6.5 An engine manufacturer has decided to change one of its engines from a spark ignition...

6.5 An engine manufacturer has decided to change one of its engines from a spark ignition type to a compression ignition type. If the swept volume is unchanged, what effect will the change have on:

(i) maximum torque?

(ii) maximum power?

(iii) the speed at which maximum power occurs?

(iv) economy of operation?

Solutions

Expert Solution

(i) Maximum torque will decrease . This is beacuse the swept volume is not changed, so the diesel will not get enough compression in order to burn properly and the heat produced will be less. So enough torque will not be generated.

(ii) As Power = 2πNT/60

So the product of torque and speed will decide whether the power has increased or not. Now as the torque is already decreased so the maximum power will also decrease.

(iii) Converting SI to CI will reduce the speed at which maximum power will occur.

(iv) Overall economy of operation will decrease as the efficiency of fuel is highly reduced due to incomplete combustion.

samet mamat answered 1 year ago

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