Thread: Prefill Oil filters?

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OK - This was on another website tonight. Who here pre-fills their oil filters?

I see the importance of it on a first start-up but after the engine has been run and broken in, does it really make much difference? Even at the first 500 mile oil change? I'm talking routine oil changes, not drain the oil and refill next week.

I do it whenever I change oil. Less time to build oil pressure after an oil change. I only do that for the race motor with stiff springs and solid rollers. Not as big a deal for milder build... Never did it for my drivers.

-Chris

The question I have is how long does it take the oil pump to fill the filter and start the supply? I would think anything you can do to shorten this time would be a good thing. How long does it take to prime the filter? I have been doing it ever since it was explained to me. Made sense!

I just fired my 454 up after it was sitting for 7 years. After all the prep work I changed the oil and filter. I filled the filter up first I heard that tip also recently.

Richard

I always fill the filter on a oil change.

If the filter goes in staight up there's no problem filling it, like on my wifes new Caliber. But if it goes in say at an angle , you can put some oil in but I wouldn't fill it.

My F350 - just about horizontal, the Escape needs to be screwed around some other parts and is just about horizontal as well. The '31 is horizontal and it needs to be threaded past the steering, fuel line and a header. No I don't/can't pre lube the filters

I have never pre-filled filters on drivers. On the '33's new engine we pre-filled before priming the system, but that filter only holds about 1/2 quart or less so fill time would be pretty quick.

Originally Posted by sunsetdart

If the filter goes in staight up there's no problem filling it, like on my wifes new Caliber. But if it goes in say at an angle , you can put some oil in but I wouldn't fill it.

Same here. I always prefill them, only because that is what I was always taught and what I heard. It just seems to make sense that there is less wait time for the filter to fill and start lubing the rest of the motor.

Don

If easy, I would fill the filter (via the outer holes).

These are tiny engines with high oil pressure tho. Larger engines, we need to pre-fill them, prelube the motors, and blow down the cylinders before starting.

I do like the one system we have on cat gensets.... you can change the oil/fuel filter and fill it with filtered fuel while the engine is running.

A friend of mine way back in the 70's put a kill switch on his SBC Nova. He would crank the engine until the oil pressure gauge moved. Then he'd hit the kill switch which would energize the coil & electric fuel pump. I often wondered how many starters he went through?.....

does the oil go thru the filter before it enters the engine or go thru it after it has oiled everything ?

Every one I have ever seen goes through the filter first so the bearings get clean oil.


Don

Hoss, I've only ever seen filter first.
to avoid oil starvation there is normally a bypass if the filter is clogged. Sometimes a problem on REALLY cold thick oil tho as it bypasses on startup.

How many revolutions does your engine make before it has circulated oil thru it? Depending on where your sending unit is mounted and wether or not the engine is warm. If your idle is 750 and the engine is warm and there is a 2 second delay (12.5) revolutions.
Now I have a new question. Is the oil sending unit generally on the inlet or outlet side of the filter?