The genesis of the Jaguar V8

There was a time when ‘Jaguar’ and ‘V8′ could not be uttered in the same breath, which is odd when you consider the majesty of the Daimler 2.5 and 4.5 V8s used since the ’60s.

But by the end of the ’80s it was becoming clear that the weight of the gorgeous Jaguar

Potent as the V12 was, it weighs about 350kg on its own! As I found out when I built this XJ-S...

V12 was just too much, plus its enormous physical size was hampering car design, particularly for crash performance where you need some crumple zone rather than solid engine. The engine was revolutionary in the ’70s, but in the ’80s the labour intensive assembly and expensive parts was costing the company more than it was making. For the last years of the XJS the V12 was not even on the official brochures, it was only its legend that was keeping sales alive.

The AJ6 and AJ16 6 cylinder engines were making almost the same power and saved about 120kg which made a huge difference to the cars handling. But even this engine was showing its age.

New shorter engines were needed in order to allow sufficient room for an effective crumple zone. The engines needed to warm up more quickly, for both customer comfort and the ever tightening emissions regulations. This needs more precise cooling in the heads and block plus the use of considerably less metal. The piston ring system needed to control the oil much more accurately and piston friction had to be lowered. Indeed, friction throughout the engine needed to be reduced to meet the fuel economy and emissions targets.

With these issues in mind, a number of alternatives were looked at in the late ’80s, including a V12 derived V6 with the lost power being returned by using a brace of turbos. Another V6, an Orbital 2 stroke engine which gave the same number of power strokes per rev as the old V12 engine, was looked at but oil control and refinement never quite met the targets. They even looked at a number of engines from other companies, which could be bought in without the huge cost of developing their own engine.

During the dreaded BL days there had been some discussion of using the Buick derived Rover V8, which had substantial advantages in terms of weight (in fact it weighed half as much as the V12), cost and size. Unfortunately, most of the advantage came from the fact that it was relatively thin walled and so suffered in refinement a little. But in reality this could have been developed out, as was the case in the final fling of the Rover V8 inside the P38a Range Rovers.

But that venerable V8 was itself a relic of the ’60s and ultimately suffered from the same issues as the old Jaguar engines, in terms of efficiency and emissions. It also struggled to meet the power demands of modern cars, the 4.6 version only putting out 220bhp.

So the bold decision was made to design a completely new Jaguar engine, one that would meet the forthcoming challenges of regulations and customer expectations. Originally code named the AJ12, the project used a single cylinder research engine to examine a number of different combustion chamber, cylinder head/ port and cam options. This data showed that a 500cc cylinder with 26 degree ports and a four valve configuration gave the best economy and performance for Jaguar applications.

Although AJ12 never resulted in a physical engine, the data was used to study a modular engine design concept, concentrating on a 4 litre 8 cylinder and a 3 litre 6cyl, but also looking at a 2 litre 4 cylinder, a 5 litre 10 cylinder and a 6 litre 12 cylinder engine. This would require some rather sophisticated machinery to be able to make all those variants, sharing common components such as piston and valves but little else. As the analysis data grew, it became clear that the complexity of doing all those variants would be crippling, so it was decided to concentrate on 6, 8 and 12 cylinder V engines. Thus the project now became known as AJ26, 26 being the sum of 6, 8 and 12.

The Jaguar V8 would also make a damn fine race engine...

 

But this would be hugely expensive, the fuel bill alone for testing engines runs into millions of pounds per year. At this time Jaguar was privately owned and as such there was simply not enough spare cash to invest in new products. What was needed was an owner who could suffer the financial hit in the long period between investment and return.

When Ford became interested in buying Jaguar, it was only natural to see if one of their many engines would fit the bill. Indeed it was not uncommon for Jaguar owners in the USA to retro fit a Yank V8 so there was some precedence for this already.

But work had already started on the fledgling Jaguar V8 and the Whitley team, lead by Dave Szczupak, were passionate about seeing it through, they had looked at all the requirements and designed something that would give the legendary levels of Jaguar refinement and power whilst being small, light and efficient. But there would be a long road to go, from a concept to a fully customer ready production engine. Typically it takes around 7 years, that’s a long time to ask an investor to wait for a return.

Ford looked at the arguments for both Ford engines and for the new Jaguar engines, after all the data was analysed and the requirements understood, they decided to invest the millions needed by Jaguar to make their own new engine. But this would be dedicated tooling for just the V8, all other variants were not to be.

The first year had been largely given over to defining the requirements, the specifications for each part of the engine such as how much heat goes into the coolant and the oil, how much force is needed to turn the engine over, valve train stiffness, noise levels as well as the major things like the power and torque levels.

This had lead to the basic design, this was put into the new computers and virtual tests run to establish the best coolant flow paths, the best inlet and exhaust port shape, the cam profiles and the such. A huge amount of data was produced and analysed, without making a single engine. Somewhat different to the early days of the V12 when development was a matter of calculated guess work and then lots of test engines trying it all out.

The calculation gave most of the answers, but some elements still required real world testing. To this end some elements of the new engine were experimented on in isolation, using a current production ‘slave’ engine as a base, giving rise to some odd reports in the press of the new engine being based on this that and the other engine. For example, in order to try different bore and stroke combinations on the single cylinder rig, the engineers looked about for existing parts from all sorts of manufacturers, at one point it was using a Peugeot piston and a Mazda con rod!

The first V8 engines were run on test beds in late ’89 and the first car to receive one was an XJ-S, one of the cars that had just finished being used to evaluate the twin turbo AJ16 in fact. As is always the way with the first ever engine installation, nothing fits, mounts, hoses, air intake and exhaust manifolds all had to be fabricated for the job. Steve, one of the mechanics on the job, recalls ‘they gave me a bag full of exhaust tube and various bends and told me to get on with it’. At the end of ’90, after a couple of weeks of trial and error fitting work the first 4 litre V8 Jag burbled into life and was universally admired by the small select audience of management privileged enough to see it, particularly in America which was a crucial market.

It weighed about the same as the old 6 cyl but had more power and a greater spread of torque, thanks to the new variable cam timing system. But there was a small problem, it didn’t sound like a ‘Jaguar’. Although very appealing, the V8 burble sounded like any normal mid size car in the USA and part of the Jaguar magic was the very high levels of refinement and quietness. Sound is such an emotive thing and much debate was had as to what the new engine should sound like, eventually the decision was made to make it quiet and an enormous amount of work went into designing complex intake and exhaust systems. It is interesting to note how this has changed now such that the current XKR even has a device built into the bulkhead to help you hear the engines magnificent growl.

The first car I drove with the new V8 was an XJ40 in about ’93 at the Ford research centre in Dunton, Essex. The car was based on the XJ12 body, code namedXJ81, which had completely new metal work in front of the bulkhead in order to accept a V engine. This car was bristling with new technology, it had one of the first electronic throttle systems and this particular car had a manual gearbox but with an automatic clutch. As you shifted gear the systems would move the throttle and clutch so as to give you smooth gear shifts. It was marvellous to drive but ultimately it was easier to just use one of the excellent ZF 5 speed auto gearboxes instead.

