Packard Forum Index » V-8 (1955-56)

So out of curiosity, what is the problem with the 55-56 V-8 oil pumps? Parts hard to get, or poorly designed??

John

Be interesting to see the responses on this question. Given the basic theory of air is being drawn into the oil stream and interrupting sufficient flow to the lifters, then given your two criteria I think design will win out.

There are are any number of opinions as to what causes the issue and I don't believe any have been proven conclusively.

Some theories I can recall from posts on the subject and ads from various places for "improved pumps" over the years are:
1. The relief valve and port was improperly made and positioned so air can be drawn in during operation. That was apparently a factory thought with the addition of a kit having a bent tube to position its end always below oil level. A second design pump was introduced but I am not sure if anyone has documented exactly what the changes were.
2. There are no bushings to support the shaft so it can wear the cast iron body and start to wobble allowing air to enter. I believe the body was machined and extra bushings were installed in the Aller fix.
3. The pot metal separator plate between the oil and vacuum pump sections was too weak and deforms under pressure which allows air to be drawn in at certain spots. That was the idea in the PI reworked pumps which removes the vacuum pump and adds a thick steel bottom plate in its place.
4. Not enough capacity so any loss from bearing wear or any drawn in air can overwhelm normal flow. Believe that is the thinking behind the Olds pump upgrade and which seems to be the best solution so far.

EDIT: I stand corrected on the type of metal in the separator plate between the two pumps.

THe post by HH56 above pretty much sums it all up.
However a minor correction:
The seperator plate is not pot metal. IT is steel. The vacuum pump body is pot metal and rather flimmsy.

In a nutshell. the OEM Packard pump is weak thru out. Several band-aid campaigns were offered by PMCC to "fix" the problems but they were at best just band-aid fixes just to appease the customer and dealers.

Anyone that really wants to study the details of the OEM Packard Oil pump issue can do a search on this website.
Better be prepared to have meals deliverd to the house and a weeks vacation from work to read all of the posts about it. Mostly from the 1999 thru about 2008 time frame.
Read thru all of those topics and posts and then u'll know everything there is to know about the Packard oil pump.

The Bendix Treadle Vac too!!! Happy reading!!!! LOL. LOL. LOL.

IMO you really have to view the oil pump situation within the context of the entire engine oiling system and I think even at this date we still lack a complete and total explanation for the problems that arise with the engine oiling. Part of the problem in gaining a full understanding is that some V8s like my own have gone nearly 100,000 miles with no engine work whatsoever, and running the original oil pump and has experienced no problems at all; yet others have developed all kinds of valve lifter clatter and excessive bearing wear at less than 1/2 that mileage.

It was not uncommon for first generation new engines to have oiling issues - look at the 1955 Chevrolet 265 V8 which had its share of problems - but they were resolved quickly in part due to the very large volume of units produced. Packard for several reasons did not have the opportunity to fully evaluate and correct their issues. Twice they changed the oiling of the rocker shafts to increase pressure to the lifters, later added oil baffles to the heads, changed to a different hydraulic lifter, and they made several alterations to the oil pump, yet short life on many engines due to poor oiling remains so it seems Packard never fully comprehended the full causation.

Some have placed blame on the combination vacuum and oil pump, yet it performed OK for General Motors who used it for a few years in Cadillac and Buick. Surely the oil pump could have been designed better and most criticism is aimed at the lack of a proper shaft bushing at the driven end, a prevalent therory being that wear eventually allows air to be sucked into the oil stream. Hence the observation by many that simply running 1/2 quart of oil over full solves the lifter clatter problem.

Certainly there are others here far more knowledgeable than me on this and I'm sure they will offer different opinions - if you're really interested there are dozens and dozens of articles and posts on this topic, some dating back to the earliest of days, enough reading to last you the rest of the year if you so wish; my opinion is that we still lack a full understanding.

I'll toss in my two cents: I have also seen engines with 100k + miles and no oiling problems, and those at 40 that were disasters.

For certain many of the pumps had excessive wear at the input shaft and drew in air there. Well of course Packard did not put bushings there, I am not aware of anyone's oil pump that had bushings; everyone ran a steel shaft in a cast iron body. Given that some pumps worked quite OK and others not, my guess is non standard variations in the materials, or alignment/machining problems.

Since Caddy and Buick used similar pumps I guess they were from a supplier.

I'm pretty sure not everything was up to snuff at the Utica plant as I have often seen alignment problems cause the early demise of Ultramatics. Many 55s will show heavy wear on one side of the reactor shaft, a sure indication of misalignment.

There is a document floating around of defective engines and trans delivered to AMC for the big Nashes and Hudsons in early 55. It is an extensive list by engine number and the defects are pretty horrendous--everything from missing bolts to engines with no oil pressure. Starting up an all new engine plant is no small feat and Packard had their hands full on that front, quite aside from what was happening at Connor.

Now before the "I hate Nance" brigade rouses out of their beds to pointlessly rage in stunning futility about decisions we are not informed enough to understand, let me add:

Virtually none of the production machinery used at East Grand to produce straight eights was usable for producing V8s. A whole new facility was a practical necessity and it made great sense to use space in Utica rather than set new machinery up at the Boulevard on multiple floors. Odd quality problems can hardly be avoided in such situations, but it was extra unfortunate that the problems were so intractable or the staff overtaxed that they continued as long as they did.

Harold Churchill,chief engineer at Studebaker did once comment that in his opinion there there was not enough "banking" between machine operations at Utica. That is, a bank of parts that have completed operation 1 before going to operation 2. In that way, if there is a problem at operation 1, operations 2 and 3 etc can keep going till operation 1 is corrected. It is very nice economically to keep these banks to a minimum, but on the factory floor it is very nice to have them so the people farther down the line from the problem are not standing with their hands in their pockets waiting for parts to process. I speculate that with inadequate banking there was pressure to keep the line moving even if a particular process was a bit out of specification.

If i had a pump that i knew had ran 100K miles with no problems then rebuild the Packard pump.

BUT, if i have a pump that has failed in say 40K miles or less then convert to the Olds pump.

Anything unreasonable or lacking in rationale about that???

Somewhere back in the blogs referring to the oil pump problems was a user that had a unique theory.

Basically it was: depending on your engine number which could be traced back to a certain process at Utica, one could guestimate the probability of a good engine or a bad one.
I don't remember which process, boring, machining, etc., but supposedly if your engine came down the good line you would get no discernible problems for miles and miles even with the poorly designed oil pump. I seem to recall there being either two or four machines (or workstations)that were involved in his theory.
Whether the problem was tolerances or assembly of (sub)average parts instead of better than average (they were supposed to be "Master Motor Builders", remember) I don't recall.

I don't remember either if the theory was in its own blog or buried in another but I thought it was an interesting one and I never heard of this one since. So for its validity, who knows. I do remember his asking people for their engine numbers.

A good pretty even discussion of the problem above. As one of the original developers and maker of the Olds oil pump adaption, here's one of my web pages about it. Also involved to a significant degree were Keith (PackardV8), Kevin (KevinAZ) and Eric (Turbopacman). Now, Jack Vines makes them and ships them world wide.

1956packardpanther.com/PV8C/PV8C_OHVOPA.html

Craig

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