Answer:
1) The adoption of the second design we can see that the total valve perimeter is increased by 60.8%
2) Increase in flow are : 29%
3) Additional benefits in using 4 valves per cylinder:
a)For the purpose of controlling the combustion process, the inlet valves will give more flexibility
b) There is a larger valve throat areas for the flow of gas
Explanation:
1) Perimeter of the first possible overhead valve combustion chamber with two valves:
P₂ = πd = π × 23 = 72.26mm
Perimeter of the second possible overhead valve combustion chamber with four valves:
P₄ = π2d = π × 18.5 × 2 = 116.24 mm
If second design is adopted, percentage increase = ((P₄ - P₂)/P₂)×100
= ((116.24 - 72.26)/72.26)×100 = 0.6086 ×100 = 60.86%
Therefore, the total valve perimeter is shown to have increased by 60.8%
2) Formula for flow Area (A) = P × L = πkd²
Area of the first possible overhead valve combustion chamber with two valves: A₂ = πkd² = πk(23)² = 1662k mm²
Area of the first possible overhead valve combustion chamber with four valves: A₄ = πkd² = 2πk(18.5)² = 2150k mm²
The percentage increase in flow area: ((A₄ - A₂)/A₄)×100 = ((2150 - 1662)/2150)×100 = 29%
3) The additional benefits of using are:
a) For the purpose of controlling the combustion process, the inlet valves will give more flexibility
b) There is a larger valve throat areas for the flow of gas
