Re: Mythbuster #777 Fram Oil Filters

Posted by fred kanter On 2011/6/20 23:38:23

Re: Burst strength.

An engine oil pump output presure at maximum is about 80 psi and that is when the oil is cold and thick. The oil filter bypass valve's purpose is to allow the high presure to bypass the filter under these conditions, so the filter never experiences the 80 pounds. They could make filters for just a little more money that would withstand 600, 700, 900, 1500 pounds...just use heavier metal.....but why??
The pressure will never get up to 20% of the 500 pounds.

Re: Size of particles:

The original filter in the 1930 Packard, which is where this topic started, had what is basically a cotton sock type filter. The filters you are debating are probably ( a guess )capable of capturing particles 1/10th the size of the original. The clearances in the 1930 motor are much bigger and do not need the fine filtration of a modern filter.

In my opinion it makes no difference, except that with a finer filter (smaller particles) you are trading filtration for filter life. If an old motor that has blowby etc and produces much more particulate matter than a new style motor, it will clog a microfine filter much quicker. When that happens you filter goes on bypass and you have no filtration.

There's no such thing as free lunch.