Part 1: Thermal coating
Thermal coating aims at keeping heat in the chambers that would otherwise dissipate into the water jackets of the engine. This improves the overall efficiency of power strokes. This thermal coating is applied to the pistons, chambers and valve heads.
The compression ratio of the Chevy 302 engine is switched to 13 and the effect of thermal coatings is plotted below. The increase of power and torque per cc can be interpreted easily from the figure.
Part 2: Bore-stroke ratio
The bore-stroke ratio is the diameter of the cylinder bore is divided by the length of the piston stroke. A square engine has equal bore and stroke dimensions. For example, Nissan's SR20DE is a square engine.
An oversquare engine allows the use of large valves in the head of the cylinder that contributes higher possible rpm and intakes more air-fuel mixture. It favors top speed at red zone. However, the large piston and head surface area causes significant amount of heat loss. An undersquare engine increases engine friction and actuates stress on the crankshaft. A smaller bore is usually followed by a smaller valve that lowers the amount of air-fuel mixture during internal combustion. It favors peak torque at lower rpm with low heat loss and the fuel economy is guaranteed. However, a longer stroke accomplishes a longer angular cycle so that the performance is not desirable to use in engine circuit.
Part 3: Compression ratio and the total number of cylinders
A higher compression ratio allows a stronger power stroke because the explosive space is smaller. If more cylinders are installed in the engine, more power will be produced. It's the chamber where the gasoline is burned and turned into power. Generally, an engine with more cylinders gives more power. In contrast, an engine with fewer cylinders gets better fuel economy.
Part 4: Piston force
The chemical combustion undergoes more vigorously in a larger compression ratio. That's mean the piston force should be varied by the compression ratio. In the Chevy 302 engine, the piston force is not linearly proportional to the compression ratio. The piston force increases in a slower rate when the compression ratio (CR) is higher than 11 but it is natural in terms of statistical mechanics.
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| unclealsautorepair |
Thermal coating aims at keeping heat in the chambers that would otherwise dissipate into the water jackets of the engine. This improves the overall efficiency of power strokes. This thermal coating is applied to the pistons, chambers and valve heads.
The compression ratio of the Chevy 302 engine is switched to 13 and the effect of thermal coatings is plotted below. The increase of power and torque per cc can be interpreted easily from the figure.
Part 2: Bore-stroke ratio
The bore-stroke ratio is the diameter of the cylinder bore is divided by the length of the piston stroke. A square engine has equal bore and stroke dimensions. For example, Nissan's SR20DE is a square engine.
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| wk |
An oversquare engine allows the use of large valves in the head of the cylinder that contributes higher possible rpm and intakes more air-fuel mixture. It favors top speed at red zone. However, the large piston and head surface area causes significant amount of heat loss. An undersquare engine increases engine friction and actuates stress on the crankshaft. A smaller bore is usually followed by a smaller valve that lowers the amount of air-fuel mixture during internal combustion. It favors peak torque at lower rpm with low heat loss and the fuel economy is guaranteed. However, a longer stroke accomplishes a longer angular cycle so that the performance is not desirable to use in engine circuit.
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| Measurement data |
Part 3: Compression ratio and the total number of cylinders
A higher compression ratio allows a stronger power stroke because the explosive space is smaller. If more cylinders are installed in the engine, more power will be produced. It's the chamber where the gasoline is burned and turned into power. Generally, an engine with more cylinders gives more power. In contrast, an engine with fewer cylinders gets better fuel economy.
 |
| Measurement data |
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| Measurement data |
Part 4: Piston force
The chemical combustion undergoes more vigorously in a larger compression ratio. That's mean the piston force should be varied by the compression ratio. In the Chevy 302 engine, the piston force is not linearly proportional to the compression ratio. The piston force increases in a slower rate when the compression ratio (CR) is higher than 11 but it is natural in terms of statistical mechanics.
 |
| Measurement data |