For many people the world of mechanical engineering is based upon the challenge to change and improve systems of years gone by. The two-stroke and four-stroke engine perfectly illustrates an inability of some people and some
companies to even consider there may be better designs out there. The Bourke Engine was created by a man called Russell Bourke in the 1920s. At the time he was simply looking to improve the widely adapted two-stroke engine. However, he came up with a system which was revolutionary and both challenging to large corporate entities.
History shows that the onset of World War II, a lack of credible results and the poor health of his wife prevented further development of the engine at the time. Fortunately, many people believed in the system, the changes and the very different mechanics of the Bourke Engine. Even today there are websites and leading mechanical engineers pushing for further research and incorporation of the two-stroke and the four-stroke Bourke Engine into the modern world.
What makes the Bourke Engine so different?
There are many aspects to consider when looking at the Bourke Engine but perhaps the most impressive is the fact that the two-stroke prototype, a full working prototype, only had two moving parts. This ensured that this new style of engine could be lightweight, powerful, double the power pulses per revolution and confine to the mechanical engineering dustbin many previously held beliefs.
Horizontally opposed pistons
The modern day internal combustion engine has been around for the centuries in some shape or form. While accepted as the “norm” it has significant inefficiencies not to mention the general wear and tear of the pistons and other components. Using a scotch yoke mechanism the Bourke Engine eliminates this damaging friction with the horizontally opposed pistons moving in the same direction – so they are always 180° out of phase. The scotch yoke mechanism replaces the crankshaft mechanism used today ensuring that piston acceleration is perfectly sinusoidal.
The incoming fuel charge is compressed in a chamber located under each piston although the connecting rod seal prevents the fuel from contaminating the lubricating oil. It is also worth noting that due to the increased time spent with the pistons at “top dead center” the fuel is burnt more efficiently. In a world demanding greater efficiencies, why has the Bourke Engine not received more interest?
This non-mixing of oil and fuel is vital to the efficiency of this system because the fuel is injected directly into the air as the pistons move – while ensuring that the lubricating oil for the central mechanism remains uncontaminated. It is also worth noting that once the system has “warmed up” the fuel is auto ignited with the air/fuel mix burning due to the high temperatures of the compressed gas. After the initial spark needed to start the Bourke Engine there is no requirement for spark plugs or other ignition components. Initially tests were carried out on over 2000 hours of constant use which confirmed that the oil remained pure and the components of the Bourke Engine showed no wear and tear (friction is a major problem with the modern day internal combustion engine). Is this a reason why there appear to be so many barriers to entry for the Bourke Engine?
Additional claims made about the Bourke Engine
A number of additional claims have been made about the Bourke Engine over the years which include:-
- A higher horsepower to weight ratio
- The ability to run on low quality fuel
- 35 hp or more at 5000 RPM
- Significantly less fuel required per horsepower hour
- Ability to run using multi-fuels such as natural gas, propane with many other fuels yet untested
- Negligible harmful emissions
- No fuel wastage via the exhaust pipe
- Significantly lower gas temperatures in the exhaust
- Compression ratios from 8:1 up to 20:1
- Fuel-air ratio 30:1 up to 50:1
Benefits of the Bourke Engine
The above list of claims made in relation to the Bourke Engine has resulted in the following theoretical benefits:-
- Highly efficient fuel combustion
- Very low fuel consumption
- Ability to use low grade (cheaper) fuel
- No emission control devices required
- Extremely low maintenance
- High HP to weight ratio
- No oil change required (oil is never contaminated by fuel)
Since the Bourke Engine was created there have been rumours, counter rumours, claims and counter claims with many people suggesting those with a vested interest are looking to muddy the water. The fact is that back in the 1920s a working model was created which did everything the inventor claimed. In a world where protection of the environment is becoming more important, natural fuels less available and more expensive not to mention greater efficiency sought in the world of automobiles, i.e. electric vehicles, surely it is time to revisit the Bourke Engine?
Companies, governments and investors are willing to spend literally billions of dollars on hybrid cars for example when tests show that the Bourke Engine would be perfect for power generators, hybrid cars, boats and light aircraft to name just a few of the endless possibilities. Is there a conspiracy? Why do the critics continue to suggest problems with the Bourke Engine while unable to provide definitive proof?
Why isn’t the Bourke Engine used?
Sometimes, just because a mechanical system has been used for centuries, we automatically assume it cannot be improved or even replaced. The internal combustion engine is known to have great inefficiencies but in reality it served a purpose and has done for many years. There has been some interest in the Bourke Engine from automobile companies but so far very little in the way of actual progress (paying lip service only?). The fact that the patent on the Bourke Engine has expired is also likely to be a factor in the relative increase in interest.
When you consider this engine has minimal friction, the main cause of component damage, the introduction of the Bourke Engine could decimate the engine parts industry. We all know this is a major income stream for automobile companies amid suggestions we are looking at a similar situation to when the electric car first emerged and was suddenly withdrawn. Many cars we see today make minimal profit for manufacturers at point of sale with the greatest income streams coming further down the line with servicing of vehicles and replacement parts.
Turkeys would never vote for Christmas so why would the automobile industry push an engine which would decimate their lucrative income streams?