Tractor Vaporising Oil
From a Political Perspective

 

Imagine (or remember) yourself in Post War England. Shipping had been decimated during the preceding violence and all oil came from abroad. So did much of the much-needed food that was people ate. Folk had barely clapped eyes on so much as a banana for years. Demand for “luxury” foodstuffs was intense. The English people had fought hard and won, but still they had no means with which to buy imported goods.

 

The nation was in debt up to its eyeballs! If it wasn’t grown locally, it cost a bomb. Somehow the debt incurred in fighting the war against Hitler had to be re-paid. Indeed, as a child of the 50’s I clearly remember being brought up in a country where coal fires were the norm for middle income to well off families, paraffin was the fuel of choice for factory workers’ families and anyone with a supply of wood would use that as a cheaper alternative for household heating, cooking, etc. A refrigerator was a luxury (unlike in America), a Bulter sink was the norm and there was a draught under every door, which rushed straight up the nearest chimney. Those who had carpet did not have it wall-wall. For the most part, precious, luxury items had to be imported using shipping, which no longer existed. Our industry was desperately struggling to manufacture the real basics of life. We had a complete infrastructure to rebuild. Water supplies, electricity power stations, gas works and roads all needed to be re-built following the devastation of the bombings. Tens of thousands of the men who would have performed this re-building had been killed in the fighting. Immigration was being begged for, to replace lost manpower. Every penny that could be collected in taxes was put towards repayment of war-debt and rebuilding costs. We were living to a standard, which today, we would consider to be like Third World poverty.

 

It is with this background in mind that we are considering a Post War Government determined to glean as much tax as humanly possible, especially on imported products to subsidise re-construction of infrastructure and shipping. Petrol, therefore, was a prime target and farmers, simply couldn’t afford to pay the tax. We are all hearing daily, today, that farmers are desperate in their attempts to keep costs in line with prices. Things were much the similar in Post War England; even to the extent that if The Authorities decided that a farmer was farming inefficiently, he could have his land confiscated. The surviving people were in real need of good quality food, and lots of it. Government were subsidising farmers to grow cheap food. Government were also controlling food prices as far as they could. Where was the farmer to get the money to pay the tax on the petrol to run his tractor to grow the food for which there was such desperate need? There was certainly a much-reduced labour supply – most of the labourers having been killed at war. Farming, therefore HAD to be mechanised and cheap petrol-engined tractors were, ideally, the way to go, were it not for the tax on petrol.

 

 

 

 

 

 

 

A brief history of the technical origins of the fuel

 

Tractor Vaporising Oil was being produced at a time in English history when very many people used Paraffin as a home heating and cooking fuel. The way that paraffin was made, was to start with what we now know of as standard 28 second Heating Oil (kerosene) and then strip out the aromatics.

 

In the simplest terms, the aromatics are the smelly bits, which contain the highest Octane rating and lowest flash point of any part of the fuel. We’ll come to Octane presently. The point here is that for indoor, home use, neither smell nor inclinations for the fumes to explode are particularly desirable qualities in a household heating fuel.

 

With many millions of gallons of paraffin being made each year, there was a whole load of these aromatics left over. So what did they do? They added these aromatics to more kerosene, thus creating kerosene with a higher concentration of aromatics and, therefore, a higher Octane value and lower flash-point. In short, the resulting fuel was something cheap and fairly safe, between heating oil and petrol, but without the Road Fuel Duty.

 

Compression Ratios

 

The Compression Ratio of an engine relates to the comparison between the amount of space above the piston when it is in it’s lowest position and the amount of space above the piston when it is in its highest position.  When a fuel-air mixture is compressed in this way, it is inclined to rise in temperature. This, in turn, improves the inclination of the mixture to explode, or burn. This heat is derived from the energy consumed in compressing the mixture and, on the one hand,  represents a small, but significant loss in the Internal Combustion Engine, but on the other hand imparts a greater efficiency to the “burn” thus rendering the machine more efficient overall.

