Legendary Engines: The 1.6 Twincam

•July 28, 2011 • 2 Comments

I’ve been wanting to write an article about the venerable Japanese twincam engines for a while now. I was initially attracted to the Japanese car scene through magazine features of large turbo-charged behemoths such as the R32 Skyline and the JZ-series Supras. As I delved deeper however, it was the smaller engined cars that really grabbed my attention. In popular culture these small-but mighty vehicles enjoy a reverence on a par with their substantially more powerful brethren. More often than not, the engines behind these cars were 1.6 litres, twin overhead cammed with only 4 cylinders. Three such engines really stand out, the 4-AGE from Toyota, and the ZC and B16A from Honda.

The 4-AGE was first launched in 1983 and was a joint collaboration between Yamaha (who designed the cylinder head) and Toyota. It was one of the first 4-cylinder engines to combine fuel-injection with the 4-valves per cylinder layout and dual camshafts (one operating the intake valves, the other the exhaust).  The engine was immortalised through its usage in the legendary AE86-chassis Sprinter/Levin RWD hatchbacks. Initially it only produced a lowly 120hp and lacked the later sophisticated variable valve timing of the Honda VTEC engines. It did however feature the innovative T-VIS system, which had secondary butterfly valves in the intake manifold that opened at 4200rpm, and helped low down torque without sacrificing the need for greater air volume at higher RPM’s. There were numerous incarnations, including the ‘Red-top’ version, the most powerful of the 16 valve 4-AGE’s. For this version, produced in 1989, Toyota bumped the compression ratio to 10.3:1 and ditched the T-VIS system. In this guise the engine was rated at 140hp. These early engines were not only used in a wide-variety of Toyota production vehicles, the AW11 Mr2 and the N-series Corolla Gti’s but also retro-swapped into a whole host of other cars, such as the older KE70 Corolla, the KP61 Starlet and even non-Toyota’s, in particular the ’74 to ’87 Daihatsu Charmant. The 4-AGE survived until 1998, by which time it had evolved into a 165hp heavyweight. Toyota increased the number of valves per cylinder to 5 (20 valves in total), introduced VVTi (Variable Valve Timing) technology and even went so far as to use 4 individual throttle bodies on the intake side.  This highest spec 4-AGE is colloquially known as the ‘Silver-Top’, due to its silver camshaft/head cover.

Honda introduced its own 1.6 litre Twincam engine in 1984 and shared very similar specifications with Toyota’s 4-AGE. The ZC engine, again, had a 4-cylinder layout with 4 valves per cylinder with twin overhead camshafts. It was rated at slightly more power (130hp) but there were many variations both in Japan and Europe/USA (where it bore a D- series stamp). It initially featured in the AT Civic and AS CRX Ballade models with the ‘Brown-top’ designation but later also featured in the EF3/7, Civic/Crx and the DA Integra as the ‘Black-top’. The engine was effectively shelved in 1991 after the resounding success of the more powerful B16A engine. It was however, reintroduced for a brief factory run on the limited edition EG5 Civic Si which commemorated both Honda’s 20th Anniversary and the fact that the new EG-series Civic won Japans ‘Car of the Year’ award for 1991-92.

This is not the 1.6 engine for which Honda became famous for though, instead that accolade goes to the B16A. This engine was the first of-its kind to feature the pioneering VTEC system. VTEC operates by switching the camshaft profile at a pre-defined point (often at around 5600rpm) to a much more aggressive one. This means that it negates the poor low-rpm characteristics of high-lift camshafts and effectively creates a dual-engined vehicle; one that is happy to run at 1500rpm through town, with enough power to satisfy the humble commuter, whilst offering lightning-quick performance at higher rpm. In its initial incarnation in the DA6 Integra Xsi the engine produced 160hp (1st Generation), whilst later models such as the EG6 Civic SiR and Ek4 Civic SiR had power bumped to 170hp. I have detailed the differences between the two generations in my EG6 Guide. The first generation engine is more commonly associated with the EF8 CRX and the Civic equivalent, the EF9. This is because of the DA6 not being released in Europe, and America’s lack of enthusiasm for small sports cars preventing many of the more powerful engines being released there. In its 2nd generation guise, the B16A produced an astonishing 106hp per litre,  unmatched by many of its contemporaries, and still impressive nearly 20 years on. Indeed, if we compare it to the Ferrari F355 of the same time period, its 3.5 V8 only produced marginally more @ 109 hp per litre. It goes to show what an important breakthrough the B16A was when Honda decided to use the VTEC system on its NSX supercar in 1991, and that 20 years on, nearly all small engine vehicles use some form of variable valve timing.

