Packard Forum Index » Pre-War (1899-1942)

Depends on the filter. The prewar factory canister type filters appears to have needed an orifice added as when the bypass filter plumbing was adopted Packard issued an article advising mechanics to solder a fitting closed and then drill a specific size hole thru the solder to ensure a restriction was in one of the fittings. After the filter plumbing change the factory supplied brass blocks or elbows had the orifice already incorporated.

Postwar factory filters appears to have had the orifice in the filter assy which consisted of one or two small holes drilled in the center pipe. Aftermarkets probably had the same arrangement. I would examine your filter carefully to see if it has the one or two fairly small holes (1/16" or less) in the center pipe. If larger or if there are multiple holes, does one of the side outlets in the 4 way brass block at the engine or one of the 90 degree elbows on the filter have a small hole in the port. If the filter has been on the engine all these years chances are there is an orifice somewhere and the rubber hoses are just a connection.

Thanks to all, I'm going to run the shorter filter in my original photo thanks to Howard's explanation. Where do I find a copy of the data book? I will check for an orifice.

You can download a copy of the 38 data book from the literature section on the website.

packardinfo.com/xoops/html/downloads/1938_PackardSixEightDataBook.pdf