Again one of the most overlooked basics in engine tuning. This simple affordable upgrade is required to keep your valve timing in place and to avoid engine failure or from loosing the tuned settings you have speant time and money for.
The function of which valve sheet is asked, is maintaining air tightness with a valve, and generally wear resistance is required. However, with the engine used by high rotation and high load, the cooling performance of a valve sheet becomes very important further, and it is greatly concerned with an engine output. When engine is high rotation and high load, it is impossible to achieve high output from the engine if cooling performance of the cylinder is low and knock limit does not become high, since the temperature of the circumference of a cylinder head rises unusually. In racing engine that temperature needed to be carefully controlled, how much you can cool the circumference of the sheet ring is the important issue, and the technique of using high heat conduction metal, such as copper for a sheet ring, has been taken. Copper has one of the highest thermal conductivities through all metal that enables receiving heat from cylinder and cool it down quickly by transmit the heat to the cylinder head. (Degree of heat conduction: 1.silver, 2.copper, 3.gold, 4.aluminium, ... 10. cast iron - STD). TOMEI selects beryllium copper alloy (BeCu) that can secure mechanical intensity most in the copper alloy, which has ideal fatigue resistance and wear resistance while securing a preeminent cylinder cooling performance. They named it "bery-ring" and applied to the high performance turbocharged engine of market share in the world with beryllium copper so that they can offer this super-high grade material beryllium in affordable price.
| APPLICATION | IN/EX | PART NO. |
| MATERIAL | NOTES |
| RB26
DETT | SET | 162001601 |
| Beryllium | IN:12, EX:12 |
| SR20 | SET | 163100 |
| |
| 4G63 | SET | 163101 |
| |
| EJ20 | SET | 162010 |
| IN:8, EX:8 |