Its interesting to note how Jaguar has had a history of technological innovation, and how right from the start Jaguar was showing Ford new things. In return Ford showed Jaguar how to massively improve production processes, improving quality and reducing costs. This relationship is continuing to this day, I am pleased to say, with both sides benefiting.

As the engine developed, the early tunes were used to check and refine the basic performance and emissions characteristics. Then cars were used to tune the transient response, that is to say how the engine responds to acceleration, deceleration and gear shifts. This is always a very difficult balance between good drivability and good emissions, a slightly rich fuelling on acceleration give very good drivability but will fail emission completely on hydrocarbons alone.

The new XK was launched with the revised 4.2 V8, a swansong for the first generation V8.

 

Part of the solution was to ensure the automatic gearbox control system ‘talked’ to the engine control system. This kept the throttle, fuel and spark precisely in tune with the change in engine speed during the shift, allowing the engine to anticipate the changes rather than have to react to them after the fact.

After the engine had received a good stable tune, it was time to test it in all the harsh climates it would face in the real world. Traditionally this involves driving it in the Arctic and in the deserts of Arizona or Africa. But now tests could also be done in Fords climatic test chambers which drastically cuts down the development time and expense. As well as cold and hot climate tests, the new cars had to be tested in extremes of damp to check the corrosion resistance of the components and all the wiring. Then there is the rough road testing, both on specially prepared test track with a range of harsh surfaces, and on shake rigs where computer controlled hydraulic rams try to shake the car to pieces. In short, a lifetime of use and abuse is concentrated into a matter of months. By the end of ’94 a huge amount of data had been produced and all the necessary changes had been made, the results were looking very good indeed.

After this year of climate and durability tests, the final tweaks could be made and then it was time to start running the cars at government approved test centres to get the various certifications needed to sell a new car. At the same time further tests were re-run in house just to confirm that the final version was working as expected.

In parallel to all this development, the production plant was tooling up. First prototype tooling is made and the whole assembly process is tested, any special tools or assembly methods are identified and the first set of workers are trained. The first few test cars were built this way, as were the cars eventually used for the journalists to drive at the launch in ‘95.

The cost of production tooling is huge, the Bridgend AJV8 plant cost Ford £125 million. So it was vital to be certain that everything was right before the orders were placed, this could only happen when all the test data was in and all the tweaks had been tested. This is still true today and is one of the reasons it takes so long to get a new idea into production.

Land Rover with Jaguar V8 power, a rather good combination in my opinion.

 

So, in ’96, seven years after the project started, the first XK8s were sold with the all new, entirely Jaguar, V8 engines. A new era had begun.

The original 4.0 litre V8 went through many detail revisions, and endured the dreded Nickasil debarkle that struck many alluminium bored engines of that era. All the lessons learnt were rolled out together in the later 4.2 litre version of the engine, this unit has a reputation for toughness as well as performance and has been raced with some success too. When Land Rover joined the group it was a natural choice to replace the less than reliable BMW V8 with the trusty and powerfull Jaguar unit. In Discovery it was stretched to 4.4 litres in naturally aspirated form but was left at 4.2 for the supercharged variant, 400bhp seemed perfectly sufficient for a Range Rover back then…..

As with all technology in this rapidly changing modern world, eventually it needed a rethink to regain ground lost to competitors who had brought out engines with the latest innovations. The very name ‘Jaguar’ conjures thoughts of tradition and heritage, but it is easy to forget that a fundamental part of that tradition and heritage is innovation; pushing the boundaries back and surprising the car-buying public. In the 70s and 80s, arguably they made the world’s only mass production V12, and at its launch the XJ6 set new standards in refinement and performance coupled with superb looks and all at a very reasonable price. And whatever you may personally think of the XJ-S, it was a very bold move and still has a very strong following.

The all new AJ-V8 GenIII five litre V8 engine demonstrates the continuation of that innovative tradition, capable of delivering over 500 bhp in a selection of very civilised luxurious cars. And as a demonstration of the engine’s strength, a basically standard engine, a tad over-boosted in a slightly modified XF-R was driven at 225.6 mph on the iconic Bonneville salt flats, faster than the XJ220 super car.

It is interesting to draw a comparison with the magnificent old Jaguar V12, intended to provide approximately 20% greater performance than the 4.2 XK six cylinder engine of the time.

In a similar way, the new AJ-V8 5 litre replaces the 4.2 V8, and pushes power levels up by similar amounts; from 420 to 510 bhp for the R version. However, some things are radically different this time round; the new larger engine manages the rather impressive trick of being significantly more economical than the engine it replaces. An astonishing achievement but absolutely essential in today’s, also radically different, environment.

The V12 was also very advanced for a road car engine at the time, in both its concept and manufacture; it was all alloy and designed for fuel injection from the outset, although they were forced to run carburettors temporarily on the E Type. By comparison the new V8 also uses the latest materials and sports an advanced fuel injection system which heavily influenced the engine design, specifically the cylinder heads with a central fuel injector in each combustion chamber.

From E Type to XJ supercharged 5.0 V8, innovation lives on.

 

The injection concept was proved out before any prototypes were made, on a highly modified current production engine taken out to 4.5 litres. The first real prototype engines were created in 2004 and were immediately and relentlessly tested in engine dynamometers, where each engine can be tested in isolation under precisely controlled conditions. Some engines did specific tests such as trying to deliberately foul the spark plugs, or push the performance limits, and others were run on durability cycles designed to stress components to the max, many a time I walked past a test cell where the exhaust manifolds were glowing bright orange as an engine was run at full tilt.

It is of course the people that really make a company, such as the crack team of expert technicians who build and prepare engines ready for testing, often covered with so much complex test equipment that the engine is totally obscured. Or the chaps in the dedicated powertrain machine shop, a small room packed with tools to weld, cut and machine almost any component, often at short notice, using a mix of the ultra new and the traditional techniques that have served Jaguar engine development for many decades. Research by its very nature involves the unforeseen and as a team, their resourcefulness and creativity has saved many a day. It is the talents of dedicated people like this that form the ‘DNA’ of the company.

After initial assessment of the engines, it soon became clear that the naturally aspirated version would meet its performance targets with ease, something that is quite rare in the rest of the car industry, and the supercharged version could exceed expectations without effort so the original power target was raised from 500 to 510 bhp.

The first car I drove with a prototype engine, in 2007, was one of the first engineering ‘hacks’ and so the engine tune was still splendidly raw. It is from this point that skilled engineers start refining the car’s response, making the car do what the driver wants rather than just reacting to crude mechanical inputs. Before work could begin, this particular car had to be driven from Gaydon, where it had been assembled, to Whitley for testing. As I was making that journey myself I volunteered to take the test car, unfortunately it was pouring with rain and as yet there was no traction control – this lead to a few moments of unintentional entertainment and a degree of sideways progress, but even at that embryonic stage it was still a wonderful car to drive.

