Oil Filter & 346 Flathead

[Virgil Perkins #19943]

When you add an oil filter to a 346 flathead (1941), do you use an additonal quart of oil (making it 8 quarts) for fill up? Is this addressed in any shop manual anywhere?  Thanks for any enlightment, VP

[Bob Schuman, #254]

Virgil,
With the added oil filter the capacity will be eight quarts when the crankcase and filter are changed. The filter soaks up about a  of oil. I doubt you will find this in any manual because Cadillac did not offer the filter.
When the oil pan is drained on a 41 Cadillac and refilled with seven quarts of oil, the dipstick will show almost one quart over full. If a 1942-48 style fill tube and dipstick is used in the same engine, it will show very slightly over the full mark. I just recently verified this on my 41. It appears the 41 fill tube as built by Cadillac goes about 3/8 too far into the engine, which could be corrected by removing, repositioning, and rebrazing the bracket that holds the tube to the block.
Bob Schuman

[Virgil Perkins 19943]

THANK YOU Bob for the info. The dip stick on my 41 shows a little over 6 quarts when filling with 7 quarts and the tube is  in the block as far as it can be. The first fill up was after a complete rebuild, so I know the pan was empty, and has been the same each oil change since. Thanks again, VP

[Bryson Talamini 21505]

Virgil, I have twice performed the same measurement on my 37 LaSalle with exactly the same result as you got.