Work Reissues the Iconic CR-01

•May 3, 2011 • Leave a Comment

Work wheels have followed in Enkei’s footsteps by reissuing one of their discontinued back-catalogue. As part of the nostalgic revival that the Japanese car scene is currently seeing, popularity of older wheel designs has soared. I guess this is in part down to the uninspiring range of new ‘eco-warrior’ cars that Toyota, Honda et al. seem to be focusing on now. The ’80s and ’90s are quickly being seen as the pinnacle of Japanese automotive history and the racing  scene (legal and illegal) that was inevitably spawned.  Work have recognised one of the smaller cult followings in the racing underworld: Kanjo racers, on whom I wrote a short piece back in March. The CR-01 has recently become synonymous with the EA, EF and EG Civic chassis’. Most recently promoted by the Temple Racing/ Osaka JDM team.

Kanjo Racers

•March 8, 2011 • Leave a Comment

I’ve been aware of these guys for a while now. Many of you will have probably seen the JDM Insider video surrounding ‘kanjo racing’ (it’s available on Youtube). A mixture of awe and incredulity is the natural response to seeing a host of cars racing at speeds well over 100mph in heavy traffic, and yet you feel guiltily excited by it all. I don’t know what it is, whether somehow these racers come across as somehow being ‘purer’ or in some way more legitimate in their law-breaking ways, but you approve of it nonetheless. For me the young guys behind the cars embody everything I love about the ‘JDM’ scene. Grassroots racing, low budget, backyard built but a passion unmatched and often totally missing in magazine-feature worthy, or shop built vehicles.  Often the recipe for building these cars is old-school (used and cheap) wheels, coilovers, straight-piped exhausts, stripped and caged and almost always complemented by incredibly sticky tyres. Semi-slick Yokohama AO48’s seem particularly popular. The car below, part of the Osaka JDM/Temple Racing team, features these tyres matched with Mugen CF-48 wheels including the rare disc covers. Surprisingly, engine swaps are rare, as is extensive engine tuning. Many of the cars are either the 3rd generation E-AT, or the 4th generation EF, many sporting the non-vtec ZC engine.  This is testament to the kind of racer behind the wheel. These often rootless youths are on lower incomes and many struggling to buy into the prohibitively expensive property ladder. They are brought together and find unity and identity through their love of driving. Of course, some teams embody this more than others. Team Late Risers are probably the most famous and feature prominently in the JDM Insider video.

The Osaka JDM/ Temple Racing EF9:

The EG6 Guide (Pt.III) – The SiR-S

•February 27, 2011 • 1 Comment

Well, I promised a small guide on the SiR-S as it’s another one of those areas that pretty grey when it comes to accurate information. I myself own one, and so over the past two years I’ve done a fair bit of research into them.

Production dates: 1992-1993 (production numbers are unknown however, estimated between 3000-5000).

This means that the S was only ever a Zenki model, I have seen a Captiva blue Kouki-spec ‘S’ popping up on a number of US forums, it isn’t an S however. Buying the rear decal is pretty easy!

The SiR-S spec:

-Unique ‘DOHC Vtec’ decals on the doors

-Champagne coloured EG6 alloys

-Keyless Entry (It has a small retangular sensor on the driver’s door handle)

-Armrest as standard

-Black/Charcoal Zenki interior

-Momo Steering wheel and leather gearknob

-Choice of three colours: Granada Black Pearl, Milano Red or Lausanne Green.

That’s it, no mechanical differences, and it didn’t have any other optional extras as standard. Contrary to popular belief, the S didn’t have an LSD as standard.

Heres a few shots:

My personal SiR-S on OEM optional EG6/EG2 wheels












Original JDM SiR-S brochure














Standard SiR-S














Momo SiR-S wheel

Top Setup Civic

•February 15, 2011 • Leave a Comment

One of my favourite EG’s,  owned by Charlie Rhyu. He intially turned up only to watch the heats for Hot Versions first American Touge DVD. After the Vishnu Evo dropped out with headgasket problems, Charlie was approached to see whether he wanted to audition the Civic as a last minute entry. He went on to blitz the competition. Just goes to show how much weight plays in the performance of a vehicle.

The EG6 Guide (Pt. II)

•January 13, 2011 • Leave a Comment

In Part 2 of my guide I will be focusing on mechanical spec and the associated options that were available from the factory. Again there seems to be debate surrounding differences between the SiR and the SiR-II and, indeed, the SiR-S. I will start off by saying that there is no mechanical differences between them. The engine is the same, the suspension is the same etc. The differences between the ‘trim’ levels are purely that, cosmetic- i.e. the interior trim colours and also the ‘II’ opened up a lot of the options available.