Indeed it is an essential part of the vehicle’s development to test drive in every type of likely environment so that the design can be finalised before test cars are sent for official emissions certification all over the world. So cars are out and about with disguise kits on years before launch, trying to avoid the hoards of press photographers camped out in the hedges near the factory. Whenever ‘spy shots’ of a new car are printed, it’s standard practice to work out who was driving and then mock them mercilessly, although sometimes it can land the driver in real trouble if more is revealed than is wise.

As ever, refinement is an essential Jaguar characteristic and this has been achieved by ensuring the moving parts are perfectly balanced in the traditional manner, but also with the new Gasoline Direct Injection (GDI) system, where the fuel is forced directly into the combustion chamber at very high pressure. It controls combustion in such a way as to minimise vibration and noise, effectively by shaping the way the cylinder pressure rises, as well as reducing emissions, better fuel economy and higher performance as if the system raises the fuels octane rating. The whole engine is designed round the system and a lot of hard work ensures all the different factors work in harmony, from the computer synchronised high pressure pumps to the crystal operated injectors that give a sequence of perfectly formed fuel pulses.

An experimental race vehicle recieves the new 5.0, light and strong with a tuning potential well above 600bhp.

 

The technology has near magical control, when you hit the start button the engine will synchronise, analyse the current air and coolant temperature, check the oil level and temperature, check all the sensors are working, set the fuel pressure on the twin double-acting high pressure pumps, check and adjust throttle angle, set all four cam positions, charge up the ignition coils and the 160 volt injector control circuit and be ready to fire the first cylinder within one revolution of the engine.

And it’s not just the engine that makes for a stunning drive; the gearbox is a lighter yet stronger version of the ZF 6 speed which works in a detailed and complex harmony with the engine, exchanging data and requests in a high speed electronic conference. For instance – when changing gear the gearbox asks the engine to adjust power to balance the kinetic energy left in the drive train and so removing any cause for a jolt or surge, it all happens in a fraction of a second, all for your driving pleasure.

It’s all very impressive stuff and a million miles away from the possibilities available nearly 20 years ago when the design of the last V8 started. The sheer volume of work that goes into the new engine merits a celebration: so for the privileged few of you who get to drive one of these wonderful cars, please take a moment to look under the bonnet, a lot has gone into that modest space.

Fault codes and conspiracy

I was hearing about some chap who ran his car on Biodiesel and had a few engine problems, the engine would loose power and display the legendary ‘Check Engine’ light prompting him to take it to a dealer to have the fault codes read. There were many fault codes set, mainly due to various blockages, which lead the dealer to change a number of expensive components that in truth were perfectly ok. His conclusion was that

The check engine light, lack of knowledge can lead to bad interpretation and expense.

manufacturers must design the fault detection system to generate revenue from needless parts sales, this is of course complete cobblers, not least because manufacturers always loose heavily when any part is changed under warranty. But also bear in mind that thousands of us Engineers work developing these systems and on the whole we are not a bunch of psychopathic con artists with a hatred of the driving public! On the contrary, most of us are car enthusiasts and obsessed with doing thing right.

So how did this bloke end up in that situation, and what strange sequence of events led him to his disparaging conclusion?

Well, Biodiesel made to BS 14214 contains a fairly high amount of solvents which can cause issues

in cars that have run on ordinary diesel for some time. Wax and other deposits can build up a bit like those fatty deposits you get inside dishwasher drains, but the solvents in biodiesel clean out the tank and fuel lines causing the debris to float off and block the fuel filter (which is only doing its job). Common practice when deciding to run on biodiesel is to fit a new filter first, run the car for a short time to flush things through and then fit another filter; they generally cost only a few pounds. But on this car that wasn’t done and the fuel flow became restricted so when the demand was high the engine would loose fuel pressure and reduce the power level to compensate, to the driver the car drove normally until accelerating hard to overtake when it would suddenly loose power.

Be careful what you put in the tank, cheap fuel can cause expensive repairs.

A fuel pressure fault would be flagged but international fault code listings are, by their very nature, quite generic which works well for most problems, but in this example the system would only be able to detect that the fuel system pressure had dropped as the demand increased when he was overtaking. As soon as the engine had been restarted the pressure would return.

Once the engine has been restarted a few times the system must assume the fault has been repaired, as there are big penalties for manufacturers if their cars keep flagging false warnings, and so by the time the diagnostics tool was plugged in the codes may have been cleared automatically. So when our chap went to the dealer there would be no trace of the fault code for de-rating, just some ones about fuel pressure which lead to the dealer mistakenly replacing the fuel pump at great expense which obviously would not cure the blocked filter. The customer took the car away and unsurprisingly the same problem occurred, so he took it back to the dealer.

In this case the dealer stated that as well as the generic codes there are manufacturer specific codes that can only be read by the manufacturers own diagnostic equipment, so the system was hiding information and it wasn’t their fault. This is unfortunately what started the conspiracy theory!

Manufactureres spen millions testing engines in all conditions to eradicate faults.

Manufacturer-specific fault codes are there as an extra layer of sophistication and reflect aspects of the engine system design that are unique to that manufacturer and that particular type of engine. They are even more open to misinterpretation which is why car companies are keen to only give them to people who have been properly trained. So yes; there is a separate fault list, but it’s not some secret conspiracy, just a reflection of the very high complexity of modern control systems.

It could well be that the garage personnel had difficulty understanding the diagnostics which is entirely understandable as the systems are hugely complex and every car is different. Not only that, but the technology is changing all the time, so having an understanding of common systems available five years ago is of very little use on cars of today. This complexity is driven by emissions legislation, safety requirements and customer demands whilst reducing costs, it is done out of necessity. Modern engine management is one of the most complex and demanding control systems commercially produced, and yet this feat is hardly recognised, which is a shame.

Its complicated enough without conspiracy theories.

So the moral of the story is two fold; there is a skill to interpreting fault codes and they need to be used in conjunction with traditional fault diagnostic techniques (ie: if there is not enough fuel getting through, check for blockages!), and manufacturers don’t design in faults deliberately, it’s hard enough as it is!

Mighty Midget

The man and his dream machine

Stuart Gunn did something remarkable; he set about creating this remarkable car in a remarkable way.

He sat down and thought about it, worked through the options, made templates and jigs and then went about welding it all together in a sensible logical well engineered way. Which is remarkable when the very idea of a V8 4×4 Midget is so splendidly mad.

The basic concept was to take the drive train (gearbox, props, diffs and hubs) off a Sierra XR4x4, take a Rover V8 3.5 with a good road tune, add in the MG Midget and blend with a home made chassis and subtle body mods. The result is a beautiful looking car that is easy to drive and blisteringly quick, particularly off the line where the extra traction from the four wheel drive gives it one hell of an edge.

With the power to scare small children...

