[rnln]

My finger is still hurt. I took a filter out, looked into the hole and saw a big spring. Let see how much force needed to compress this spring, just curious. I use a flat screw driver to push on it. It is very hard, enough for me to jam my finger when the screw driver slipped, arggg. So look like there will be a chance, some situations, the oil will by pass the filter. Learn something new everyday.
Thank you everyone.

Can I come back to the second question?
What is the ID of the carrera stock cooler's fitting, anyone know?