The Horsepower Chain –
Racing Engines Optimized Through Hardcore Math
The 4 stroke internal combustion engine first ran in 1876. This engine design, known as the Otto cycle, has been thought of as having the following strokes – intake, compression, expansion and exhaust. This design is used in the vast majority of racing engines today. Engine builders, and racers alike, think about improving the performance of their engines using this 4 stroke approach, or what I prefer to call the “old 4 process.”
Sometimes people focus on the 4 critical camshaft timing events – intake valve opening (IVO), exhaust valve closing (EVC), intake valve closing (IVC), and exhaust valve opening (EVO) to characterize engine performance. This was a good step forward, but a finer breakdown is needed to really understand racing engines.
Instead of the traditional 4 strokes, the modern high performance engine should be thought of as having 7 distinct individual processes. This “7 process” approach focuses on air flow through the engine and is a result of two decades of research while developing the worlds most popular racing engine software — Quarter Jr’s “Engine Pro”
The New 7 Process Model:
These 7 processes are linked together and affect each other in turn. In other words, the output from one process defines the input for the next. It follows logically that each of these 7 processes must be fully optimized in order to achieve the highest engine performance possible.
However, the overall engine is only as good as the weakest link in this chain of processes. Some changes may well improve one process, but hurt another. Identifying which of these 7 processes is holding the engine back is key to improving your engine’s performance.
The physics behind each of these 7 processes is very different. All we can adjust/change is the shape of the components that make up the engine. What is the absolute best combination of components? How do we find that best combination without just throwing parts at the engine?
Announcing: “The Horsepower Chain – Racing engines explained through hardcore math”
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