My view on Alternative Fuels

There has been much talk of alternative fuels to keep our classics going as petrol becomes ever less attractive. But after all is said and done, more has been said than done.
Here is a brief summary of my experience and some hearsay from down the pub, it is quite possible I have made a mistake here or there so if you spot one do let me know.

LPG.

Here I've drilled into the intake manifold and I'm fitting LPG injector nozzles to one of our Rover V8s.
Here I’ve drilled into the intake manifold and I’m fitting LPG injector nozzles to one of our Rover V8s.


Mostly Propane with a splash of Butane, stored as a liquid under a pressure of about 5 bar in steel cylinders. The fuel is turned into a gas and the pressure regulated in an evaporator that is heated by engine coolant. The simplest way of feeding the gas into the engine is by using a gas carburettor, but these are quite restrictive and so peak power is significantly reduced, maybe by 20%, although most drivers don’t notice this for some reason. Often these systems are set up to run very rich to mask installation problems. Better way is to use gas injectors, similar to petrol injectors, with their own ecu, this is more expensive but more efficient.
LPG is usually less than half the price of petrol per litre, and although the fuel consumption on gas is slightly worse there is still an overall saving. A well set up system will have lower HC and CO emissions than petrol, but the higher fuel consumption leads to similar CO2 levels.
LPG has a higher octane rating and so engines can be redesigned with higher compression ratio to achieve higher power and economy, but again that is expensive.
As LPG is a dry fuel there can be issues with valve seats wearing, but only if the engine is worked hard. Special lubrication systems are available but many have problems with uneven distribution between the cylinders.
LPG supply is directly related to oil supply, so if petrol runs out then so does LPG.

Methane / CNG.
This is the same gas as you get in your domestic cooker, Compressed Natural Gas. On cars it is stored in very high pressure cylinders. You can get domestic pumps to fill the car from a household supply. The regulator and engine conversion equipment s similar to LPG, but with different flow rates. Again there is a power loss, slightly greater than LPG but not horrific.
Also the valve wear issues are similar to LPG.

Methanol.
An alcohol fuel with a fairly low energy content, so less power than petrol in a standard engine, but the high octane rating means that add a turbo or supercharger and you can have a very powerful unit. But if you’re happy with the power loss on a standard engine then home brewed methanol could be a cheap alternative to petrol. Unfortunately it’s very hydroscopic so cant be stored for long periods.

Ethanol.
An alcohol fuel with a fairly high energy content and octane rating, it makes a small gain in power on standard engines but can make even better gains on a modified engine with higher compression ratio or a blower.
It is very hydroscopic so has a limited tank life, it also has an unfortunate tendency to react with steel creating an acid that corrodes pretty much everything. So stainless or plastic fuel pipes, tanks and fittings are helpful. The exhaust is also corrosive so stainless systems are best.
Alcohol fuels can be brewed in much the same way as moonshine, using food waste, but getting the water out is very difficult.
Flow rate is much higher than petrol, so the fuelling system has to be modified to suit, although some conversions have managed to use standard injectors and fuel pumps.

Hydrogen.
It has no carbon and the only emission is water. Unfortunately its very difficult to store, requiring cryogenic tanks. As it is the smallest atom it tends to leak through pretty much anything, including steel. I
t also needs either very high pressure tanks or cryogenic (-253.7 ºC) liquid storage. The other problem is that its energy density is quite poor, so you need a lot of it. If it is injected into the port it displaces quite a lot of air, so power is significantly reduced. But of course this could be tackled by using a bigger engine or turbos, yes its true, with hydrogen you can have a guilt free 8 litre V8! British company ITM Power have developed a home hydrogen generator, simply add water and plug it into the mains, to prove its usefulness they converted a Focus which gets about 100 miles per fill.
And Sunderland university have used CNG (compressed natural gas, mostly methane) equipment, which is similar to an LPG conversion, with a special tank to run a standard car on Hydrogen. 
Again it’s a dry fuel so valve seat erosion can be a problem if worked hard.

Biodiesel.
Another brewed fuel, usually made from oily seeds or waste cooking oil. Quite expensive to produce on anything other than large scale industrial quantities. ‘Phase 2’ biodiesel is made from farm waste (husks and stalks left over from food production) and is more expensive but does not use up the worlds food supply.
Performs just the same as regular diesel as long as it is filtered properly. Because of the greater solvent content it will loosen any old fuel deposits from an old cars fuel system, which can clog filters and injectors, so its best to fit a new fuel filter then run biodiesel briefly before changing the filter again.
Being an organic substance it is prone to stuff growing in it, so it has a limited tank life.