Stuart learned his craft over the years with a number of projects, which all started off a couple of decades ago as a yoof with a Morris Oxford with a jacked up rear, a flip front and side exhaust pipes. By trade Stuart is a panel beater, which shows in the skill with which the steel wheel arches are seamlessly blended in to the MG body.

looking down on creation...

The build started with his mildly tuned Midget that he had driven round for a year or two. He then measured everything up and made suitable jigs for the wishbones and chassis out of steel box, so that the final result would be spot on and match on both sides.

The chassis uses the best bits of the original MG tub, added to a box section lower chassis and tubular upper rails which hold the top wishbones and coil over dampers on.

The 4×4 system uses the Sierra front diff and so Stuart created his own unique front cross member with the diff mounting on the right hand side (on the Sierra it mounts onto the sump).

Wishbone jigs held the bush carriers in the correct place, then steel tube was cut and welded in place to join them together, that way Stuart knew the geometry would be as predicted and both sides match.

Cunning front suspension

The suspension uprights have the struts removed and a ball joint fitted in there place, these parts came from the kit car manufacturer, MK Engineering. Being a tad narrower than a Sierra, the drive shafts had to be shortened, but not by too much, only 70mm.

Springing comes from coil over AVOs all round, with adjustable spring seats and damping. The first iteration saw 150lb springs on the rear but these ended up coil bound, now it has 225s which are spot on. Damping was adjusted to give good ride quality and handling, but also to stops the mud flaps dragging when going over speed bumps.

Wing and arches hint at the potential within.

Stopping the car is taken care of by Sierra based disk brakes with EBC Green stuff pads. As yet there is no servo, this is one possible mod for the future, but for now the braking is still excellent as long as you press the pedal firmly.

When it came to fiddling with the engine, Stuart had a chat with Dave Ellis of DJE fame. Stuart is working on a tight budget and isn’t after stupid horse power figures so a package was assembled to give the 3.5 litre about 200bhp and great drivability. It has a pair of 4.6 heads which have bigger ports and valves than the old 3.5 units and are not too expensive, a DJE 210 cam for good road manners, a Webber 500 4 barrel carb and Rover electronic ignition coupled to an Accel Super Coil. The carb breathes through a filter with a cleaver mod, because of the lack of space the top of the filter housing is the bonnet, a flexible mounting lets the filter seat even when the engine twists under acceleration. Though fuel injection is on the cards for a future mod.

Relatively light weight but torquey V8

Stuart made his own exhaust manifolds from tube and then Custom Chrome Racing very kindly chromed them and made the rest of the system. Stuart has known CCR for many years and so was allowed to use their workshop to do the fiddly bits. In fact CCR even provided the steel for the chassis and wishbones as well as making the oil catch tank. The resulting exhaust has that wonderful V8 burble but is not intrusively loud, quite subtle in fact, in keeping with the theme of the car. And all with just one small CCR muffler on each side.

Various wheel arches were tried by Stuart, including ones off a Transit double axle, but in the end he again made his own which complement the understated look perfectly. To make these he took a piece of small steel tube and bent it round the tyre, then he flattened the tube and braced it to the body with more bits of tube. This made a perfectly formed skeleton which he could then make up some cardboard arch templates and offer them up until he got the look that he wanted. Once satisfied with the templates he made steel arches and welded them on to the skeleton. The result is well made and has a factory quality feel to it as well as looking the dogs danglies.

Smoothed front give nothing away

The body was finished off by removing the bumpers, fitting a natty small bumper at the rear, adding a boot wing, a small bonnet bulge and smothering the thing an a gorgeous Rover Caribbean Blue paint job.

When designing the car Stuart wanted it to be usable every day, and on a short trip round town the car proved that this goal has been well and truly achieved. The suspension soaks up the bumps well and copes with speed bumps effortlessly. Once out on the open road the thrust from the engine is never ending, pushing you into the seat and putting a grin on your face. The Toyo Proxes tyres grip well and corners are dealt with easily.

A wonderful car to drive in any conditions.

At low speeds the steering is a little heavy, using a power steering rack to get the 2.8 turns lock to lock, but as yet without the power steering bit fitted due to the lack of space in the engine bay. Electric PAS is a possibility. But as the speed builds it becomes lighter and very communicative.

A lot going on in a small place, front suspension may recieve PAS later.

All in all, this is a simply splendid car, well thought out and professionally built. Stuart has plenty of ideas for future tweaks but the basics are very well sorted out. The car would be marvellous at hillclimbes and sprints and Stuart is toying with the idea of doing a few competitions in the coming year, I for one would love to see it out there.

As a footnote, how different would history be if BL had put something like this into production back in 1972….

Stuart would like to thank the following:

Graham and Nigel at Custom Chrome.

Dave Ellis at DJE

Many friends, family and Midget And Sprite Club members for their support and encouragement.

Tech Spec:

MG Midget Mk3 1972.

Rover V8, 3.5l, lightened and balanced flywheel, Vitesse pistons, 4.6 heads, DJE 210 cam, Webber 500 4 barrel, Rover Lucas ignition and Accel coil. Approx 200bhp @ 5500rpm.

Owner fabricated 4-1 tube exhaust manifolds with Custom Chrome Racing system.

Owner fabricated spine type chassis.

Owner fabricated double wishbones all round. Fully adjustable.

Ford Sierra Xr4x4 gearbox (type 9), props, diffs, hubs, steering and brakes. Narrowed by 70mm each side.

EBC greenstuff pads.

Toyo 195/45-16 Proxes tyres on Ace alloys.

Avo coil over adjustable dampers with adjustable spring seats all round.

0-60 4.5 seconds ish.

The Mugen Honda Civic Type R

The Mugen Honda Civic Type R has a very long name, it also has a very big rear spoiler which is attached to a very small car. Small cars with powerful engines are a tried and tested recipe for fun, thrills and teenagers driving into lampposts outside McDonald’s, in short it’s a winning formula so it seemed rude not to take up the offer of thrashing this icon of the Burberry clad yoof of the day. The location for said thrashing was the fantastically twisting snake of a road that is Millbrook’s Alpine route, yes that’s the one where they filmed James Bond rolling an Aston but as I am not being chased by super-villains I feel confident that the car will remain shiny side up. And that is quite important as there are only 20 of these UK models, although as always with ‘limited editions’ if popular there will surely be further runs of similar but not quite exactly the same models. Right, enough preamble, to the car:

More badges than a keen Scout.

