
The Toyota 4NR-FE engine has been a legend for its dependability and efficiency. However, like any other machine, it comes with flaws that need to be addressed in order not to have troubles arise from them later on down the road. Let’s take a look at these common issues, shall we?
These are just some examples of what can go wrong when your four-cylinder motor. There aren’t necessarily more problems than usual, but they’re still worth mentioning as many people don’t know about these potential pitfalls yet or may believe their vehicle doesn’t have any issues.
Some of these include:
1. Excessive Oil Consumption
The most well-known and widespread issue with the 4NR-FE as well as its older brother 1NR-FE engine is high oil consumption, which frequently emerges at mileages much below 60,000 miles.
Toyota’s standard explanation is that the piston rings became jammed. The requirement to replace pistons and connecting rods concurrently does not allow for a low-cost engine renewal, although cylinder block reboring is not required.
Oil consumption is a problem that was recognized in TSB EG-0095T-1112. Production changes were implemented in early 2013, which included modified rings and pistons with connecting rods for those who had oily valves or nozzles on their machinery; they also replaced valve coverings when necessary to prevent any further problems from occurring due to this recurring issue.
2. Clattering noise from the Timing Chain area
You’ve just noticed a noise coming from your engine – it sounds like something is about to fall off. However, some say that the engine’s ticking or clattering noise is a feature and should be addressed as soon as possible. You have two options: ignore it, which could lead to more serious problems, or replace the timing chain with an updated design tensioner arm that will stop this from happening in future instances where it occurs again.
You can do it yourself by following manufacturer instructions according to model year on their website along with also hiring professional help if possible due to time and money constraints. Don’t worry, because this can be fixed with cheap and easy solutions.
3. Excessive Soot Deposits
Combustion during engine start often results in reduced power and higher fuel consumption. This can be attributed to the buildup of soot on various parts, especially those which are located near valves or valve seats – leading towards an extended period where you have lights coming on but no compression occurring.
TSB EG-00037T-TME recognizes this defect as another example where excess deposits may cause some reduction or losses within your drivetrain’s performance capabilities; however, we still recommend maintaining regular maintenance appointments just like always because nothing should go overlooked.
The following excerpt describes an issue with some automobiles in which it has been found that they take longer than usual due not just to the greater time required for ignition but also to build up within particular components such as pistons being covered with residue.
Summary
The Toyota 4NR-FE engine is an excellent and efficient power plant. It may be smaller than some other engines out there, but this makes it more lightweight as well. Additionally, all of our tests show that despite being fuel inefficient at times, due to recurring issues, you’ll want to stay with this engine with its VVTi drivetrain).
However, you can still rely on getting great gas mileage with no worries whatsoever – because who doesn’t love a good reliable vehicle?
This is the best bargain out there for anyone who wants an economical car with performance and reliability. It doesn’t have major issues, but it does require proper maintenance to stay in tip-top shape.