Chip oil.
Some people run older diesels on filtered chip oil, there are lots of microscopic plant particles in this which carbon up the injector tip and can coke up the engine. The harder the engine works the worse the problem gets. Using modern diesel can wash some of the deposits away, so alternating fuels can extend service life. Modern diesels use much finer tolerances in the injection system and are a lot less tolerant of this type of fuel, but old fashioned mechanical diesel injection systems don’t seem to mind so much.

Electric.
Throw the engine away and fit a milk float motor? It has been done, in fact I did it to a Fiat X1/9 but that’s another story, but you have the performance of a milk float and the batteries are very heavy and take up a lot of space.
However, recently the century of pitiful investment has come to an end and the technology is finally getting proper funding. We now have electric sports cars, and even a few supercars. So over the next few years expect to see much more viable electric drive systems and batteries.
Personally I would love to develop a replacement electric system in the shape of an engine, I think that would be rather fun.

Advanced fuels from petrol stations.
Things like BP Ultimate and Shell V Power are formulated to coat the cylinder in a low friction coating, improve oil control and disperse more effectively to improve flame efficiency.
This does actually work, an engine improves over time with use as the coating builds.
The fuels cost more which can negate the economy benefit, depending on the engine and how much difference the fuel makes on that particular design.

Fuel supplements>

Hydrogen in petrol.
Mixing about 3% by volume hydrogen in the intake air can allow a petrol engine to run very lean, in this condition it is possible to gain 25% in efficiency. Maximum power will be reduced due to the displaced air, and the hydrogen requirement is quite large so generating it by an on-board electrolysis system is not usually viable. Also the engine change to make use of the lean burn potential is significantly expensive.
Introducing hydrogen without running the engine lean makes no improvement.
Using a jam jar of water and 12v electrodes is just plain silly.
A variation on this theme is to use thermal and catalytic cracking on the petrol to turn it into hydrogen and CO2, with engine modifications this can improve efficiency by up to 30% at part load. But its a very expensive system and complicated to control.

LPG in diesel.
Can improve efficiency by up to 20% but makes an even more dramatic improvement to performance. Over doing it will melt the engine, much like nitrous oxide on a petrol engine.
Cheaper than a conventional LPG conversion, this works very well indeed if set up properly.

One alternative, but not a good one...
One alternative, but not a good one…

 

The following things really don’t work.

Magnets, they have no effect on fuel what so ever.

Solid fuel ‘catalysts’, I have tested a few and none made any difference.

Air flow vortex or turbulators, these usually have absolutely no effect, although they do block the intake and turbulent air reduces flow rates, so they can actually reduce performance. Cars with mass air flow meters require extremely non turbulent flow, and usually have flow straighteners built in, turbulent flow creates false readings and may make the engine run slightly rich

Anything involving running your car on water.

 

The truth about electric cars

Or at least the truth from an engineering perspective. And that is an important distinction because of course the main catalyst for the change is political, there may be some very fine environmental and technical reasons for the change too, but politics holds all the aces. It can make oil prices prohibitive, it can subsidise new technologies that herald breakthrough innovations.
You see, every life changing new technology had to start somewhere, it usually starts off prohibitively expensive and a bit unreliable. Just think about those early mobile phones the size of a suitcase with a battery life of only a few minuets and call costs a hundred times greater than a normal land line. Or even the first computers, the size of a large room and less brains than a digital watch. The format is well established; pour loads of funding into research, laugh at boffins making experimental machines with questionable ability, wait for a company to spot the potential, get it into production and within ten years every competitor is developing better versions.

Rolls Royce are leading the charge (pardon the pun) in ultra luxury electric vehicles.