Snug is a good word, even the word ‘snug’ feels snug, as do the Mugen’s seats. The interior is a bit like a condensed version of that corner of Halfords where all the hoodies gawp at excessively loud stereos, as well as the usual dash with the now obligatory ‘Start’ button there is an extra set of largely pointless gauges telling the driver things that most wont really understand in a sculpted pod. When I used to write for Max Power magazine I would see a lot of this sort of thing. But whilst it is very easy to mock, the remarkable thing is I rather like it, it appeals to the child within in much the same way that those enormous Lego Technic sets do, I feel that at my age I really shouldn’t but actually I really want to. As soon as the seat hugs me and I pull the red seatbelt down the whole car just screams to me ‘drive fast’, so not wishing to disappoint that’s what I proceed to do.
The superb two litre VTEC engine is quite audible but still reasonably civilised, it pulls away without drama and can be driven normally, although I have no idea why you would want to because as soon as it comes on cam at about 5500rpm there is a goodly surge of thrust and the engine starts screaming like an aged rock star on a come back tour; strong, purposeful, loud, tuneful with a rough edge, exciting even, but not necessarily something you would want to listen to at 6am on a damp Tuesday morning commute.
In low gears the 8600rpm rev limit arrives rapidly and a certain joy is to be had swiftly charging through each of the close ratio gears, the selector is wonderfully accurate and fast (I believe the trendy term is ‘snickerty’ or something, but that sounds like a word made up by people who cant describe things properly).
The exhaust noise is predominant but the intake makes a healthy roar too, when blasting through the gears the rasping and popping is terribly addictive urging me on to higher speeds just so I can change gear again. I actually found myself laughing out laud.

The Civic is a futuristic looking car anyway, maybe it should fly?

Turning into fast corners in the standard Civic results in the now traditional dull under-steer and a vagueness to the steering, the Mugen is a world apart and very direct, a lot of the compliance has been taken out and the geometry altered to suit the sportier driver with remarkable results. The turn in is so positive that I feel I could just will the car to go round corners, it responds quickly to every input from me and almost becomes an extension of my body. I say almost as it is not quite the same as a true race car, but there again this is a road car that can still accept a full load of shopping, it’s still hugely addictive and I soon find myself deliberately taking tighter lines round corners just to enjoy the joy ride.
Each corner follows the same format; brake late enjoying the powerful and responsive brakes, short shift a couple of gears enjoying the bark from the exhaust on overrun, throw an arm full of steering in and power out with the engine screaming round to the rev limiter, slicing through the roller coaster Millbrook track. Admit it, you want a go now don’t you!
For the first few minuets this car brought me sheer joy, I was laughing out loud. But after a while the fact that I had to keep constantly changing gear became a tinsy bit tedious, and the fat tyres tram-lining on the rougher bits of road surface required constant correction which started to become tiring.
And that’s it in a nutshell; the Mugen is huge fun, briefly. Not an everyday car, unless you are extremely addicted to go-karts and are slightly hyper active, in which case constantly flailing your limbs about to get the best out of the car will second nature.

Whats in a name? About 237bhp, actually.

Would I buy one? Probably not. But would I borrow a mates one? Oh yes, as long as I could get back from the race track before he finds out what I’d done with it!

Spec:
Weight 1247kg
Performance 6.0sec 0-62mph, 150mph, 30mpg
Length/width/height in mm 4280/1795/1440
Price £38599
Engine 1998cc 16v 4-cyl, 237bhp @ 8300rpm, 157lb ft @ 6250rpm
Six-speed manual, front-wheel drive

Subtle, unobtrusive, both words that seem lost near that wing.

Car faults in perspective: What can possibly go wrong….again..

One in a million.
My boss told me “so that means your design will defiantly kill two people per year!”.
That was 20 years ago, when I was a fresh faced engineering graduate in my first job at a global car maker. I was designing bits of engine management system, and as ever I had gone through every type of conceivable failure and worked out how well it was protected against. But one very obscure scenario involved the car stalling on a hypothetical level crossing near a strong radio transmitter, a bit tenuous but it is a situation that could happen, I had gone through the figures and worked out that it was a million to one chance that the engine would not restart, resulting in something bad involving a train and sudden localised distortion to the car (ok, a crash).
I thought that this was a remote chance, but my then boss pointed out that the systems would be put on about 2 million cars per year in Europe, hence his terminal conclusion.
I redesigned it. No one had to die.

Cars made in high volumes are used in every sort of environment possible, testing for all occurances is a huge investment.

But even so, I am sure there could be even more obscure situations I had never even thought of, I probably could have spent years going through more and more complex scenarios, but the the car would never have been made. So we have to draw the line somewhere.

How common are uncommon faults?
Cast your mind back to Toyota’s ‘sticky pedal’ problem, millions of cars work fine yet a handful of unverified complaints necessitated a total recall. You just can’t take chances, even if almost every car is perfect.
Of course Toyota are no worse than Ford, Mercedes and all the rest, all volume products suffer from occasional problems, largely due to the scale of production and of course because we want our complex cars dirt cheap, and that’s not going to change any time soon.
When an industry has to make very complicated machines with highly sophisticated features that are used by the general public who have only minimal training, and have to endure a vast array of harsh environments including salt spray, Arctic freeze, road shocks and days on end in scorching sun, things are going to be difficult. And when this problem is massively compounded by having to make the car as cheap as possible, something has to give.

New ideas like this Rolls Royce EV undergo a huge amount of testing before any customer is allowed near it.

Times this set of problems by the millions of cars made every year and the law of averages is definitely not on the side of car makers. If you think about it, the mere fact that when something does go wrong it makes the headlines tells us something about the utterly fantastic job that all these companies usually do.
If the average Joe knew anything of the vast amount of sheer hard work that goes into creating cheap, economical, useful and reliable cars they would bow down in reverence, and those that fancy their chances at suing for spurious accidents would hang their head in shame.
But hardly anyone knows about all that fantastic engineering work, it doesn’t make sexy TV programs, it’s not vacuous and glamorous enough to make it into the glossy magazines. So every one just accepts that every machine should work perfectly no matter what, and are utterly surprised on the very rare occasion that it doesn’t.
So how often do things fail? Well things are much more likely to go wrong when any product is either new or reaching the end of its designed life, the first few miles a car experiences show up any glitches in production and then once these are sorted most modern cars will trundle on for over a decade without significant problems (assuming its correctly maintained). During the cars early life car makers measure things in returns per thousand and generally they run well below 5, that’s 0.5% of cars having any sort of fault at all in the first year of ownership. Good models will run at less than 0.005%, and these faults could be anything from a cup holder breaking to an engine failing. The trouble is that if you churn out a couple of million cars a year then even these tiny numbers mean there will be hundreds of failures in the field, unfortunately these make good stories. Manufacturers hate even these small numbers of faults, obviously every company’s dream is to have no failures at all, and indeed some models achieve this, and they are all striving to eradicate all potential for failure. But occasionally I think its a bit sad you will never see a headline reading ‘millions of car turned out to be pretty good actually’.

Even a very high powered Porsche can be safely driven sideways in the rain by an idiot driver, as shown here.

