Many cast iron pistons are designed with heat dams, which serve to （）
1、Trunk-type diesel engine pistons are m
Trunk-type diesel engine pistons are most effectively cooled by heat（）Aconducted through the engine blockBconducted to water cooled cylinder wallsCconducted through the piston crownDloss to escaping exhaust gase
2、The pistons are cooled by oil supplied
The pistons are cooled by oil supplied from the forced （） system.Afresh waterBsea waterClubricationDfuel oil
3、Trunk type diesel engine pistons are e
Trunk type diesel engine pistons are effectively cooled when heat is（）Aradiated through the engine blockBtransferred to water cooled cylinder wallsCconducted through the piston crownDtransferred to escaping exhaust gase
4、The piston rings are manufactured with
The piston rings are manufactured with a diameter （） the bore of the cylinder.Alarger thanBsmaller thanCequal toDnone of the above
5、Piston cooling fins are located（）
Piston cooling fins are located（）Aatop the piston crownBbeneath the piston crownCat the base of the piston skirtDinside the cylinder liner cooling water jacket
6、These piston rings are so badly worn t
These piston rings are so badly worn that they must be （）.ArenewedBweldedCmachinedDchromium-plated