This document provides formulas for calculating engine cylinder capacity, cylinder volume, and compression ratio. It also gives examples of calculations for two Mitsubishi engines - a 4D31 with a 100mm bore, 105mm stroke, and four cylinders, and a 4D65 diesel with a 91.1mm bore, 95mm stroke, and four cylinders. Compression ratio is defined as the total cylinder volume plus combustion chamber volume divided by just the combustion chamber volume. An example is also given for a Land Rover diesel engine.

3. h
d
Cylinder Capacity = 𝜋𝑟2
× ℎ

4. 𝑐𝑦𝑙𝑖𝑛𝑑𝑒𝑟 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑦 = 𝜋 × (𝐵𝑜𝑟𝑒/2)2 × 𝑠𝑡𝑟𝑜𝑘𝑒

5. EX :-
01 Mitsubishi 4D31 Engine
Cylinder Bore = 100mm
Stroke = 105mm
02 Mitsubishi 4D65 Diesel Engine
Cylinder Bore = 91.1mm
Stroke = 95mm

7. Engine Capacity = 𝜋 × (𝐵𝑜𝑟𝑒/2)2
× Stroke × Number Of Cylinders

8. EX :-
01 Mitsubishi 4D31 Engine
Cylinder Bore = 100mm
Stroke = 105mm
Number Of Cylinders = 04
02 Mitsubishi 4D65 Diesel Engine
Cylinder Bore = 91.1mm
Stroke = 95mm
Number Of Cylinders = 04

10. 𝑣𝑐
𝑣𝑠
𝑣𝑐 - combustion chamber volume
𝑣𝑠 - cylinder volume

11. Compression Ratio =
𝑣 𝑐 + 𝑣 𝑠
𝑣 𝑐
Compression Ratio =
𝐂𝐨𝐦𝐛𝐮𝐬𝐭𝐢𝐨𝐧 𝐜𝐡𝐚𝐦𝐛𝐞𝐫 𝐯𝐨𝐥𝐮𝐦𝐞+𝐂𝐲𝐥𝐢𝐧𝐝𝐞𝐫 𝐕𝐨𝐥𝐮𝐦𝐞
𝐂𝐨𝐦𝐛𝐮𝐬𝐭𝐢𝐨𝐧 𝐂𝐡𝐚𝐦𝐛𝐞𝐫 𝐕𝐨𝐥𝐮𝐦𝐞
COMPRESSION
RATIO

12. EX :-
01 Mitsubishi 4D31 Engine
Cylinder Bore = 100mm
Stroke = 105mm
Combustion Chamber Volume = 50cm3
02 Land Rover (Defender 300T Di) Diesel Engine
Cylinder Bore = 90.47mm
Stroke = 97mm
Combustion Chamber Volume = 33.72cm3
COMPRESSION RATIO