 

To take the thing to it’s, inevitable, conclusion, a fuel can, in some cases, become so hot under compression that it ignites spontaneously. This is the principle discovered and applied by that nice Mr. Diesel when he invented his Diesel engine. The problem, however, with the Diesel engine, is that the pressures are extreme and have to be accommodated in the structure and mass (and technology) of the engine. Therefore, in general terms, a Diesel engine is heavier and slower to accelerate than a Spark Ignition engine of the same power. Thus, mankind has endlessly sought a compromise in his search for a form of power with which to feed his insatiable need for cheap food and goods.

 

So, to sum up! We need a compression ratio, which will be low enough to avoid Compression Ignition and high enough to encourage Spark Ignition.

 

Carburetion

 

A carburettor is not much more than a puddle of fuel across which a draught of air is blown (or sucked). That air picks up a (metered) quantity of fuel from the puddle (a bit like the way the wind whips spray off the cap of a rolling wave at sea). Obviously there are a number of variations on this principle, but that is the basic key to it.

 

The Tractor Vaporising Oil carburettor on a Ferguson tractor is different to that of a petrol Ferguson tractor. There is an extra drilling (which is virtually undetectable) across the bottom of the bowl, behind a pair of tiny lead plugs. The only way to tell that the carburettor is a Tractor Vaporising Oil model is that it is marked VO. Small as this difference may sound, it is important as it allows a small proportion of extra fuel to be delivered.

 

Manifolds

 

The next, and very important element for burning Tractor Vaporising Oil is the manifold of the engine. In a petrol engine, there is a small, but very significant amount of heat transfer between the exhaust and inlet channels. With a Tractor Vaporising Oil engine, that heat transfer has to be greatly increased. The heat vaporises the fuel to a fine mist, thus delivering it to the combustion chamber is a more readily flammable state. There have been a number of different manifolds made to “convert” Ferguson tractors to Tractor Vaporising Oil, two of which were made by the Loddon Engineering Vaporising Company locally to us, here in Norfolk.

 

Other examples include the Fishliegh manifold:-

 

Ferguson, in due course, made their own Tractor Vaporising Oil manifold as fitted to the TE D 20 and other Vaporising Oil and Lamp Oil models:-

 

Background

 

Back to basics.

Q.       Why did Mr Ferguson want his tractors run on Tractor Vaporising Oil?

A.       He did not!

 

Mr Ferguson developed his Perfect tractor, the TE A 20 to run on petrol. These tractors had a plentiful sufficiency of power and were light on their feet, which meant that they did not damage the soil.

 

Q.       So why was the Ferguson TE D 20 introduced?

A.       Mr. Ferguson, on behalf of farmers the nation over, tried to persuade the Government of the time to allow for a tax-free petrol (which had been withdrawn during the war) to power tractors providing food for a hungry post-war nation. Government, as we so often find to this day, were intransigent. Petrol, being derived from oil, was hard to come-by, post war. It all had to be imported from abroad. Shipping had taken a terrible hammering in the hostilities and as a nation we were desperately poor by today’s standards. No tax-free petrol became available after the 2^nd World War.

 

Farmers clamoured for a tax-free fuel and pressed Mr. Ferguson to produce a tractor, which would run on red Diesel for lack of tax-free petrol. Mr. Ferguson was firmly against this course of events. He had spent years perfecting his tractor and was not about to willingly enter into re-engineering it, unless it was unavoidable. Diesel engines in those days were, by their nature, heavy, slow-running and dirty. They were also far less reliable than petrol engines.

 

Messrs. Perkins converted a large number of Ferguson tractors with their engines, persuading farmers that they would save money in the long run with tax-free fuel. We will probably never know if these early Diesel conversion ever paid for themselves. I have my doubts.

 

What we do know is that Mr. Ferguson was furious! Having expended so much time and energy getting the geometry of his tractor exactly correct, he considered that the Perkins Engine Conversion utterly despoiled his design.  I am convinced that he was absolutely correct. As a result, work was undertaken to develop an engine, which would run on a tax-free fuel and the Ferguson TE D 20 was born. This retained the original Standard Engine at about the same weight, but with modifications.