Cars are amazing.
Here’s a challenge for you; think of a machine that has to work in heavy rain, baking sun, snow, ice, deserts, be precise on tarmac yet still cope with cobble stones, Suffer grit and gravel being blasted at it from underneath and do a huge range of complex mechanical tasks at temperatures between -40 to +50 C, last over a decade whilst being shaken, accelerated, decelerated by novice users in a crowded and complex environment.
There are no other machines, just motor vehicles, which have to contend with all this.
But it doesn’t stop there, the engine is retuned every combustion cycle, hundreds of times each second in order to meet the incredibly stringent emissions laws, pollutants are measured in parts per million, the tests are so sensitive that simply exhaling into an emissions test machine would cause the limits to be exceeded (note; these are not the simple emissions testers used at MOT stations, the MOT emissions limits are laughably lax by comparison to the certification tests the manufacturer has to do).
To give you a very rough idea of the amazing computing power needed to control and engine to these limits, a modern engine control box (ECU) may have around 25 thousand variables, tables, maps and functions. It calculates mathematical models of how the air flows through the intake system, how the pistons and valves heat up and how the catalysts is performing, it analyses the subtle acceleration and deceleration of the flywheel every time a cylinder fires, it listens to the noise the cylinder block makes and filters the sound to decide if the engine has the slightest amount of knock (in fact some engine deliberately run the engine into borderline detonation to extract maximum efficiency). It talks to the gearbox to anticipate gear changes and control torque so that the gearbox ECU can precisely control the energy input into the drive line during a gear shift. It analyses the long and short term behaviour of every single sensor and actuator to automatically compensate for ageing and wear as well as diagnosing and compensating for any faults.
But it doesn’t stop there, on some cars the suspension analyses the road and adapts to suit, the auto gearbox monitors the drivers ‘style’ and changes the way it works to please them. The brakes check wheel speed thousands of times a second and deduce when a tyre is about to skid, not when it already has started skidding, and relieve brake pressure just before it happens to ensure the tyre provides maximum grip and stability.
The climate control breathes in cabin air through tiny aspirated temperature sensors and adjusts valves and flaps to discretely meet your comfort needs. The stereo selects a nearby station as you drive along and seamlessly switches in so you never have to retune in order to continue to listen to Radio 2 on long journeys. All sorts of things are controlled and monitored from fuel pumps to light bulbs.

This is the engine and gearbox control from a 20 year old Jaguar, since then it has got a whole lot more complicated!

All in all an average family car might have between five and ten computers working together, sharing information and jointly controlling the car, a typical example would be the ABS unit supplying road speed info to the gearbox so it knows what gear to select. Luxury cars can have over 50 different computers, even the seat heaters have self diagnosing control brains in and talk to the car on a serial bus, and they all interact with things like the battery management systems which may at any time request all these systems change the way they are operating in order to cope with some adverse situation.
The way these systems work together can be very complex, for instance stability control uses the ABS system to apply brakes on individual wheels in order to pull the car to one side as well as requesting a certain wheel torque to ensure the car goes in the desired direction, this torque is controlled by the gearbox and engine working together too, the engine can react almost instantaneously by altering the spark angle (these events happen so fast that the engine has to wait for the airflow to reduce going into each cylinder even though it moves the throttle immediately, because of the air’s inertia!).
Components have to operate faultlessly for millions of cycles, if an engine or drive-line fault develops then the systems must identify it, adjust the mode of operation to minimise risk to car and people, and alert the driver, just like having an expert mechanic on board.
In addition the car has to be comfy by isolating key frequencies from being transmitted by the suspension and engine mounting systems, prevent wind noise from the gale force breeze rushing past the shell, stop the metal box that makes the cabin sounding like a metal box and muffle the many kilowatts of noise running through the exhaust pipe.
It also has to be economical, using every drop of fuel sparingly, compromising the shape of the car itself to reduce drag whilst still allowing enough space to get everything in and have enough air flow round the hot bits to stop them degrading.
But as well as being frugal it also has to perform well, even a modest family hatchback these days has the performance of a race car from the ’60s, indeed there are many saloons with well over 500bhp now, compare this with the 1983 F1 race winning Tyrrell with 530 bhp. Yes our super comfy mobile entertainment centres have the performance of an older Formula 1 car.
And not only does it have to balance all these driving related tasks but it also has to have a really good sound system and have most of the comforts of home, some even have cup holders and fridges.

A few decades ago an Engineer could just look at a car, such as this ultra rare Lagonda V12, and understand how it worked. How times have changed.

Not even the Space Shuttle has to contend with this level of sophistication. I can’t see rockets running catalytic converters and exhaust mufflers any day soon.
And here is the kicker; as well as coping with all that, it also has to perform special functions in a crash. We have multiple air bags, who’s operation is tuned to the ‘type’ of crash detected, we have automatic engine cut, hazard indication, seatbelt pre-tensioning and some cars even ring for help. The structure is designed and tested to ensure it collapses in a controlled manner, the engine design is constrained by pedestrian head impact tests on the bonnet, even the steering wheel is designed to steadfastly hold its position as the cars structure a few feet in front of it is crushed at a rate of up to 15 meters per second.
Name me one other machine that has to detect, reliably, when it is about to be destroyed and then deploy safety mechanisms in a controlled and measured manner during the actual process of its own destruction. You’ll struggle with that one.
Now this feat of engineering would be amazing even with an unlimited budget, but the fact is that cars are made as cheaply as possible, which just take the achievement from amazing to utterly astonishing. In fact you can buy a basic car for the price of a really good telly, that’s bonkers.

Please take a few moments to look at your own car, and marvel. And if one part goes wrong by all means take it back and get it fixed, but do try to be sympathetic to the scale of the problem engineers face.

The road ahead is challenging, but also very exciting as Engineers turn dreams into reality.

Post Script:

Media hype
I noticed something interesting during the Toyota recall, the media could have played a very useful role and helped society, I say ‘could have’ because what they actually did was the complete opposite.
What they could have done is reported actual news, facts presented objectively such as ‘a small numbers of cars may have a fault causing the pedal to be stiff’. That is a fact, it gets the info over simply and effectively, you know what is being said. Simple.
They could have gone further and said something like ‘if your pedal feels stiff visit your dealer, but first check the floor mat hasn’t got stuck under the pedal’. That would be helpful.
But they didn’t do that.
No, what actually got reported was along the lines of ‘mum of five in death plunge tragedy’ and ‘is your car a ticking time bomb of doom?’. Stupid, dramatised gossip that conveys absolutely no useful information.
But of course this scaremongering helps to boost sales of that form of media bilge, so expect more useless crap in the future about every important storey going.
And this is a real problem, not only because it leaves us all badly informed and scared, but because the car companies now know that being honest and open has become the wrong thing to do.
All media has a responsibility, and its time they (we) faced up to it.

Relying on the unreliable.

