Question 135Motor Plants - Assistant Engineer

The correct answer is A) increased compression ratio. Inserting shims between the foot of a marine-type connecting rod and the bearing box would increase the distance between the piston and the cylinder head, effectively increasing the compression ratio of the engine. This is because the shims raise the position of the piston in the cylinder, reducing the volume of the combustion chamber and leading to a higher compression ratio. The other options are incorrect because decreasing the bearing clearance (D) would not affect the compression ratio, and decreasing (B) or increasing (C) the bearing clearance would not directly impact the compression ratio.