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Due to catastrophic failure of my 1947 356 engine, I am replacing it with a rebuilt 1940 356 which will match the car model. There is a distinct difference between the '47 filter and the filter that came with the non-running engine that I acquired. Part of that could be attributable to the full flow design for the '40 filter and partial flow design for the '47. But the '40 appears to be missing an upper element sealing cap that the '47 has along with a captured spring.




So the first question is whether the '40 filter (right) is correct, as shown, or is it missing the element sealing cap? Also, if the cap is missing, would the partial flow filter assembly (left) be suitable for use on the full flow engine?

The '40 engine appears to have low miles, and the front jiggle pin is confirmed to still be in place in the lifter gallery. So I prefer to stay with the original full flow design on this engine.

Any answers and guidance would be sincerely appreciated.

Don

None of the 356 engines were full flow as we consider that term today. What you might perceive to be full flow was only the oil going thru the filter and then to the upper port which is the feed to the valve lifter gallery. The rest of the engine lubrication -- bearings etc -- had the oil being supplied straight from the pump via drilled passages connecting from the main oil gallery which is a rounded protuberance that runs longitudinally down the right side of the block a few inches above the oil pain. That gallery is on all Packard inline blocks and an easy way to know if a later inline 8 is the 5 or 9 main bearing engine is to look at the number and spacing of pipe plugs on the side of the gallery. The plugs close the ends of the drilled passages to the main bearings although a couple located around the oil pump are not visible due to machining for the pump and its mounting.

Some 40 356 engines had noisy lifter issues which Packard decided was mostly due to restricted oil flow due to clogged filters but there were also unexplained reasons too. Packard went thru several revisions to the filter plumbing and canister/element assy before finally settling on the version you had in the 47 engine.

The 40 filter you have may have been one of the first attempts to solve the issue. First they tried a different element but that was not entirely successful and required dealers to stock two elements and for the lowly lube guy to remember which engine got which filter. Next step was to try a canister where they added a bypass valve which would open if the filter was clogged so oil could bypass the filter entirely. That was partially successful because there were still engines with intermittent noisy lifters but it may be the 40 filter you have.

They finally revised the plumbing by adding a second tee in the lower port. A short pigtail off the added tee went to the lifter gallery port to supply lifters with full flow oil pressure while the other tee supplied oil to the filter. A new hole was drilled in the block under the oil fill tube for filtered returning oil to drop directly into the crankcase. They then found the flow thru the filter was still a bit too high resulting in enough loss of pressure to the lifter gallery there were still intermittent noise issues so they added an orifice in one of the fittings going to the canister to restrict flow going to the filter to approximately 10-12 percent of the supply. That seemed to solve the issue and later engines had a 4 way brass block in the lower port in place of the two tees with the restriction on one of the side ports and a cast hole in the block near the distributor and just above the oil pan for the return. That solution carried thru on all 356 engines thru 50.

The same basic plumbing was used until 54 but the 48-50 288/327 blocks with solid lifters had the filter flow going to the lifter gallery again with no block port. That was OK with solid lifters but when hydraulic lifters became optional in 49-50 the noise issue was back so all 288/327 engines 51 thru 54 wound up using the bypass with return into the block. They also made a change in the flow thru the canister with the postwar canisters. Prewar oil into the filter was via the center tube and postwar it was on the side. While the filter will work either way and using the center tube in would be correct prewar, the relatively small inner area of the filter can clog quickly. The postwar side inlet lets the entire outer circumference of the filter collect dirt so is less likely to clog as quickly.

I would recommend you follow that last fix article to get the plumbing as close as possible to that on the 47 engine. Use the later canister which had the restriction built into the center tube and the 4 way brass fitting if you have it. You can verify the restriction is present by looking at the center tube and finding very small holes -- maybe 1/16 or less drilled in the tube. If you find larger holes then it is a transition filter and you need to add a restriction in one of the fittings as Packard originally did to restrict flow thru the filter. The drilled return hole called for may or may not be present on the 40 block depending on whether the engine ever had the mod but it would be a good idea to follow the instructions to add it.

There was one farther issue found in early engines after they aged that caused a noise problem and that was what they called a jiggle pin valve at the front of the lifter gallery. A pin was inserted thru a hole drilled in the plug at the front which admitted oil to lube the timing chain. When the hole or pin was worn the pin could fall out and the large hole allowed too much oil to get to the chain and the loss of pressure caused noisy lifters. The 47 block has a different type valve but your early block should have the pin. The valves are not interchangeable due to the block machining needed for the later valve.

Here is the pertinent info on the plumbing fix but if you want to read the whole saga look thru the service index from 40 thru 42 for various hydraulic tappet articles. IIRC, the jiggle pin issue is detailed in a later issue -- maybe a postwar article.

G'day Tweety,
to PackardInfo.

I invite you to include your '40 Packard in PackardInfo's
Packard Vehicle Registry.

Thank you, Howard, for the comprehensive enlightenment. The number of iterations of filter/plumbing development is certainly more extensive than I thought. With so much uncertainty about the ’40 set-up, I’ll proceed with transplanting the ’47 system to the extent possible and in accordance with the Service Letters. It has the 4-way tee with flow restriction in one of the ports, and it seemed to work quite well previously.

IMO, a good choice and all you should need to provide on the new (old) 40 block if it is not already there is the port for the filter to drain back into the crankcase. It was fairly easy for mechanics in the field to access the area and drill a hole where indicated in the bulletin. As I recall, 42 and later engines which had it cast in the blocks from the factory had it located low -- just above the oil pan -- and a bit behind the existing ports on the side of the block toward the distributor.