Switching to a bypass twist-on oil filter

June 1, 2018 | By Staff


I have a 1950 Plymouth with a factory flathead six-cylinder that I have owned for 50 years. When changing oil and replacing the oil filter, I find the replacement filter can be very hard to find and very expensive. Do you know if anyone has a conversion kit to allow the use of a modern screw-type (Fram) oil filter?


There are adaptors that will allow you to use screw-on filters rather than the old canister types, but you must get bypass-type twist-on filters to work with them. The modern twist-on direct filter will not work with a bypass system.

The old bypass filters were not as good as the modern cartridge types, and in the day of your Plymouth, they were extra-cost options anyway. If you don’t like dealing with the one on your car, you could just leave out the filter, take off the canister and fittings and change your oil every thousand miles as they recommended when the car was built. Oils today are far better than they were back then, and if you do frequent oil changes, you can easily do without that bypass filter. Many people did so in the old days.

On the other hand, Wix makes an adaptor base (part 24755) that sells for a few dollars, and is easy to install using simple hardware store brackets and bolts. The twist-on filters that work with it are Wix Part numbers 51050, 51051, 51320, 51704. Wix is a large manufacturer of automotive filters of all types. You can reach them at:

Wix Filters 1 Wix Way P.O. Box 1967 Gastonia, NC28054 (Product information) (Technical support) Wixfilters.com