Nissan RB26 engine: Everything you need to know

Thanks to decades of humdrum Australian family cars powered by inline six-cylinder engines, there’s a temptation to associate the straight-six with the mundane side of four-wheeled transport. 

But the reality is that the world has seen some truly fabulous performance-car engines with just such a cylinder layout.

Our own locally-developed Ford Barra Turbo is one. So is Toyota’s vaunted 2JZ. And without any doubt at all, the Nissan RB26 engine is another. In fact, the RB26 vs 2JZ debate never fails to elicit a response among fans of Japanese tuner cars, proving the Nissan’s credentials.

Read More About Nissan Skyline

Toyota 2JZ engine: Everything you need to know Engine capacity - what does cc mean? Barra Engine: The Truth About the Ford Barra Engine

Not only has the up-spec version of the Nissan RB powered one of Japan’s most revered supercars, the engine has even powered a Bathurst winning car and absolutely dominated global touring-car racing for years. 

In fact, it was so good, the demise of the inline RB engine for the most recent version of Nissan’s GT-R in favour of a V6 caused widespread angst among the faithful.

Nissan’s broader RB family of engines was launched in 1985 and ran until 2004, along the way powering everything from mild family sedans and wagons to the monstrous Skyline GT-R dynasty and everything in between. 

Ranging in capacity from 2.0 to 3.0 litres, the RB series used a cast-iron cylinder block while the RB26 head was made from aluminium alloy. 

The naturally aspirated RB30 produced 114kW/247Nm. (image credit: Haltech Support Center)

Both single and double overhead camshaft layouts were used (driven by a toothed rubber belt) and both two and four valve per cylinder arrangements were available.

Along the way, all the inline six’s traditional benefits were on tap, including a narrow engine for packaging and perfect primary balance to aid revving ability and smoothness. 

In fact, peer inside an RB26 engine bay and even traditional mechanics can makes sense of what they see beneath the engine cover. 

Throw in the inherent toughness and tuneabilty of the Nissan RB, and you had the basis for an engine that absolutely defined Japanese performance at that time.

The R26DETT produced

Globally, the RB26 was the most common offering with its 2568cc displacement (2.6 litres, hence RB26) courtesy of a bore and stroke of 86.0mm and 73.7mm respectively, making the bottom end extremely undersquare. 

Power, in this normally-aspirated form, was 162kW and 245Nm. Various other tunes were available including turbocharged and naturally aspirated layouts with a range of outputs.

But it’s the engine in Godzilla trim that everybody remembers. Dubbed the R26DETT, the engine first seen in the R32 Nissan GT-R also went on to power the R33 and R34 GT-R models as they came and went. 

Godzilla!

Other RB26 cars included the highest-spec Nissan Stagea station-wagons.

Over and above the basic RB family architecture, the RB26DETT ditched the standard fuel-injection for specific RB26 individual throttle bodies (one for each cylinder). 

The turbocharging was next-level, too, with a pair of turbos working in parallel with ceramic turbines, running 10psi of boost in production form. And the trick bits didn’t stop there. 

When discussing import vehicles most people think about Japanese car imports Australia fell in love with in the late 1990s like Skyline GT-Rs.

The high-spec RB26 pistons featured cooling channels under their crowns to control internal temperatures, the exhaust valves were sodium filled, the standard RB26 crank was fitted with extra counterweights and I-beam connecting rods were fitted. 

All those measures helped the engine not only produce prodigious amounts of power and torque, but also gave it the ability to hang together for a 1000km (and more) race.

So, why did Nissan claim just 206kW for this version of the engine? At that point in time (the late '80s and early 1990s) the Japanese manufacturers had a gentlemen’s agreement with the government that they wouldn’t push a production-car engine beyond that level of performance. 

NISMO homologated the R33 for racing at Le Mans with the 400R.

The agreement is now dissolved, of course, but even back then, the amount of RB26 horsepower being claimed Nissan (and Toyota for its 2JZ) were seriously questionable numbers.

What’s more likely is that the heavy-duty and high-tech specification of the RB26DETT had it making quite a bit more than 206kW. But the other result is that the engine was also spectacularly reliable and would respond favourably to much higher levels of boost. 

Some early versions of the engine with the standard RB26 oil pump experienced failures at sustained high rev operation, but a redesigned pump fixed that as a running change. 

The ceramic turbine wheels in the turbochargers also suffered in constant high-speed, high-boost conditions and, ultimately, for racing, Nissan’s racing arm, Nismo stepped in and produced the most hard-core RB engine of the lot. 

