The Honda B-series VTEC Guide

Extracting high power from a small capacity four-cylinder traditionally means relying on forced induction or old-school ‘hot-up’ techniques (which can only be taken so far without compromising drivability). But all that changed in 1989 with Honda’s release of the B16A 1.6-litre VTEC. With the advent of VTEC variable valve timing and lift, it became possible to achieve what was otherwise out of reach – a strong high rpm power output without compromising low rpm torque and drivability.

In this article we’ll take a look at the evolution of the groundbreaking Honda B-series engine from its introduction in 1989...

VTEC – What exactly is it? In recent years, Honda has applied the VTEC name to all sorts of variable valve timing systems and it’s become difficult to understand what’s what. But, in the case of the B-series engine, all you need to remember is that it uses the ultimate version of VTEC – there’s variable valve timing and lift. This is how it works... The B-series VTEC system employs three in-line camshaft lobes for each pair of intake valves. During low rpm operation, the two outer lobes - which deliver low-lift and short-duration - control the intake valves via their own set of rocker arms. A third set of rocker arms - which align with the centre camshaft lobes - are left idling during this stage; their movement controlled by a 'lost motion' spring. Then, during high rpm operation, the engine management system locks the centre rocker arm to the outer arms using a hydraulic synchronising pin. This sees the centre camshaft lobe - which delivers high-lift and long-duration - taking control of the intake valves and giving increased engine airflow at high rpm. The benefit of this system is a healthy spread of torque across a wide rev range. Note that the B-series engine achieves its variable valve timing differently to the systems that have recently become common. There is no actuator on the cam sprocket that serves to alter camshaft angle relative to the crank. Instead, the B-series engine achieves its variable valve timing by switching between its dedicated low rpm and the high rpm cam profiles; the cam lobes alter valve opening and closing times as well as lift. Switching between camshafts is a single step operation which creates the so-called "VTEC change-over".

Early B16A

We believe that the first incarnation of the B16A VTEC was seen in the Japanese domestic market only.

In early 1989, the DA6-series Honda Integra was released in RSi and XSi models and debuted Honda’s VTEC variable valve timing and lift system. This innovative technology combined beautifully with a 10.2:1 compression ratio (which was then considered quite high), 16 valve breathing and a PGM-FI engine management system using a MAP sensor. And, with a total displacement of 1595cc, Honda made sure the B16A was eligible for competition in sub-1600cc racing categories. Bore and stroke dimensions are 81 and 77.4mm respectively.

These early B16A VTEC engines generate 118kW at 7600 rpm – an achievement that was hard to believe at the time given Toyota’s high-output 1.6 could muster only 103kW... Like all VTEC engines that were to follow, the B16A’s peak torque output is similar to a conventional engine – albeit it’s reached at much higher revs (7000 rpm). Of course, the use of premium unleaded is mandatory for the little VTEC to perform at its best.

Most Integra RSi and XSi models come equipped with a five-speed manual transaxle that, due to the modest torque output, is closely based on the gearbox used in regular Honda 1.6s. Interestingly, there was also the option for a four-speed auto – an unusual move given the sporty, free-spinning nature of the B16A. Be aware that these early auto-equipped engines are detuned to 110kW at 7100 rpm and 150Nm at 6000 rpm. We imagine that milder camshafts are employed.

In late ’89, the B16A VTEC was spread into the EF9-series Honda Civic SiR and SiRII. Engine output remains at 118kW/152Nm and all EF9 VTEC Civics come standard with a five-speed manual ‘box. A limited-slip diff was also offered as an option.

In 1990, the potent Honda four made its way into the wedge-shape EF8-series CRX SiR. Interestingly, this is widely thought to be the first application of the B16A VTEC – that’s because the lighter and sportier CRX had a much larger impact on the market. The media really started to open their eyes when the B16A VTEC hit the CRX.

These early generation B16As are becoming rare at the import wreckers but, because most people opt for the updated B16A (which we’re coming to), you should be able to pick one up at a good price. All come with a front-wheel-drive transaxle and you’re better off with an engine that was originally tied to a manual gearbox.

B16A Update

Barely two years after its release, Honda treated the B16A to further enhancements aimed at producing more power. The compression ratio was bumped up to 10.4:1, the camshafts were revised and a larger throttle body was installed. We believe there were also some other minor changes and, incidentally, these later-model engines can be identified by the lack of a PGM-FI badge on the intake manifold.

