Packard Forum Index » V-8 (1955-56)

Packard sold the V8's and Ultramatics to Hudson/Nash for their top-of-the-line cars in 55 and 56. There are some differences regarding part interchangeability which will be delineated here, along with the practical effects.

Engine & Accessories
Engine Pan
The well (big dip) in the pan is shifted forward on the Hash type to make room for something at the rear of the engine, presumably the steering linkage. This will interfere with the Packard steering linkage which must be in front of the well, so the pan is not interchangeable. (Edit: see photos.)

Distributor
Hash used a dual-point. No problem to use on a Packard car, just buy the Hash parts and follow the Hash manual.

Engine Oil Pump
Hash deleted the vacuum pump and replaced it with a plate. See drawing below (Edit: the drawing is of a 56 Golden Hawk pump, but is similar to the Hash type; notably, the Hash type is of a slightly different overall design, has a support hole for both shafts, and only 4 attaching screws, see photo). See "Fuel Pump" below.

Fuel Pump
Hash used a combination fuel and vacuum pump, AC 4293, which requires a 1/4" pipe street elbow 90 to fit the adapter hose 419506. The fuel and vacuum lines are also different and are not useable on a Packard except probably the carb to vacuum pump line. The balancing valve should be deleted, and the vacuum line to the firewall either connected to the wiper motor directly, or connected with a tee to the washer as well. The balancing valve may be retained if the extra lower port is capped. Otherwise, best hope it doesn't leak.

Carburetor
Hash used a Carter WGD 2231 as opposed to Packard's WCFB 2232. The WGD is a two-barrel and would use a different intake manifold, though on my engine, someone already swapped it for a 4-barrel manifold. The Hash 2-barrel manifold is probably the same as the 56 Clipper 2-barrel, though I don't know for certain as I don't have either.

Fan
Hash used a five-bladed fan instead of a four-blade fan. Doesn't matter one way or the other...

Engine/Transmission Mounts
Surprisingly, these are the exact same. Reminder: for Packard, the transmission mount must be rotated such that the mount-to-tailshaft bolt holes are behind the mount-to-frame studs, not in front.

Transmission
Transmission Cooler
In this photo the cooler unit is obviously different than the Packard type, and in a different location. The water manifold on the engine is the same though, so the Packard type may be substituted without issue. The holes are tapped in the block as well, just probably filled with 70 years of grime (ask me how I know).

Tailshaft (Packard # for 56th Hash type: 6470267)
Hash used a torque-tube driveline (or something) so the tailshaft is completely incompatible with Packard. It can be replaced with any Twin Ultramatic tailshaft assembly, without issue, subject to the design (55 or 56) of the transmission (i.e. a 56th tailshaft for a unit with 56th components, and likewise for 55th; the tailshaft bolt needs to match the internal design to prevent undue wear).

Bell Housing
The Hash type has 4 extra mounting bolt blind holes near the top, facing the rear. This should work in a Packard without colliding with the transmission tunnel.

Transmission Pan (Packard # for 56th Hash type: 471053)
The Packard pan has its fitting on the right of the front side of the pan. The Hash is at the front of the right side of the pan. This makes the dipstick tube interfere with a Packard stock exhaust. A custom exhaust would probably clear it with some attention paid to the routing. I don't know the reason for the change, probably the same as for the engine oil pan (see above).

Dipstick Tube
See Transmission Pan (above). I have not thought to check whether the dipstick itself is the same.

Selector Shaft Outer Lever (Packard # for 56th Hash type: 6480756)
Must be replaced with one of the Packard types. Reminder: when the shaft is rotated so the set screw is vertical, the Packard lever will lean towards the front of the car.

General Construction
As far as I'm aware, the Hash transmissions were made the same as the Packard sedan transmissions, and updated with the latest changes, to stay aligned with the current Packard models.

