It is mainly about the modification of large power, the cylinder head and block parts should be strengthen to improve the reliability of engine(regardless NA or Turbo engine).this article explains the function and enhancement of each parts seperately, which is attracted more than 100,000 hits on Option FB fanpage.
Modification of cylinder head(1~5): https://carnews.com/article/info/2d95f0fc-e622-11e8-b3f3-42010af00004/ (Chinese ver. only)
1. Polishing the valve,valve way and valve seat can let the smooth surface reduces adhesion while intake and exhaust relatively which is increased reponsibility of throttle.
2.Reducing weight of valve(used in titanium alloy ) also can achieve the strength and better heat efficiency. Using valve rocker with bearing type can prevent distorsion of valve because of smaller friction.
3.Strengthening the valve spring by using Ti64 or Ti17 titanium alloy can improve fatigue life and reduce resonance which is changed high-cam shaft need a high tension of valve spring.
4.The purpose of high-camshaft is to increase the overlap time of valve especially at high RPM. It is used to increase oil-breaking RPM and the power is enhanced relatively.
5.The special material of reinforced screw can enhance the pre-tightening and clamping force in the cylinder head.It is usually with different pounds of screws according to the engine power.
Modification of cylinder block(1~6):
https://carnews.com/article/info/061befc2-e629-11e8-b3f3-42010af00004/ (Chinese ver. only)
1. Using forged piston and customise piston top design is lighten which has high intensity to handle strong explosion in combustion chamber.
2. Using forged connecting rods and due to the shape, the strength of middle part is always the key point. The shape I,X or H have different pressure resistance at same materials, such as the shape I for high RPM NA car and shape H is better for turbo car of large power.
3.Using forged crankshaft and cut like a axe shape which can reduce weight and rotational resistance and make Nitride process to increase the oil content.
4.Strengthening bearing on connecting rods that can be able to contact crankshaft more than the original. Also the tuner are measure connecting rods and crankshaft carefully,and the gap between the cylinder and crankshaft.
5. The cylinder liner which is used on heavily modified aluminum engine to strengthen the water way and cylinder wall.
6.Using metal cylinder gasket can hold up higher temperature while increasing turbo boost for heavily modified car.