Tomei Beryllium Copper Valve Seat Ring Set For Subaru WRX/STI EJ20/EJ25 Engines

Tomei Beryllium Copper Alloy (BeCu) Valve Seat Ring For Subaru WRX/STI EJ20/EJ25 Engines

Specs:

Seat Ring Outer (mm): Intake (37.6) / Exhaust (33.6)
Tolerance (mm): Intake (+0.03) - (0.00) / Exhaust (+0.02) - (-0.01)
Head Seat Recess (mm): Intake (37.5) / Exhaust (33.5)
Head Seat Recess Tolerance (mm): Intake (+0.02) - (0.00) / Exhaust (0.02) - (+0.01)
Seat Ring Height (mm): Intake (8.3) / Exhaust (8.3)

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). We select 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.

Note:

1. This product is made from beryllium copper alloy (BeCu). The Beryllium sintered alloy has different thermal expansion characteristics so the cylinder head machine process will be different. Please be sure to match the reference value. Please follow the official service manual for reference to the other components assembly process.

2. This product is 0.5mm larger than stock. The outer surface is already polished and is ready for installation. Please do not polish, machine, or modify the outer surface.

3. Please do not use leaded gasoline fuel with this product as it will cause accelerated abnormal wear.

We usually ship all orders within 1 day unless there is an issue with the order. In that case, we will contact you to find the best solution.