Oil Flow Route

[icydude]

Which way does the oil flow around the filter.

I know the pressure feeds to the filter, but does it come from the oil pump into the filter through the middle hole or does it come from the pump through the side hole then through the filter and down the center?

[RB30-POWER]

it comes in from the small side hole, into the filter then exits through the centre hole and into the main oil block gallery

think about it, the pressure relief valve ball works like so.

if the oil is running through the side hole into the filter then exit via the centre hole and through the gallery behind the relief valve the pressure on both sides of the ball valve is equal so it stays closed and the oil goes through the filter.

if the filter was blocked, the oil would enter the side hole and not get through the filter, so the pressure on this side of the ball valve would be high and no pressure would be on the back of the valve, causing it to open and bypass the filter. (dirty oil is better then no oil, nissan decided)

hope that helps a little.

(might be hard to picture because on the twin cams, the oil goes through the factory oil cooler also, but on the sohc engine, the ball valve is directly in that bigger hole you see, should be blocked if you have factory oil cooler on the engine as the relief valve is in the oil cooler instead)

[icydude]

You confirmed my suspicious

Thank you