When I was little I remember listening to old people talking about a time when there where no cars, the feeling of excitement and wonder when they saw their first one rattling and belching down the cobbled street, a feeling mixed with a little fear as the mechanical marvel seemed to take over every aspect of life. Where once they played safely in the road, now the car was the king and a ruthless one at that. Communities divided by a constant steam of deadly traffic.
Of course today we take the car for granted. It would be an over simplification to say we have moved away from the workers slums into suburbia and now rely on the car to support this freedom, but you get the idea.
We teach our children ‘road sense’ so they can cross the road safely. Most drivers are not deadly speed demons (although in town most people still speed, 40 in a 30 zone IS deadly), everyone works together to make the new situation work. Society adjusts and we move on.
Now it seems that its my turn to sound old because I remember a time when there were no PCs.
I remember the excitement of my first Sinclair ZX80, and the awe of seeing the colour ZX Spectrum. In fact looking back I can still feel a little of that excitement about those pioneering machines.
But now I feel the fear, a deep and profound fear.
Now don’t get me wrong here, I am a great believer in the usefulness of computers, I have a degree in computer systems engineering, I have made a career out of devising computer control systems for cars and I love gadgets.
But still, now I feel the fear.
When I was studying to become and engineer, every step of the way I was told of the importance of doing things properly, especially where safety or security were concerned. With a large computer program we were taught to exactly and correctly specify what it should do in every detail. We had to also specify what it must not do! Once the program is written then it must be tested against this specification, and every possible combination of circumstances must be tested. That is the only way to ensure there are no ‘bugs’ and unexpected side effects.
But life is not like that, it turns out.
The software (and also hardware now) on almost everything is so complex that it requires a computer program just to be able to test it.
No one programmer can understand the whole thing, its just too big, so we have teams which may be spread out across the world. This gets complicated in itself so now we have programs to help the teams work together without bits getting left out and to prevent miss interpretations etc.
But we live in a market driven society. Its not usually the engineers alone that create products, it’s the corporations. Many individuals with their own beliefs on how things should be done dictating the boundaries and detail of what the engineers can do, but far too often without a sound understanding of the technicalities.
Money has too be made (although notable exceptions include Linux and shareware (three cheers)) and so whole chunks of code from other programs are grafted in to new programs, the people producing this new program may not know the details of how this chunk was written and all its effects. Sometimes there may be a ‘surprise’ effect caused by the interaction of this chunk with the rest of the program, or with other chunks grafted in or indeed other programs running on the same machine or network.
Testing takes time and money and delays the launch date. Some things just can’t be tested completely due to their nature, for example if your program predicts the weather then how do you test every possible combination of weather across the whole world and still meet the project deadlines.
The hardware too is so complex that it is not commercially viable, or indeed possible, to test every single thing. With several million transistors on a single chip it is never going to get tested for the effects of every combination of individual transistor failures.
So that’s where we are today. Our systems are only partially tested and often a patchwork of other peoples work all stuck together with what boils down to little more than hope and optimism. Or indeed sometimes cynicism if the corporation concerned has little respect for the end user of its products.
Many consumer products are made by inexperienced teams and pushed out by unscrupulous corporations (particularly in countries where software standards are not enforced) and are largely unproven. There is also the modern phenomena of social networks, these are a great benefit to individuals and businesses alike and I use Twitter, Facebook, Google+ and blog sites to generate interest in my work. In fact I rely on these systems as a key part of my business, but these were never even designed to be mission critical business tools.
Many of us have experienced the result of this growing problem, such as the PC just locking up when you try a new program or simply getting slower and slower as time goes by. These bug and software faults are so common that many people think it is normal for computers to behave like this. It must be realised that it doesn’t have to be this way technically, but commercial pressures could continue to make the problem worse.
Complexity is a big problem and is the subject of many a professor’s career.
Now, the reason that I am writing this is not just to have a good grumble about my computer crashing or indeed to complain about commercial forces ruining good engineering. Those thing make me angry, but they are not the cause of my fear.
The fear stems from how we are using these systems as a society, how we are relying on the unreliable.
Computer systems are now increasingly being used as part of the law enforcement system, finance control, travel systems and even food production
Speed cameras always cause a good argument so I will stir things up a bit further. Now I know very well that excessive speed increases danger of injury and general twisting of machinery and limb, and putting a speed camera outside a school is no bad thing.
The issue for me comes from the fact that the picture generates an automatic fine for a person. There is no human judgement in the loop, bang, guilty until proven innocent. And that’s wrong.
A friend of mine suffered from a theft from his car, not from inside but from outside. The number plates were stolen. Persons of criminal persuasion had stolen a car, then went cruising round till they find an identical type of car to put an innocent chaps plates on their stolen car. Then they can generate speeding fines and parking tickets with impunity and even commit serious crime knowing full well that the system will point the finger at some one else. It even causes the police to waste time with the wrong chap during the investigation, keeping the heat of the criminals long enough for them to make their escape.
Guilty until proven innocent, not good, not very British.
Soon we may all have ID cards. This means that criminals only need to forge one item instead of a string of items as at present, thus making their life easier. Another classic case of the decision makers not understanding the technology.
The systems used for security on such cards are simply to complex to be testable, and driven down on price so the quality has to suffer. It’s simply not reliable.
If you want quality you have to pay for it because quality systems take more time to engineer, and crucially more time and resources to test, it all costs money.
In the near future there may be an attempt to make remote vehicle arrestors mandatory on all new cars. This system uses ABS systems that have full authority breaking and engine management systems to bring a car to a halt using a radio command that only police will have.
In a simplistic world this is great, you report your car stolen and the police can bring it to a halt when the conditions are safe. No more getaway cars. Well, unless criminals use older cars, but that loophole is easily solved by making classic cars illegal and crushing them all!
The problems include accidental stopping of the car (you cant prove the software completely due to its complexity and you cant prove the hardware completely because you cant test every failure and every type of possible radio interference etc), incorrect use by the police or other agencies, vehicle being stopped by criminals equipped with illicit stopping systems for the purpose of car jacking. Finally there is always a way to bypass the system, always a loop hole, a bug, a back door or an ‘unintentional feature’.
I was on a train in Germany a while back which suddenly stopped in the middle of nowhere without warning, brakes full on. Luckily I had finished my coffee so the cup was empty when it flew off the table. The cause of this potentially dangerous emergency stop was a software error in the very system that is supposed to protect the train from crashes.
Our corporate based society does not allow for well written systems to be made as profitably as quickly written ones.
This is a real problem, and it is getting worse as more systems are used which interact with each other in even more complex ways.
In my life I rely on a mobile phone, I rely on my car, my computer, email, bank direct debits, automatic payments, alarm clock, microwave, fridge, washing machine etc.
The power feeding my home is controlled by systems all linked together in a network across the country and even linked in to grids in other countries. Some years ago a large areas of the USA lost power as one network was hit by lightning which knocked out a power station, the systems automatically switched in power from other networks but this overloaded them, a domino effect then ensued as one grid after another went out.
Even the basic things in life are computer controlled, like the amount of chlorine in the water I drink. And to be fair most of the time all these systems do a fantastic job, but can we rely on it?
Aeroplanes are flown expertly by computers over my head, the air traffic is controlled by other computers. These systems have traditionally been tested to the highest standards and the track record is superb. But of course it is still a commercial enterprise, and as fuel prices creep ever upward there is increasing pressure on the technology to deliver more for less cost.
I use my switch card to pay for car tax, the little computer in the post office reads my details and talks to one of many networked computers at the bank, the figure in my account file is reduced and a message sent to the post office bank computer to tell it to increase the number in it’s account. Then a message is sent to a computer at DVLA and it changes the value of a variable in a file so that when another program does it’s daily check of who has tax it will not automatically send a message to another computer to send me a fine and automatically turn me into a criminal. I never see these computers and they never see me. But they can bankrupt me accidentally or send me to jail.
At the large scale these systems are not designed by engineers, they are created by politicians and sales executives who simply don’t understand every detail of the system.
When I was a child, I was proud to be British, a country that believed in tolerance, understanding and fair play. I was proud of my country.
Now I am scared of my country and the automatic systems that rule my life.
My bank local branch has just got rid of all its cashiers, you have to use the machines now. Signatures are being replaced with PINs.
These systems give us great ability as a society and as in individual, but if we are to rely on systems then they must be reliable. Particularly government systems and essential services must be run to the best standards we can think of.
Also, there must always be a human in the loop when ever civil liberty is at stake. This is fundamental to a fair and just society, we must have the right to explain and contest. After all it’s not like we are short of people in the world to help out.
And finally, there must always be a manual back up for those odd days when things don’t quite work the way they should, just in case.

