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

Is it safe to delete the oil filter on my 39 six and just put pipe plugs in the ports on the engine block? Car probably wont be driven more than 300 miles between annual oil changes. Thanks

Short answer is YES. Oil filters were optional equipment back in the day so plenty of Packards never had a filter to start with. And with your limited annual mileage I very much doubt any damage would occur. Only concern is in the "plugging ports" statement, you don't want to plug a vital oiling path and suffer the consequences. Other, more experienced members, will be able to advise which ports to plug or to run lines to/from.

To clarify, here is what the motor looks like without the oil filter. The curved line feeds the camshaft so putting plugs in the block is not acceptable.

Early on the filter was a shunt circuit that bypassed a metered amount of oil through the filter. This filtered the crankcase capacity about every six minutes.

Attach file:

---

  Oil Line.png (8.53 KB)

The above posted photo is too small to enlarge and see the port details on the engine but if the arrangement is the same as shown in the 39 Fact and Data Book, if removing the filter you must replace it with a connecting line or jumper tube between the two ports in order for the tappets and lifters to have a supply of oil. The second illustration showing oil flow with the oil circuit going to the left side of the block and then back would indicate two ports are involved in the flow. Not sure which is the feed side from the pump on your engine but on later engines it is the bottom port.

As is shown in the third photo, later year engines also had a two port arrangement and on those engines there was a curved pigtail (item 4) between the ports on engines with no filters. Even though sixes were gone by then, until around 1950-51 production on engines other than the 356, when adding a filter the pigtail was removed and the filter plumbed in so it took the place of the pigtail. Going thru the filter was then the only path available for the oil supplying the lifters. If the filter was removed the pigtail has to be reinstalled or the lifters get no oil.

Attach file:

---

  oil1.jpg (91.06 KB)


  oil2.jpg (172.75 KB)


  oil3.jpg (45.88 KB)

It shouldn't be too hard to make a bypass line, any thoughts on sizing- 3/16ths??

I would verify the tubing size. I cannot speak to 1939 engines but Packards from 1940 on used 1/4" steel tubing for the oil filter and pigtail lines. If the earlier block casting is the same I expect 39 did too. The tubing ID may be close to 3/16 but believe the common name description when buying goes by OD and is 1/4" tubing.

In either case, Napa (and most other parts stores) has both 1/4" and 3/16" precut lengths of brake line tubing. Napa lines used to be coated steel but with the current description of "Max Flex Alloy" Napa may have changed to a modern easier to bend cupro-nickel tubing. If you do buy precut they are often on a self serve rack at the local store. If so tubing gets mixed up and labels torn off so be sure to get lines with inverted flare compatible ends and US threaded nuts, not something mixed in that is metric with a slightly different end.

No idea of the distance between ports on the six engine but on later eight engines, with some creative less tight bends than the stock lines had, a precut 8" length of tubing can be used to make the pigtail. Longer precut lengths are available as is bulk line where you can buy the nuts and cut and flare the tubing to make whatever length you need. Copper tubing from the hardware store is also an option.

If the 39 block has the usual 1/8" NPT threaded ports you could also change the fittings to get an angle that will allow an easier or more convenient route to accommodate a precut length.

Attach file:

---

  Napa tubing.jpg (58.31 KB)

I would suggest just leaving it alone and changing the filter once every five or six years or so. Oil is not magic. Just drive the car hard a couple of times a year to get the oil good and hot and change the oil every 3 years with the miles you are driving.

Just curious...but why are you thinking of removing the oil filter? Ernie in Arizona

The oil filter on mine is a sealed canister and was meant to be replaced as a whole unlike the ones I am familiar with that had a replaceable cartridge. As far as I know they are not currently being produced and the NOS ones I've seen are pretty expensive. Another option would be to get one that has a replaceable element and adapt that to my car which I might do but I'd like to be able to run it in the meantime.

Then maybe you need to get a stock filter as what you described sounds like aftermarket. I have one for sale on my Packard / IMPERIAL page in the classified ads linked below which came from my original 1939 Six.