Boigevis EA888 oil-gas separator advantages
Boigevis engineers have solved the problem of "burning oil" through a large amount of experimental data analysis and multiple product improvements.
1. Diaphragm material upgrade: a leap from single silicone to composite materials
Original factory pain points: Silicone rubber has limited high temperature resistance (long-term working temperature is about -50℃~200℃), and it is easy to harden and crack under frequent thermal cycles of the engine, and the diaphragm tearing leads to oil-gas separation failure.
Boigevis solution:
Spunbond fiber reinforcement layer: provides a high-strength skeleton structure similar to Kevlar fiber, and the tensile strength is increased by about 300% (laboratory data), avoiding diaphragm deformation and rupture.
Fluorosilicone coating: The temperature resistance range is extended to -60℃~230℃, and the oil resistance is increased by 50% (ASTM D471 test), which can resist long-term erosion by engine oil.
Abnormal noise elimination mechanism: The 2.5mm thickened design (about 1.8mm for the original) reduces the high-frequency vibration transmission, and the increased material damping coefficient reduces the vibration noise by about 15dB(A).
2. External pressure relief valve design: Optimized reconstruction of fluid dynamics
Original defect: The built-in pressure relief valve causes a significant Bernoulli effect, and the high-speed airflow (about 12m/s) carries the liquid oil to form an aerosol, which directly enters the intake system for combustion.
Boigevis improvement:
External separation chamber: Through the 90° drainage elbow design and the centrifugal sedimentation principle (Stokes' law calculation), the oil droplet separation efficiency is increased from the original 85% to 93%.
Gravity reflux optimization: The height of the pressure relief valve is reduced by 25mm, and with the 3° tilt angle design, the oil reflux time is shortened to 0.8 seconds (2.5 seconds for the original), reducing the residual amount by 40%.
3. Oil drain hole expansion project: accurate calculation of fluid mechanics
Original factory limitations: 2.2mm aperture can only meet the flow requirements of SAE 5W-30 engine oil (viscosity 9.3cSt@100℃), and it is easy to produce flow resistance when facing high-viscosity engine oil (such as 0W-40, viscosity 13.1cSt).
Boigevis solution:
3mm aperture design: Based on the calculation of the Hagen-Poiseuille equation, the flow rate is increased to Q=πr⁴ΔP/(8μL), and the flow rate is increased by about 3.2 times under the same pressure difference.
Anti-siphon structure: A 0.2mm annular micro-groove is added at the orifice to destroy the surface tension and avoid secondary oil and gas mixing caused by the Venturi effect.
Self-cleaning function: Electrochemical polishing (Ra≤0.8μm) is adopted, the surface roughness is reduced by 60%, and the carbon deposition adhesion rate is reduced by 70%.
Verification data support:
Bench test shows that after 500 hours of endurance test, the oil consumption dropped from the original 0.3L/1000km to 0.08L/1000km (in line with the EU ACEA C3 standard).
Actual vehicle verification: On the EA888 GEN3 engine, the oil level drops by no more than 1/4 of the MIN-MAX scale during the 5000km oil change cycle.
NVH test: The diaphragm vibration frequency is adjusted from the original 2800Hz to 3200Hz, avoiding the main resonance frequency band of the engine (2500-2700Hz).
Technical foresight:
The design has passed the German TÜV weather resistance certification (-40℃~150℃ cycle test 1000 times), adapted to the National VI B emission requirements, and can reduce particulate matter emissions by about 22% (WLTC working condition test). It is recommended to use with low-ash engine oil (such as VW 50800/50900 standard), which can further extend the DPF life by more than 30%.
This upgrade solution reflects systematic innovation from material science to fluid dynamics. It is recommended to clean the PCV pipeline during installation and use a torque wrench (8Nm±0.5Nm) to assemble it in a standardized manner to ensure optimal performance.