The most powerful piston engine in the world

Big is good, it’s official.
As you hopefully know, power is generated in our car engines by burning fuel. The heat makes the pressure go up which pushes the piston down just like you foot bearing down on a bicycle pedal. It’s a nice simple theory. The trouble is that most of the heat released into the cylinder is wasted, at full throttle about a third goes into the coolant and the other third goes down the exhaust pipe. At part throttle its even worse, up to 90% of the heat is wasted. A small fraction of the exhaust energy can be recovered with a turbo but basically it’s very wasteful.
So how can we improve things? Well, to retain more of the heat energy in the exhaust we can reduce engine speed, allowing longer for the heat to be used. But how can we reduce the heat absorbed by the cylinder wall? We could use some funky materials like ceramic but that has its own problems.

An engine, look carefully in the middle there is a bloke on the third floor! (Picture - WÄRTSILÄ)

However, one fundamental scaling rule applies to all things in the universe, if you double the volume of something, the surface area only increases by about 1.4. This is good for engines because a smaller proportion of the heat is lost to the cylinder walls. It’s not so good for creatures that breathe through their skin, like spiders which can never get much bigger than your hand without collapsing in a heap.
So why not use massive engines everywhere? Of course the efficiency bonus of big engines only applies at high loads, at part throttle the massive cooling effect of a high surface area ruins the fuel economy, so in the car world we size an engine to be appropriate for the job the car is supposed to do. For instance, when cruising down the motorway most cars only need about 18 bhp, so building a small engine that has peak efficiency at that power would be great for that single job, and indeed that is what the ‘mileage marathon’ cars do, but of course there is nothing left in reserve for accelerating, so we go for something closer to a 100bhp engine in a smallish car.
But what about something bigger? The biggest vehicles produced are ships, and in particular supertankers which can be the length of a drag race track.
So the subject our adoration is the mighty Wärtsilä-Sulzer RT-flex96-C, in particular the 14 cylinder version. Its total cylinder capacity is 25480 litres, I’ll just let that sink in for a moment.
It is a two stroke diesel engine with four, very large, turbos and computer controlled poppet type exhaust valves. It gobs out 84.4Mw which is 114800 bhp at only 102 rpm, and as you probably know torque is power divided by speed, that equates to about 6 million lb/ft of torque. Which is a lot.
Fuel economy is brilliant at full load – amazingly only 171 grams of fuel per kWh, ok that might not mean too much to most people but it is about twice as good as a diesel car. But if you drop the load to 85% and best efficiency the consumption is only 163g/kWh, which with the fuel containing 42.7 Mj/kg relates to about 51.7% efficiency. But this is not the best efficiency in the piston world, I think that is the Man S80ME-C7, catchy names.

Now that's a big crank, you should see the ballencing machine! (Picture - WÄRTSILÄ)

Everything about it is big in a whole new way; each cylinder is 960mm (37.8 inches) bore by 2500mm (98.4 inches) stroke, giving 1820 litres per pot. At full tilt, 102 rpm that is, a mean piston speed of 8.5 meters per second and the average pressure in the cylinder (MEP) is about 20 times higher than atmospheric which all means that each individual cylinder produces over 7700 bhp (the same as a top fuel drag race car) whilst consuming about 160 grams of heavy smelly fuel oil each stroke.
The outside is even more impressive, they call this type of thing a ‘cathedral engine’. At nearly 14 metres tall, 28 metres long it has four stories of walk ways round it. And weighing in at 2300 tonnes its not going to fit in a car!
Even the fuel pump is impressive, it looks like a huge V8 designed by Dr Frankenstein and delivers up to 1660 gallons per hour of heated fuel oil at 1000 bar to the common rail diesel injection system. Each cylinder has three injectors which are operated independently to control the combustion flow, the way the flame moves around the chamber, resulting in no smoke even at full load. The fuel control allows the engine to run over a wider range of speeds than older generation engines, indeed on the 12 cylinder version they managed to get it to run at only 7 rpm experimentally, that’s one ‘kaboom’ every 9 seconds, which is very slow.
It uses, more or less, the usual two stroke block scavenge intake system, that’s where the underside of the piston compresses the air. But that’s as far as normality goes, here it is refined with one way valves the size of tea trays and then the air hits four very impressive turbos, each the size of a small garden shed, before going through inter-coolers the size of Portacabins and entering the cylinder via a port near its lower edge. For starting, massive electric blowers pump in air at about 30 bar.
The exhaust poppet valves are fully computer controlled, a servo uses oil at 200 bar to move the valve up and down, so the cam profile exists only as software in the virtual world of the control box and is totally variable. The exhaust valve opening is reduced at part load to keep the exhaust temperature above 150 ºC to prevent tons of sulphur from the unrefined fuel corroding the exhaust after treatment system.
The pistons are mounted solidly onto an upper con rod, called a piston rod, that has a joint at the bottom that runs in guide rails, to keep the piston rod upright all the time. It’s called a cross head and ensures that the piston has no side loading and the oil control is tight enough to give the engine a 30 year service life, and most of the time in all those years the engine will be running flat out, which is pretty amazing. The lower end of this rod connects to the con rod proper and then on to the crank, the main bearing caps have ladders on them for the service crew to walk up.
Did I mention it’s quite big?
These engines are used in container ships like the Emma Maersk, about 170 thousand tons of it which is propelled at up to 26knots and is assisted by no less than five 8000 bhp Caterpillar engines just for helping with manoeuvring.
It’s got quite a big propeller too.