Figure 2.31 shows a section through a typica! cylinder liner from a large two-stroke low-speed engine. Modern liners are manufactured from good quality alloyed cast iron and must satisfy the conflicting requirements of being thick and strong enough to withstand the high pressures and temperatures that occur during combustion and thin enough to allow good heat transfer
This conflict is reconciled by the use of bore cooling. Figure 2.32 illustrates that by boring the upper part of the liner at an angle to the longitudinal axis the bore at mid-point is close to the surface of the liner. The close proximity of the liner surface to the cooling water results in effective heat transfer. By using this technique of bore cooling good heat transfer is accompanied by high overall strength
Maintaining the correct surface temperatures in the vicinity of the combustion space by good heat transfer does however cause the risk of low temperature corrosion or cracking occurring in the lower portions of the liner. The solution to this problem is to either insulate the cooling water spaces that are at risk, or utilize a load-controlled