BMW’s portfolio is loaded with great engines. Throughout the years, BMW pioneered the majority of engine technologies we have today. Consider the BMW’s 8-cylinder units that are a cultural icon, with their tradition revolving around powerhouse engines, and we simply cannot deny their curiosity and cleverness for the things they made for the automotive industry.
Engine Specifications and Design
- Production Run: 2008 – Present
- Cylinder Head Material: Aluminum-Silicon (Alusil)
- Cylinder Block Material: Aluminum-Silicon (Alusil)
- Configuration: V8
- Bore: 89mm
- Stroke: 88.3mm
- Valvetrain: DOHC with VVT Dual VANOS
- Displacement: 4.4 L
- Compression Ratio: 10:1
- Weight: 503 lbs.
- Max HP: 402hp
- Max Torque : 443 lb-ft
BMW’s core N63 engine is a belt-driven twin-turbocharged, 4.4 Liter V8 petrol engine which was produced from 2005 up to present and one of the first cars to suit N63 is BMW 750Li along with BMW X6 M and in M5 models starting in 2011. And would also serve the 5, 6, 7, 8-series, and X7 models in the BMW portfolio.
BMW N63 was launched as the direct successor to the prior B62 V engines, the face of a V8 tradition and an automotive breakthrough. With its groundbreaking design, they are the world’s first to market a “hot-vee” configuration – turbochargers located inside the “V”; and sophisticated technology working in collaboration with twin turbochargers and direct injection.
The factory-rated output of BMW N63 was 402hp at 6400 RPM with 443 lb-ft of torque available for the 1750 RPM to 4000 RPM range. Its components, such as the cylinder block and heads, are made from Aluminum-Silicon alloy or Alusil. BMW also equipped this engine with their patented Double VANOS system (Variable Valve Timing for BMW) since its production, even though some variants of early N63s do not feature the VALVETRONIC Variable Valve lift system.
The concept behind the N63 engine is complicated for some but let us break it down a little bit.
This layout that BMW spearheaded has numerous advantages, and one of those is the width reduction of the engine. The primary concern is to keep the exhaust manifold close – almost adjacent – to the turbo. In comparison to the traditional configuration, the intake manifold Is inside the “V,” and the exhaust manifold is outside the angle, which means that the engine’s turbos were placed in the “valley” of the engine, hence “hot-vee,” to keep them close to the exhaust manifold and reduce some lag for turbos. With the exhaust manifold and turbocharger units located between the cylinder, that space significantly reduces the distance between exhaust valves and turbochargers, making the turbocharger work more effectively and faster due to the shorter route. This also expedites the acceleration response as well as reduces the turbo lag in the engine. And for some reason, BMW omitted blow-off valves in N63s, which are replaced by diverter valves, maybe for auditory reasons.
Moving on, N63’s inter-cooling system is interesting but complex at the same time. Contrary to the standard style of air-to-air heat exchangers, BMW used air-to-water intercoolers for the first time, which is meant to gain some space to abbreviate the intercooler piping. However, due to high heat generation, air-to-water intercoolers need a separate coolant pump and reservoir with its own radiator installed in front of the engine, which further improved the throttle response of N63 engines.
Technical Upgrades of N63s
Since its release in 2008, BMW’s initial N63 engine has been in the automotive industry for more than two decades now; and that seems it requires some upgrades in its performance and technicalities. The initial N63, or N63A, was internally referred to as N63B44O0. IN63A is the core release of the N63 family. It bears the standard BMW technology such as Alusil Block and Heads, DOHC Double VANOS, belt-driven accessories, drive-by-wire throttle, direct-injection, turbochargers, and air-to-water intercoolers.
Five years after, in 2013, BMW updated its initial released to produce more power to level the competition throughout the field. This engine was also called N63TU; TU means Technical Update. One major mechanical change was the switch from drive-by-wire throttle to an intake valve-operated Valvetronic throttle system. Now, the primary control of the throttle is made by the opening of intake valves, and with that, it requires a different cylinder head and VANOS system. This engine produces 444hp with 480 lb-ft torque available.
Cooling systems were also changed, moving it from behind the headlight to the firewall, and a second Engine Control Unit was added to split the management of the cylinder bank.
After three years since its last update, N63s were again revised; this time, it is N63TU2 or N63R. The changes are minor and focus mainly on weight reduction, improved cooling system, and earlier peak torque availability.
Along with that, twin-scroll turbochargers were added to non-M cars with N63 engines. The relocation of the engine coolant from the passenger wheel well to the underside of the turbo reduces oil consumption; the pistons were redesigned with more oil drain reliefs which allow more oil to drain back to the pan than being pulled up into the combustion chamber. And a new half-shell intake system reduced the number of fittings and seams that can cause pressure loss by casting some parts of the intake manifold into the cylinder head. This version produces 456hp with 479 lb-ft torque available.
And the latest installment of the N63 upgrade is the N63TU3 in 2016. This revision has a lot of improvement since the emergence of N63 in 2008, and those upgrades include: a crossover tube between intercoolers that helps balance the pressure to avoid peaks and to supply a more stable air mass to the engine; ignition coils are pencil-type which are from B63O2, and HFM sensors are not used, so it is also withdrawn and disembarked from the engine, but instead air mass calculations are measured via series of sensors and tables (Valvetronic position, intake pressure, and temperature) to be corrected by the oxygen sensors.
Problems surrounding N63s
BMW will always be a frontrunner in terms of performance and power. And even the best engines suffer from different complications brought by age and mileage. So, if you’re planning to buy an N63 suited engine or owned at least one, more often than not, you are also worried about some problems that might occur with your powerplant. Whether how minor or staggering the issue, it would still put some headache for some reason. Here are some issues that haunt some N63 engines:
First is BMW N63’s Excessive Oil Consumption. Its unquenchable thirst might be due to its engine design, being the turbos were in the middle of the valley, where the heat is concentrated at a certain area of the engine that causing the engine to consume more oil; even leaving the gaskets bone-dry that results in leaks and cracking. Some owners recommend changing the oil every 4000 – 6000 miles and load a few quarts if ever the indicator goes a little off.
The second is the Fast Battery Drain. With BMW’s vision for better fuel consumption, they let the alternator output shut down, which technically saves fuel because the engine does exert effort to spin the alternator. This system, however, reduces charging during normal driving and happens only when coasting. So if you put your foot on the brakes and not letting the wheels spin, this causes the RPM to lower, and alternators cannot charge.
The third is Fuel Injection. N63s are direct-injection engines for which fuel is being fired at high pressure directly into the combustion chamber, making the back of its intake valves prone to carbon build-up, which causes the engine to run awfully due to rough air passages. You may clean the intake ports every 40,000 miles by removing the intake manifolds.
Fourth is the Timing Chain failure. N63’s timing belt is subjected to wear and tear to the valvetrain and may negatively affect its performance that, if not addressed, can lead to ben valves and, down the road, engine failure.
N63 Customer Package
BMW noticed that many customers are having issues regarding these engines, which is why they released the Customer Care Package in 2014. This launch attempted to rectify the issues festering N63s. Good news for BMW as most of the owners and enthusiasts appreciate their collaboration to alleviate some common issues.
N63 is powerful and revolutionary. Being the first of its kind, the integration of hot-vee layout has landed this engine on one of the iconic V8s. Even though some skeptics might argue with its maintenance cost and issues but if you are buying N63s, make sure it is an updated version and check its background.
We hope that we cleared some clouds in your head regarding N63 engines.