 

The Tractor Vaporising Oil on which the new model was to run was of such a low Octane that the modified engine had to have a compression ratio of only 4.5:1 if it were to avoid serious ‘pinking’. That necessitated a re-design to the cylinder head. This, in turn, reduced performance very considerably. That was why it was bored out to 85mm to compensate for the power loss. It is worth noting at this point that very many farmers still bought the TE A 20’s and, indeed, TE A 20 ‘s made up over half the 517,651 TE 20 series tractors, ever built. The main point was that the TE D 20 had the same basic geometry as the TE A 20, Mr. Ferguson’s Perfect Tractor. The engine was no heavier and the power output as the same.

 

According to the experts at Shell Technical:-

 

Tractor Vaporising Oil – Recommendations for an alternative fuel

Although Tractor Vaporizing Oil (TVO) was withdrawn in 1974 a number of TVO engined tractors still exist. These are operated by such organisations as Cricket Clubs, Vehicle Preservation Societies etc., and we are often asked to recommend alternatives to TVO. The purpose of this Bulletin is to provide a background to the subject and our suggestions for a suitable substitute.

Standard grade kerosene is obtained from crude oil as a fraction with a boiling range of about 150/250°C. Because it did not attract a high duty like petrol, kerosene became established a long time ago as an engine fuel, usually being used in spark ignition engines with exhaust/inlet manifold heat exchangers to vaporise the fuel and having low compression ratios to suit the low octane number of about 15/20. Paraffinic crudes were most suitable for wick-type burners in lamps and heaters because of their lower tendency to smoke but, as engine fuel they were of lower octane number. Conversely, naphthenic and especially aromatic crudes had lower burning and smoke qualities but were better engine fuels as they had a higher octane number.

Premier grade burning oil was developed from the standard grade by using extraction processes to remove a large proportion of the aromatic content. The burning quality improved but engine performance deteriorated as the octane number fell towards zero.

Tractor vaporising oil came into being as an improved kerosene for engine applications by blending into standard grade the high octane aromatics which had been stripped from premium grade burning oil. By this means TVO acquired an octane number in the order of 55/70.

In describing these products and their octane ratings, no mention is made of determination by research or motor methods. At the levels of octane qualities involved, there would be little difference.

From the point of view of distillation characteristics and ease of vaporising in the inlet manifold, there is nothing to choose between TVO and standard grade kerosene. However, the octane quality of the latter fuel is lower and caution must be exercised when using standard grade kerosene to avoid knock. Vile therefore suggest that the following procedure be adopted by our customers:

As the first step, try running the engine on standard grade kerosene. If knock, which is readily audible, is encountered stop the engine and add about 10% Shell Optimax to the tank. Repeat this trial, adding Optimax in 10% increments until knock disappears and the engine runs smoothly. The petrol content of the mixture should never exceed 50% and there are distinct advantages in keeping this proportion to a minimal level. The lower the petrol content the lower the cost, and the lower the fire hazard. Unleaded rather than leaded petrol is recommended since exhaust valves in TVO engines are not necessarily lead resistant.

We would emphasise that when making up blends of fuel, the proper safety precautions must be observed. The most practical and safe way is to pour the two components into the machine fuel tank and leave the natural turbulence of filling to complete the mixing. It is also suggested that users check with their insurers in case any modification to insurance policies is required. A kerosene/petrol mixture is almost certainly more hazardous than the individual components and it is for this reason that safe handling must be stressed. Standard grade kerosene does not carry road excise duty and blends with gasoline should not, therefore, be used on the road without Customs & Excise sanction.

OECW/0 October 2003

 

 

 

 

 

Octane

 

 

Q.              What is Octane?

A.       Octane is a measurement of the dis-inclination of a fuel to ignite by compression. The higher the Octane rating, the less inclined a fuel is to “Diesel”. Other words describing this are “Pinking”, “Detonation”, “Pre-Ignition”.

