Nissan patrol engine comp. ratio

[Toha]

I just saw in Nissan patrol engine specification .

Comp. ratio of

TB42 : 8.3.1
TB42e: 8.5.1
td42 : 22.7.1
So can anyone telll me plz .. what is comp ratio ...and which 1 is the better comp. ratio of above 3 thanks

[nissannewby]

Its the compression ratio of the cylinder. The top 2 are petrols hence why they are lower and have spark ignition. The td 42 is a diesel and therefore is a compression ignition engine as air heats up as it compressed thus causing the diesel to ignite.In a piston engine it is the ratio between the volume of the cylinder and combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke

[Toha]

thanks patrol guru

Its the compression ratio of the cylinder. The top 2 are petrols hence why they are lower and have spark ignition. The td 42 is a diesel and therefore is a compression ignition engine as air heats up as it compressed thus causing the diesel to ignite.In a piston engine it is the ratio between the volume of the cylinder and combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke