Packard Forum Index » V-8 (1955-56)

The Packard V8 was only in production for less than a year and used in four different marques over two model years, 1955 and 1956. As with any new engine design, there were some problem areas with the Packard V8 which required redesign.

Chief among these is the oiling system. Early on, Packard Engineering began a series of improvements aimed at alleviating the valve lifter clicking at hot idle. They made three separate service changes to the oiling system:

i. A service kit with a J-shaped copper tube to place in the outside of the pressure relief plunger bore and extend below the oil level in the pan. This didn’t solve the problem.
ii. A running production change of a revised cam retainer plate and spacer to go from full pressure oiling of the cam chain to intermittent. This helped maintain higher pressure to the right front lifters, but wasn’t the solution.
iii. A redesigned oil pump pressure relief system. These were late in the production life and are consequently very rare today.
iv. A fourth modification, made by some of those servicing the Packard V8s was to eliminate the vacuum pump and replace it with a thick steel bottom plate. Again, an improvement, but not the solution.

As we have learned with the benefit of years of observation, the design flaw in the oiling system was inherent and couldn’t be cured by band-aids. The oil pump used in the Packard versions of the engine is basically the same as that used by Cadillac, both with a vacuum pump piggybacked below it. The problem with the Packard application is to have clearance for the vacuum pump required the oil pump to be high in the pan, the top being above the oil level.

Then, there’s the very long unsupported oil pump drive shaft used by Packard. Chrysler engineers designing an equally long drive system, placed a bronze bushing in a passage in the block to support the oil pump driveshaft. The Packard V8 does not have this bushing and as the miles and revolutions pass, the unrestrained forces wear the top of the drive shaft bore of the oil pump body. When the shaft bore becomes excessively worn and being above the oil level, the pump begins to suck air down the shaft and aerate the oil.

It's time to note the oil pumps in the Packard V8s used in the 1955-56 Hudson and Nash and the 1956 Studebaker Golden Hawk did not have the vacuum pump, but still have the oiling problems inherent in the high placement of the oil pump and the long unsupported driveshaft.

I have been able to come up with three solutions to the oiling problem:

The first requires a complete redesign and rebuilding of the Packard oil pump. It begins with a 1955 Cadillac oil pump rebuild kit, including new gears and shafts. The Packard oil pump body driveshaft area is drilled larger and a cast iron bushing twice as long as the original bearing area is pressed in. A 3/8” thick bottom plate is machined with a bearing recess in it, so the oil pump driven shaft is supported top and bottom. This works well, but is too labor-intensive and thus too expensive for most to afford.

The second also uses the new Cadillac gears and shafts in the Packard pump body, but without the bushing or the bottom plate. This has proven successful for the limited use most hobby cars get these days. It also has the benefit of being able to retain the vacuum pump for those Packard owners who want total originality. Still too much labor, but available for those who insist.

The third, most common and least expensive, is to replace the Packard oil pump with a late Oldsmobile V8 oil pump and pickup. This concept was developed by three members here several years ago. One of the members tried producing the adapter kit via manual machining. This was too slow and too expensive and he was not able to do the final development necessary to perfect the kits.

I was asked to take on the project and was incredibly fortunate to know a couple of talented machinists who would write a CNC program to produce the adapter kits. Without this happy coincidence, hundreds of Packard V8s would be dead in the water.

The adapter kit consists of a very intricate doorstop-shaped steel adapter block, a steel driveshaft to mate the Packard distributor with the Oldsmobile oil pump and the bolts and printed instructions.

Installation requires dropping the oil pan, removing the OEM pump, plugging the vacuum line hole in the side of the block on the Packard versions, installing the new parts and refitting the pan with a new pan gasket.

The combination of a new oil pump placed lower in the oil has been the solution for most of the Packard V8 oiling problems.

There is also a high volume version of the Oldsmobile oil pump and pickup. The only time I recommend using the high volume unit is on an engine with enough wear in the main bearings to show low oil pressure.