 

 

Q.       What Octane rating are we looking in Petrol?

A.       About 98 Octane

 

 

Q.       What Octane is standard kerosene?

A.       About 15 – 20 Octane

 

 

Q.       What Octane is paraffin?

A.       Zero – because all the aromatics have been stripped out.

 

 

Q.       What Octane is Diesel fuel?

A.       Since the very thing we want Diesel fuel to do is compression-ignite, Diesel fuel has an Octane rating of Zero.

 

Q.       What will happen to my Tractor Vaporising Oil engine if the Octane rating is too low?

A.       The compression ignition fire, which occurs on top of the pistons will   damage them.

 

Q.       What Octane reading are we looking for in a Tractor Vaporising Oil tractor?

A.       For a Ferguson tractor, you are looking for an Octane rating somewhere between 55 and 70

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Some pictures showing “Pinking”

 

It’s quite important to think of the fire inside a cylinder more of a burn than an explosion. The ‘burn’ is not an instantaneous thing. It takes time and should ‘chase’ the piston down the bore, and aught to go out before it catches the piston at the bottom.

 

 

As a result of this Pinking, the ‘burn time’ is wrong, power output is poor, pistons become damaged by the fire on their crowns, Compression Ignition may even take place prior to T.D.C., and the whole thing is altogether undesirable.

 

 

 

 

 

So what is wrong with the fuel if I am getting pinking?

 

We have seen “recipes” for Tractor Vaporising Oil everywhere we look which recommend the use of Diesel, 2 –stroke oil and all sorts of hydrocarbons, which are zero Octane. These recipes are nothing short of wasteful of financial resources and plain bad for your engines.

 

Think of it like this:-

 

Your base fuel (most of these recipes) is Kerosene (28 second Heating oil). That’s a perfect start. It’s Octane rating is above zero and below that of the end result; and it’s cheap – more or less tax free.

 

We know from what we have seen above, that we need to RAISE the Octane. Petrol is a perfect fuel to use to do this. It’s readily available (if a bit expensive) and it has a high Octane rating. There is no longer a supply of the aromatics retrieved in the manufacture of paraffin, so why not stick with good old-fashioned petrol?

 

Then these recipes suggest the addition of Diesel fuel. Why? All that will do is to reduce the Octane rating nearer to zero. The more Diesel you put in, the lower the Octane. No benefit there then!

 

Some recipes suggest adding 2-Stoke oil.

 

Why?

 

These oils all have an octane rating of zero. What could the benefit possibly be?  Aha! I hear you say. Upper cylinder lubricant!

 

Why?

 

The reply I keep hearing is “reduces the chances of piston seizure”.

We are not using Tractor Vaporising Oil in a 2 stroke engine! These engines start and run perfectly well on petrol with no upper cylinder lubricant at all. Why would we need upper cylinder lubricant?

 

A half-pound of butter!

Well, not so daft as some of the other suggestions. It’s a perfectly good hydrocarbon and there is always benefit from humour!

 

 

 

 

 

 

 

 

 

 

 

I know I’ve trodden on a few corns here

and most sincerely apologise.

 

 

If I were not so certain that I’m right, I promise I would not have done it. The fact is that there have been people before us who’s opinion we, rightly, respect and who were correct about almost everything else they taught us, but on this they were just plain wrong and we believed them. Now we have gone out there and proselytised their faulty beliefs in our own good names and embarrassed ourselves. I did the same and had to own up that I had been led astray.

 

 

 

What happens if we use fuel

with an Octane value which is too low?

 

We have already mentioned that the pistons will be damaged if there is “Pinking”. The same applied to valves. In particular the exhaust valves may experience damage.

 

 

 

Running too cold

 

Those things mentioned above are almost secondary to the problems caused by thinning of the sump (lubricating) oil by running your Tractor Vaporising Oil engine at temperatures lower than those for which it was designed. Liquid fuel will run down the cylinder walls and wash them of any carbon and oil and it will all land up in the sump, thus thinning your lubricant till it will not lubricate any more, ever again. This will have obvious detrimental effect on your engine and cost a fortune in oil changes..

