Question

What is the compression ratio of an engine whose dimensions are 100*120 mm and length of clearance space at the top dead centre being 8 mm?

(a) 16:1

(b) 32:1

(c) 1:16

(d) 1:32

I have been asked this question in my homework.

The doubt is from I.C Engine in section Internal Combustion Engine of Farm Machinery

Answer 1

The correct option is (a) 16:1

Explanation: Total length of cylinder L = 12+0.8=12.8 cm

Height of clearance space = 0.8 cm

Clearance volume= area * height = \(\frac{π}{4}\)*10^2*0.8

= 62.8 cm^3

Total volume = \(\frac{π}{4}\)*D^2*L

= \(\frac{π}{4}\)*10^2*12.8 = 1004.8 cm^3

Compression ratio = \(\frac{Total \, volume}{Clearance \, volume}\)

= \(\frac{1004.8}{62.8}\) = 16/1

= 16:1