The 2022 costs for these are:

Oil pump conversion kit - $250
Oldsmobile oil pump and pickup - $150
High volume Olds pump and pickup - $250
Shipping - $10 to $20 depending on which is ordered.

We’ve sold hundreds of these kits and they’ve been shipped all over the world. Who knew there were Packard V8s in Tasmania, India, Australia, New Zealand, Sweden, Norway, Germany, France, et al ?

If anyone reading this thinks he might ever need one of these kits, I suggest he order one now, as they are being made as a favor to me; neither I nor the favor are guaranteed to last indefinitely. Personal check is OK.

Studebaker-Packard V8 Limited
Jack Vines
3227 E 28th Ave
Spokane, WA 99223
(509) 953-6023

An excellent article by an expert.

I'm working on a 56 Senior (with original 374) showing a credible 110,000 miles. The oil pressure jumps to 45 psi instantly and remains there at all times-warm or cold,highway or idle. If I turn the idle down to the point of stalling it will drop to 35 psi warm. There is occasional lifter noise after sitting for a few days but it goes away right away.

Good news; Except-I pulled the left valve cover and see an excellent oil flow with a lot of tiny bubbles flowing by.

The history of the car is not known but the engine has not been apart in the last 30 years. So it doesn't have the Olds pump. The car is going to see some highway use and it won't be babied.

I'd love some advice about the best course to take. Should I overfill the crankcase and hope the air intake is cut off? With good pressure how much of a threat is this to the bearings? I'd like to avoid the pump conversion at this time if it doesn't pose too great a risk but a rod coming through the block isn't a pleasant thought.

Thank you

A rod through the block is not a typical failure mode.

Run an extra pint of oil and hope for the best.

jack vines

Update - the kits are back in stock and the backorders have all shipped.

jack vines

Quote:

The Olds pump is just the latest "fix" but so far it seems to be the most successful. Engine not being apart in the last 30 years does not rule out it having an Aller or PI modified pump.

The PI pump was heavily promoted nationwide as a "fix" thru the PI publications in the 70 and 80s and many were installed. The Aller pump was probably done in the same timeframe but not sure how much promotion it received. I do not remember seeing anything about it on the west coast but I have read about a few being installed in other parts of the country.

While the Aller mod did address perceived shaft wear issues, the PI version did not. It was solely made to address the perceived issue of the vacuum pump separator plate swelling and letting air enter. If worn shafts are the root of the problems Pi did not address that so if you are seeing bubbles you still might want to see what pump you have and consider the options.

Do any of these modified or replacement pumps change the pressure relief valve setting? From what I've read, Packard originally had their pressure relief set at 45 psi. Cranking the pressure up higher than that would only increase oil pump and drive wear further, and perhaps cause problems with too much oil getting pumped into the top end.

My car had an Aller pump, later swapped to an Olds oil pump before I bought it.

Oil pressure is 65PSI cold at any RPM.

Oil pressure warm is 35-40 running and 12-15 idle.

Talked to Ross and he said the higher oil pressure should cause no problems.

I used the rebuilt Aller pump and it worked for a while. Later I had the problem start again.I ordered the kit and had it installed. Now my oil pressure gauge is pegged and I am pushing oil thru the rear engine seal.

Quote:

Did you install the kit with a high volume Olds pump or the regular output version. Several have had that same complaint with the leaking seal after installing the high volume pump but don't recall anyone mentioning the issue with the regular.

Not sure if high volume would affect the pressure unless volume is so high or bearing clearance is tight enough the normal bleed off around bearings and valve train cannot happen fast enough. If volume is not the cause, wonder if the pressure relief valve works the same as Packards and if it could be faulty. I think you could change output pressure on Packards with a different spring. Wonder if that would be the case with the Olds if the problem cannot be traced to something else.

I'm not being critical, but not every engine launch had problems. The 49 Caddy and 51 Chrysler Hemi success killed Packard the antique Chrysler transmission notwithstanding. The only way Packard could have survived would have been if the 55 product launch was thoroughly tested and trouble free.