 

The whole point of the Petrol-Start function is that Tractor Vaporising Oil will not burn right if it is not hot enough. Indeed, it will not burn at all if it is cold. Work your engine hard if you are on Tractor Vaporising Oil, or turn back on to petrol. Ferguson Vaporising Oil tractors are intended to run on petrol if they are not running hard. The tractor Instruction Book states quite clearly that they should be run on petrol “for light work”. Frankly, a road run, for a tractor, is light work. Our old friends, at Vapourmatic, made a screen to cover your radiator, ‘when on light work’- so that the engine would run hotter. That’s all very well till you forget to remove it or roll it down when ploughing and:- Whoops! Overheated engine!

 

There is a better way:-

We supply Tractor Vaporising Oil at our works in Stalham. We always ask our customers to what use they intend to put their tractor on the fuel we sell. If the answer is Road Runs, we sell a mix with more petrol. If the answer is Ploughing, we sell a mix with less petrol. Tractor Vaporising Oil from us is £2.30 per gallon for ploughing or for road runs. That’s because we try to average out the costs and share them equally regardless of the particular application.

 

To Sum Up

 

When running on Tractor Vaporising Oil, keep your engine hot.

If you are not running hot enough, work your engine harder, add more petrol to your mix or switch over to petrol.

 

Don’t EVER use anything of Zero Octane in your Tractor Vaporising Oil recipe. It’s pointless, and expensive.

 

If your spark plugs are sooting-up, either increase the airflow or decrease your fuel at the Main Jet. Pay very special attention to your Air Cleaner. It MUST always be clean, and in the case of a Ferguson tractor, should be changed daily and, in poor conditions, twice daily. The cooks and chefs here will appreciate this bit! When the air is drawn through the oil it deposits little air bubbles in the oil. This makes the oil turn to a kind of mousse, which is thick and severely restricts the flow of air. The refrigeration engineers amongst us will appreciate that reducing air flow will, inevitably, induce freezing around the carburettor. This is very bad indeed, especially if there is water kicking around inside. It will freeze and block the fuel-ways. Alternatively, for carboned-up spark plugs, reduce your fuel input. Because you are using the correct fuel, it is not caused by excess oil, unless your engine is shot and oil is coming up from the sump. Old engines do need regular de-cokes as specified in your manuals. That is normal.

 

Change your engine oil regularly.

All modern engine oils are of far better quality than the old “Straight” oils. They maintain their lubricating qualities across a wider range of temperature and last longer. But they will not stand dilution with fuels any more than the old ones. If you have a Vaporising Oil engine, you risk dilution when the thing is not running at maximum power and temperature! The more often you change your oil, the less often you’ll change your pistons, rings and liners, rocker shafts and cam shaft bushes. Give the old thing regular oil changes.

 

I know I’ve banged on about Ferguson tractors a lot in this talk, but it’s only because that’s what we know about at Holland-Brand. Exactly the same principles apply to all other makes of Tractor Vaporising Oil engine.

 

Some of you might have paraffin engines. Some of you will have Tractor Vaporising Oil engines, which you refer to as petrol - paraffin. This term “petrol – paraffin” is often a misnomer. How it developed I cannot judge. Many of you here, tonight, are experts in the field of your own particular type of engine. Those experts will know if you are running Zero Octane engines designed to run on paraffin or not. Apart from anything else, paraffin is dearer than 28 second Heating Oil. So, if you have a Tractor Vaporising Oil engine, run it on Tractor Vaporising Oil.  If you have a Ferguson TE H 20, TE J 20, TE M 20 or TE S 20, you have a tractor, which was, designed to be, “exported to hotter climates” and run paraffin fuel. That would be very unusual in England and it will probably run better on Kerosene or Tractor Vaporising Oil in the UK (especially in winter). You should, also, change the needle valve in your carburettor for one designed for a Tractor Vaporising Oil model unless you are running it very hot on paraffin in summer.

 

 

The law

 

A friend of ours has had this letter from H.M.C.E:-