That engine was dubbed the RB26DETT N1, and it was the engine that altered the course of touring car racing around the world.

This was the engine that won Bathurst in 1991 and again, controversially in 1992 after the race was declared 18 laps early in the face of a torrential downpour. 

The R32 GT-R dominated the Australian Touring Car Championship (ATCC).

Nismo’s changes to the engine for touring-car racing included a different cylinder block, bigger RB26 injectors, a more accurately balanced crankshaft, better oil and coolant passages, improved pistons and rings and upgraded turbochargers with, crucially, stronger steel (rather than ceramic) turbine wheels.

In Australia, the RB26DETT was sold here in the very limited number of R32 Skyline GT-Rs that were imported. We never officially saw the R33 or R34 GT-Rs, meaning that the member of the RB family Aussies are most familiar with is the RB30 in naturally-aspirated form.

This was the engine that powered the locally-built R31 Nissan Skyline which was made in Melbourne from 1986 to 1991 as well as a locally-tuned version called the Skyline GTS which featured a warmed over RB30 with a different camshaft and exhaust system. 

The engine also found its way into an entry-level version of the GQ Nissan Patrol, which ditched the Skyline’s electronic fuel-injection for a carburettor and was a budget-beater in every sense.

The RB30 in-line six found its way into the Patrol to create the ST30 variant.

But the naturally aspirated RB30 also powered a mainstream Holden family car, and that’s a large part of the reason it’s so revered here. 

As 1986 and mandatory unleaded petrol approached, Holden discovered that making its old six-cylinder engine compatible with ULP would cost a lot of money with no guarantee the result would be worth the effort. 

So, it went shopping globally for a new engine and wound up at Nissan in Japan which agreed to sell it a batch of the RB30 engines for the car which became the VL Commodore. 

The step up in performance, refinement and economy was a huge one, sufficient for the VL Commodore to be remembered very fondly.

But there was another reason the RB engine was so important to Holden. And that’s because Holden also managed to arrange the purchase of a batch of turbocharged RB30s (the RB30ET) which used a single turbocharger, single overhead camshaft and two valves per cylinder. 

With a Garrett T3 turbo and 250cc fuel-injectors, the RB30DET pushed out 150kW/296Nm. (image credit: Haltech Support Center)

As such, it made 150kW of power at a time when that was unheard of and instantly became Holden’s performance flagship. Everybody from boy racers to state Highway Patrols loved the VL Turbo and it remains a local legend. 

Curiously (and it had a lot to do with the engine-supply contract between Holden and Nissan) Nissan locally didn’t build a turbocharged Skyline using the same powerplant, preferring to produce the modified non-turbo engine in the Skyline GTS.

In Skyline form, the RB30 proved very robust and reliable as it did in the Holden, the only exception being a tendency to overheat in the latter if the cooling system wasn’t bled correctly. The lower radiator top tank of the Commodore was the culprit, and in the Skyline, with its higher top tank, the issue never arose.

While the road-going R31 used the RB30, the Group A racer used a turbo RB20 engine instead.

These days, the RB30 might be a bit long in the tooth, but it’s still being modified by a hard-core of enthusiast who appreciate its inherent toughness and tuneability. 

That’s particularly true of the 2.6-litre variant and RB26 cam and RB26 turbo kits are widely available from a variety of aftermarket manufacturers. 

The other turbo trick is to swap an RB26 twin turbo to an RB26 single turbo which sounds like a backward step, but can aid reliability and, assuming the correct size turbo is fitted, performance can be increased at the same time.

Many modifiers also like to allow for more lubricant, and that’s made possible by extending the depth of the standard RB26 sump.

If you’re looking for an RB26 for sale, they’re pretty thin on the ground in Australia, although specialist importers might be able to help. 

As a quick guide to identification, the RB26 valve covers on the early (R32 and R33) GT-Rs were black, while the later R34 variant was red. 

The RB26 can be easily modified to make even more power.

A definitive second-hand RB26 price is impossible to gauge, however, and it will all depend on what specification it is and what sort of life it has led. 

In Australia, the RB30 vs RB26 argument takes a weird turn because even though the RB30 is a lower-tech engine, it’s vastly more available and affordable. 

That may change as time passes and the VL Commodore becomes more collectible than it is now, but right now, a rebuildable RB30 will be a fraction of the asking RB26 price.

Meantime, so popular is the RB26, that a handful of years ago, Nismo actually started remaking genuine RB26 components, including the cylinder block and head. Tuners of the world rejoice.