Engine: B16A- 2nd Gen (only non-JDM vehicles have another number after the A. All Japanese spec engines have a four character code). 170PS (168hp@ 7,800Rpm). 8200rpm Redline, 10.4:1 Comp Ratio.

The engine differs from the 1st generation B16A (as found in the EF8 and EF9) in the form of different camshafts. This accounts for the 10hp bump in power. The redline was also raised to 8200Rpm. The engine differs from UKDM and USDM models via the pistons. The B16A uses P30 pistons which raise the compression to 10.4:1, compared to 10.2:1 (PR3 pistons) in the B16A2 etc of the same era.

Gearbox: Y21 (optional Visous Coupling Differential, i.e. ‘LSD’), Hydraulic Clutch.


1st: 3.230

2nd: 2.105

3rd: 1.458

4th: 1.107

5th: 0.848

Final Drive: 4.400

Mechanical Options:

-Automatic Transmission: As it sounds, a self-shifter option was available on the basic SiR, not on the II or the -S.

-‘LSD’: Technically, the optional differential isn’t a true Limited Slip Diff, it doesn’t work on the principal of slipping clutch-type plates to lock out one wheel for traction. It is actually a Viscous Coupling Differential that uses Fluid to approximate a similar effect. There is no way to 100% accurately check for the presence of the LSD just by looking at the car/gearbox. The gearbox cases were not stamped like early Y1 boxes, or ink printed like later S80’s gearboxes. There should be a small ‘LSD’ sticker underneath the rear wiper however. Dissembling the driveshaft and physically checking the differential is the only way to check.

– TCS: Traction control, this option would necessitate the ABS option, as it works off the same pump. An either/or option with the LSD. Has a On/Off button on the centre console.

-ABS: Self-explanatory. I believe this was an option up to 93, and then standard when the car was revised in 94.

Brakes: 262mm/242mm discs, optional ABS 91-93. 7/8 Master cylinder, upgraded to 15/16 in ’94 when ABS was introduced as standard fit.

Suspension: Not much to say, a front strut brace was standard, no options for further bracing or sports suspension. It was a sophisticated double wishbone design however, which Honda no longer use on the current Civic (FD/FN). The JDM EG6 had ‘ball’ type lower rear control arms, the same as the DC2 Type R. Non-JDM EG6’s had the ‘fork’ type.

Sway bar specs are:

Front: 21mm

Rear: 13mm

LSD Sticker denoting the presence of the option Differential

The TCS button located on the dash. Next to EG9 'Door Lock' button. You can see underneath that the small amber button on the mirror adjuster is for heated mirrors.

The EG6 Guide (Pt.1)

•January 12, 2011 • 2 Comments

I’m currently compiling what I’m hoping will be the comprehensive guide to JDM EG6’s. I’ve been on numerous forums recently, helping to identify imported EG6’s and work out the, frankly bewildering spec variations and options. Despite only being made in the early 90’s, much of the information surrounding the cars is inaccurate, patchy and at best fairly speculatory .

Here’s some basic facts to get it going, I shall update this post as I develop the guide:

JDM (Japanese Domestic Market) Honda Civic SiR:

Chassis: E-EG6

Production Dates: 1991-1995 (officially 1992-1995). Split into Zenki models 91-93, Kouki models 94-95.

Different Spec Levels: SiR, SiR-II, SiR-S (92-93 only, limited run, unconfirmed numbers)

Available Colours (code) and Interior Trim Choice:

Cloth choices are noted first, after the /  is plastics colour

Cloth: B=Beige, C=Charcoal, P=Purple, Y=Yellow

Plastics: G=Grey, D=Dark

All Kouki models came with Dark Plastics and Black+ Red check cloth. This is what is wrongly referred to as the ‘Anniversary Edition’ interior in America. It is just the standard 94-95 revised interior.

-Milano Red (R-81)- B/G on SiR, C/D on SiR-II, C/D on SiR-S *

-Captiva Blue Pearl (B-62P)- B/G on SiR, P/G on SiR-II

-Granada Black Pearl (NH-503P) – P/G on SiR+ SiR-II, C/D on SiR-S *

-Lausanne Green Pearl (G-71P) – Both specs C/D (plus  SiR-S) *

-Carnival Yellow (Y-53) – Both specs Y/G

-Frost White (NH-538) – Both specs P/G

-Pewter Grey (NH-537M) – Both specs P/G

-Vogue Silver Metallic (NH-550M) – Both specs P/G

-Tahitian Green (BG-28P) – Unknown

*These three colours are the only colours that the SiR-S was available in, FACT. I will be doing a small section on the SiR-S later.

Zenki Charcoal: Note the unusual headrest design, changed in '94.

Kouki: Ignore the racing seat, note the headrest and checkered cloth.

Yellow Zenki