The result of these alterations?

A handy 7kW and 5Nm gain. There was now 125kW at 7800 rpm and 157Nm at 7300 rpm – and, still, there was no complaining about a lack of bottom-end drivability. The tweaked 1991-spec B16A was fitted to the existing Integra, Civic and CRX range. Again, the auto transmission versions (available in the Integra and Civic) aren’t as potent as the five-speed manuals. The same mechanical changes were applied but, regardless, output is ‘just’ 114kW and 153Nm.

In the same year (1991), the curvy EG6-series Civic was phased in but it was the final year for the B16A powered Integra - the next model Integra stepped up to a 1.8-litre engine.

In the following year (1992), the new-look CRX Delsol appeared on the market to replace the wedge-style design. The 1992 CRX was the first VTEC powered car to arrive in Australia but, unfortunately, the compression ratio was reduced to 10.2:1 and output slipped to 118kW/148Nm. The same 118kW/148Nm engine was also employed in the Australian-delivered Civic VTi-R from 1995.

The B16A engine remained essentially the same until in was progressively dropped from the line-up in the late ‘90s

The wildest version of the 1.6-litre VTEC – the B16B – was released in the Japanese market Civic Type R produced from 1997. And this is one heck of an engine for something with full factory backing... The Civic Type R’s B16B engine runs a startlingly high compression ratio (11:1), polished low-friction internals, revised crank and rods, wilder camshafts and bigger valves. Engine management calibration is also remapped to help achieve a stunning-for-a-1.6 136kW. Peak power is reached at a sky-high 8200 rpm and peak torque (160Nm) is only a little lower on the tacho at 7500 rpm...

As far as we can determine, this is the most powerful naturally aspirated 1.6-litre engine ever put into production. Certainly, the Honda 1.6-litre VTEC disappeared with a bang!

These Type R B16B engines are extremely rare at the importers and, yes, you will pay a large wad of cash for one. On the other hand, the garden variety late-model B16A can be sourced quite easily and, as a result, you’re in a good position to negotiate a price.

B18C

When the B16A powered Integra was axed during 1991 there was a brief hiatus until the release of the next generation hi-po Integra – the 1993 DC2/DB8-series Integra VTEC.

The new series Integra is slightly larger than the previous model so it’s no surprise that Honda decided to give it an increase in engine displacement. And here enters the 1.8-litre version of the Honda VTEC four – the B18C.

Despite its 200cc advantage (which is achieved through a longer 87.2mm stroke), the B18C maintains a very high level of tuning - the compression ratio is 10.6:1 and the rev limiter is set to 8200 rpm. This wonderful engine has the same revvy nature of the original 1.6-litre VTEC but boasts substantially greater torque through the range – there’s 132kW at 7600 rpm and 175Nm a 6200 rpm.

As previously, an auto version of the Integra VTEC was offered in Japan with reduced engine output. For those who can’t be bother changing gears manually you’ll miss out on 7kW.

In Australia, we received the 1.8-litre B18C VTEC engine in the Honda Integra VTi-R. Again, a relatively mild compression ratio (10:1) is largely responsible for reducing power - its 125kW output is matched by the contemporary Japanese-spec 1.6-litre...

Nineteen ninety-five saw the Japanese release of the built-to-race Integra Type R along with its ultra high-output B18C VTEC.

No matter how you look at it, the Type R-spec B18C engine makes the popular 2-litre turbo engines look silly. There’s no need for forced induction when you’re running a remarkable 11:1 compression ratio, low-friction internals, polished ports, wilder VTEC cams, a high-flow intake manifold and throttle body. In the old money, this engine screams out 200 horsepower (147kW) at 8000 rpm and there’s 181Nm of torque. Now that’s an engine, eh? No need for aftermarket tuning here.

Australia was fortunate enough to take delivery of the Integra Type R in 1999 but, yes, it was detuned. But only slightly. It appears that conservative ECU mapping is responsible for trimming off 6kW – there’s still more than enough grunt for the car to leap to 100 km/h in around 7 seconds.

Want an Integra Type R B18C engine? Well, unfortunately, these are extremely rare and retailers can almost name their price. A more cost-effective option is the base Japanese-spec B18C which makes 132kW – these are in good supply and you can easily add more power with aftermarket parts. We reckon this engine is the hottest choice for second-hand engine buyers.