But electric cars are a bit of an exception because at the dawn of motoring they were a front runner, even Porche’s first car was electric. 130 years ago petrol was not readily available, you bought it in cans for quite a lot of money, car journeys were very short and cars were so expensive that only those with a large estate could afford one. Electric cars had the advantage over those first fledgling petrol cars in many ways, they were faster, quieter, much more reliable and had no starting problems. They didn’t even need a gearbox or clutch mechanism, so driving them was a far simpler affair than a crash box piston powered chariot.
But the materials technology needed to advance battery design was simply not there, the early EV hit a performance limit that it couldn’t break free from. The second problem was in motor control, all they had was switches, and as motors became more powerful the need for fine control at low speed became more problematic.
By comparison funding poured into petrol engine design, at that time it was far easier to improve than electric cars and oil companies were understandably keen to see this new product thrive. A couple of world wars forced engine design ahead very rapidly, not least to power aircraft from the humble Tiger Moth to the magnificent Spitfire.
Very rapidly it became far easier to make a high power, low cost petrol engine, opening up the possibility of cheap mass market motor cars.
Electric vehicles didn’t stand a chance. Half a century ago there was simply no reason to invest in electric vehicle research, emissions concerns had not yet manifested, climate change was unheard of and oil supplies were plentiful. A few enthusiasts continued to attempt to make electric vehicles, enjoying their simplicity and quietness, but materials technology would still limit their capability.
But times change, and now with political difficulties in oil supply, a far greater and ever developing understanding of emissions problems and climate change, coupled with massive advancements in technology there is an overwhelming desire to find alternatives to petrol and diesel.
This means that funding is now pouring into research in electric vehicles. But as mentioned above this is merely the first stage in a product becoming a commercial success, early adopters such as Honda with the Insight and more recently Toyota with the Prius have been suffering the commercial pain of subsidising less than ideal technology, but remember this is another essential stage in a technology’s development.
I hope that gives you an idea of where we are; about half way to getting a really useful, cheap and effective electric vehicle. There is now sufficient funding from a sufficiently large range of institutions, governments and corporations that the rest of the development process is pretty much inevitable, after all they all want to see a return on their investments.
Of course electric cars are not the only option for reducing CO2, existing piston engines could be re-engineered to run on hydrogen, and that fuel could be obtained by electrolysis of water. Storing hydrogen is a bit tricky unfortunately, but there are some exciting new developments that could make it a viable option. This has the advantage of using existing engine technology, but introduces large inefficiencies due to the process of hydrogen manufacture, its transport and the low efficiency of the internal combustion engine. You’d be lucky to turn 15% of the electrical energy used in hydrogen production into energy at the car’s wheels. and as ever you loose all that energy as soon as you apply the brakes.
The observant amongst you will know that lost energy from braking could be recovered by hooking up generators to the wheels and using the recovered energy to power the wheels on the next acceleration, as in KERS and other regenerative brake systems, but then you are carrying part of the weight and financial burden of the electric car but without all the benefit.
When you consider the total path from the source to the wheel the electric car can work out significantly better, potentially getting 50% of the source energy to the car wheels.
The other interesting possibility is gaining some, or possibly all, of the electricity from solar cells built into the car body. Various companies are developing composite body panels and special paints that act as solar panels that can be unobtrusively incorporated into the car design. In the UK the average energy from the sun through our legendary gloomy cloud is enough to power a small family car for about ten miles each day, so if all the car does is the school run and weekly shop then there could potentially be no fuel cost. Although as ever with new technology the first cars to have this feature will be hideously expensive and totally negate this benefit, but in time it will become a viable option.
Emissions are not the only reason for going electric, as the technology matures and becomes cheaper it will eventually become far cheaper to make an electric car than a combustion engined one. On a modern small car the engine and associated emissions systems can easily cost more than the rest of the entire car, getting this cost down is a huge incentive to car companies that struggle to make a profit at the best of times. in fact car companies have been trying to get up into electric cars for decades, remember the Ford Think?
There are many other benefits too, electric drives lend themselves to the ever increasing demands of advanced traction and stability control systems. As driver aids such as auto parking gradually evolve into fully autonomous self driving cars, having a simple method of accurately controlling the torque at each wheel becomes increasingly important.
When you put all these factors together the case for electric vehicles becomes compelling, and when you add in the political desire to reduce dependence on unstable oil producing countries the argument becomes overwhelming.
Obviously we are not quite there yet, historically the big problem has always been the battery. Old methods resulted in heavy, expensive and physically large units with limited range, they haven’t really changed in over a century. But in the last ten years or so there has been renewed investment, finally, and whilst there is still a long way to go we are definitely on the road to success already.
In fact as the ‘power density’ of batteries improves, eventually it will exceed that of petrol. This means that eventually electric cars will be lighter for the same power when compared to a petrol or diesel car, or more interesting to a racer like me, an electric car will be more powerful for the same weight. Imagine massively powerful electric supercars with precise control of the torque at each wheel from its four wheel motors, the ultimate in performance. The future world of electric vehicles is a very exciting place.
So there it is, electric cars offer huge benefits to the environment, car companies, drivers and world politics. They are not perfect yet, but within a decade or two they will be as ubiquitous as mobile phones.
And yes, before you ask, I still prefer the sound of a V8. But as long as the car accelerates as if it had one then maybe I could cope, after all we can always simulate the sound!

For more news about electric cars why not follow Robert Llewellyn, a superb ambassador for the EV revolution:bobbyllew

And you must follow Jonny Smith and his fabulous drag racing electric car ‘Flux Capacitor’: Carpervert