I have a 1957 Plymouth belvedere with a flathead six in it and I wanted to change the oil filter but they do not make them no more so I was told that the oil filter was optional my question is how do I make it work with no oil filter on it
Do you have a container for a filter cartridge on the engine? They often times had a spin on fastener at the top. If you do, filter cartridges should still be available. A bit messy to change and you should have some way of getting the old oil out of the bottom of the filter container. Hand pumps are available that can do that job. The container was mounted at the side of the engine up top where it was easily accessed.
This was an option for the older flathead. They were made by Purolator or Fram (Mopar did a self branding too) and you can still find them on places like Ebay. It can be plugged off just by putting a plug into the two holes where the hoses connect to the engine as it was a bypass style filter taking a small portion (one of the fittings has a small orfice limiting the amount going to the filter) of the pressurized oil from the oil gallery and running it through the filter and back to the pan. Not nearly as effective as the full flow filters of today but it did get quite a bit of the small particles. There was even a company called Frantz that made a version that they just stuck a roll of toilet paper in it. It actually did a good job at filtering out some of the water that collected into the oil. I won't comment about its' other properties. I hated it when one of them came into the station as the element came out as a messy blob.
I've been using the Motorguards (Frantz competitor) on many vehicles over the years and they work great. Oil analysis reports have showed stelar results in everything from my old Mopars to a 2.7 on up to a Cummins diesel. The modern full flow oil filter was an invention of convenience and cost saving. The best ones don't filter much below 15um, and most run arounf 30um, which translates to increased engine wear. Yes, the TP rolls can be messy to replace, but with a little practice and know-how it's not that bad of a job. Bypass filtration will extend the useful life of an engine - not a bad idea in a car you intend to keep for awhile, or a truck you expect to put alot of miles on.
All filters produced today are set up for full flow. There was no provision made for a full flow filter in the older engines. Chevrolet introduced their full flow in 1956. The 1st generation Hemi had full flow in 1951. The flathead 6 was never updated to include a full flow system. The current aftermarket system could possibly be modified with a restrictor as used on the original system which probably was only about 2-3 gpm rated. The original system only had 1/8" or 1/4" pipe fitting connections (with a restrictor in the in side fitting usually at the block). There was no bypass valve or anti-drainback in them as they were vertically mounted and did not care if they emptied and if they plugged there was never a starvation issue. I have changed out bypass filters that there was no way any oil was getting through due to lack of changing them.