Attach file:

---

  oil pump body section.png (154.05 KB)


  20240407_185559.jpg (2,194.74 KB)


  IMG_3591.jpg (553.45 KB)


  IMG_3593.jpg (291.31 KB)

The oil pump end plate same p/n as 56 Studebaker Golden Hawk

See my edit below. I misremembered what that drawing is for; it's the 56GH drawing. The Hash pump is significantly different.

In my '56 Caribbean I have the balancing valve installed on the firewall and all the lines appropriately hooked up except for the ones that go to the actual vacuum sources at the rear carb and original oil pump. At engine rebuild, the original oil pump was replaced with the Olds pump. I procured a dual action fuel/vacuum pump and installed it on the engine. Previous owner retrofitted the vacuum wiper motor with an electric one. I went back to the original set up, see firewall photo and dual action pump photo. Wondering, one feed to the balancing valve connects to the rear carb and the other now would be to the dual action pump???? I have the original tube that connects to the carb, but I would have to fabricate a new line to the dual action pump. Noticed the dual action pump has 2 vacuum ports also, do you use both or just one and plug the other?

The Packard way was to have the vacuum sources in parallel, hence the valve.

The fuel pump type you should run a line from the carb to the OUT then run your IN line to the wipers. Delete, or cap the unused side of, the balancing valve.

Hash Pump
Regarding the Hash pump, there are a couple significant differences. The body is of a different overall construction. I'm pretty sure the gears are the same, which would make sense as to deliver the same oil volume. For whatever reason the Nash manual gives max. side play 8 thou and endplay 4 thou on the gears (Packard 5, 3 for reference). The Hash pump is a significant improvement in terms of gear support as the cover plate supports the drive shaft. On the Packard pump, the end of the driveshaft is flush with the end of the gear, so it is supported on one side only.

An important service note is that the float is much farther down on the Hash pump than the Packard pump. The lowest part of the top of the float is 1-5/8" below the bottom of the pump with the cover plate attached (for the Packard pump, the spec is 3/4" with the cover plate, i.e. vacuum pump assembly, removed). The easiest way to measure this is to simply set an assembled pump on the edge of a table with the float and tube hanging off the table, then measure from the top of the end of the float to the top of the table. This should never have to be adjusted, but it's helpful to know in case the body of a pump with a damaged pickup tube is being used to replace a worn body of another pump. The pickup itself is removable and interchangeable with the Packard pump.

Golden Hawk Pump
For reference, the Golden Hawk pump 6492360 has a 5/32" cover 6480507, compared to the Packard 1/8" cover. The Packard pump uses the vacuum pump assembly for additional structural support, and therefore it should not be removed if unwanted, but only the hex driving pin 440622 removed.

Transmission Lines
The Packard parts book gives the transmission line clips as being on the rear bolt of the front motor mount, and the other being on the flywheel cover bolt. On my Hash engine there were two studs that were 5/16-18 x 5/8 on one side, and likewise on the other except 24TPI, with a hex drive in the middle. Like a carburetor to intake manifold stud but with a "hex nut" separating the two halves, the entire thing as one piece of metal. I don't remember where they were exactly on the side of the pan, but they are used to clip the lines on. You can sort of see it here. It's also in the image below (the hex drive is not visible as the flange is in the way).

Attach file:

---

  hash pump.jpg (146.93 KB)


  Screenshot_20250604-101031_Gallery.jpg (2,033.16 KB)

According to the “How Potent is Packard’s V8?” article, the Hash 320 engine uses 352 heads, for an overall compression ratio of 7.8:1 instead of Packard 8.5:1. The article implies that the push rods would be different since the 352 head is 0.050” thicker than the 320 head, but I didn’t measure them nor do I have a copy of the Hash parts book. It should be noted that all 55th Packard engines use the same valve train components so I doubt that the push rods were different in reality, as the 320 and 352 blocks are the same regarding: external dimensions as to the head mating surface, piston stroke, etc.