Packard Forum Index » V-8 (1955-56)

A Pontiac V-8 (1955-79) has a similar oil system layout to the Packard V-8, i.e., there is a vertical hole from the horizontal oil gallery between the lifter feed galleries. On the Pontiac, this hole is usually just plugged rather than using it for an oil pressure sender like on the Packard. So the opportunity for trapped air at the top of the hole is the same.

In my years of experience building and maintaining these engines, I have never heard of any oiling problem on a Pontiac V-8 related to possible trapped air in this location.

Pontiac engineers independently designed the Pontiac V-8 before its debut in 1955 and they didn't have any issues with employment from a clearly dying company. There were never any "service counselor" like notifications about something like this. The last Pontiac V-8 had exactly the same oiling system layout as the first one although some other running modifications were made (e.g., from rocker stud to pushrod oiling and reversal of the flow of the coolant).

IMO "trapped air" in this location is a non-problem.

Craig

But did the Pontiac oil pump wear out in as little as 25K miles like the Packard pump????? Maybe the Pontiac pump never allowed or caused enuf air to pass into the trapping area to cause a problem.

The problem is not with any constant or neglegible amount trapped air. The problem is that the Packard PUMP sends sufficient quantities to the trap area to cause an air build up problem.

Proving or disproving the trapped air issue is ez enuf. Bleed it off to the oil filter.

The Packard pump is clearly deficient. The Pontiac pump was at least adequate??? Two different pumps.

ANd where was the early pontiac V8 oil fiter fed from?????

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It never changed and was full flow from the beginning (1955). It is on the P-side of the block at the rear outside. The oil flows from the pump into the block, makes a 90-deg turn, goes to the filter, back into the block and into the main rear cross gallery.

WRT to the Pontiac oil pumps: Pontiac had a standard volume and a high volume version. I'm not sure when the HV was introduced, but certainly within a few years as Pontiac was starting to produce high performance engines (1956 was the first dual 4BBL, 1957 was trips or FI).

I can't believe that the Pontiac oil pumps were any higher quality than the Packard, but certainly having a bolt-on HV version didn't hurt.

Craig

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Well then, putting on the new Olds pump would solve it, wouldn't it?

Craig