Compression Ratio Measuring Techniques

Why ignition curve is influenced by the type of fuel?
- The amount of compression ratio (Static Compression Ratio / SCR) determine the type of fuel that will be used in order to withstand the pressures of high compression
- The higher the SCR, the fuel used should have a higher octane anyway.
- The fuel has a higher octane fuel then it will be more difficult to burn.
- Difficult burning means requires a longer time for the propagation of combustion in the combustion chamber.
With the basic formula:
Compression Ratio (SCR) is the volume of the combustion chamber / (volume + combustion chamber volume of the cylinder)

Easy Steps to Determine Compression Ratio:
1 Prepare a measuring cup (burette) to measure the volume
2 Make the engine as in the position of the image under

3 Place the position of the piston at top dead center (TDC)
4 Fill the liquid gas + oil into the combustion chamber through the spark plug hole to the limit.
The results = Volume of Space Fuel (V1)
Measure the total volume (Space Fuel and Cylinder):
5. After step 4, immediately placed in the position of the piston bottom dead center (BDC)
6 Add the liquid contents had to limit the spark plug hole.
The results = Volume Total (Vtotal)
7 Calculate the compression ratio using the basic formula.
example:
From the measurement results obtained the following results:
- Space Fuel Volume = 9 cc (step 4)
- The total volume = 124 cc (step 6)
Thus, the compression ratio is:
V1: Vtotal = 9: 124
= 1: 13.8 (all divided by 9)
The result: Compression Ratio = 1: 13.8
Fuel used should be at least 100 octane MON namely: Avgas