Packard Forum Index » V-8 (1955-56)

<p>PackardV8 stated:</p>
Quote:
<p>
This may be true, but the REAL PROBLEM is that the oil system is one big LEAK and the gear design in the Packard V-8 oil pump is completely inadequate in keeping up with the leaks as the engine gets older and wears, particularly the lifter bores. There is just no substitute for more pumping volume. The Olds HV oil pump outputs 20% more than the standard Olds pump which probably outputs more than the Packard pump.
</p>
<p>
Craig
</p>

Many thanks for the information, your opinions and observations. Regarding the picture of the gears in the pump housing with the cover removed, I always thought the path of the oil was around the perimeter of the gears to the other side, not thru the center where they mesh. Have I been wrong all these years?

The path u describe IS correct. So u have been right all these years.

ALSO NOTE: that the presseure relief cavity opens into and is fully exposed to the SUCTION side of the pump. (NOT evident in any pics heretofore)

Yes, the path is on the outside, not inside -- my bad, I should proof read my posts. However, the number of teeth and root volume argument still applies.

Craig

Yes, the Olds conversion DOES deliver significantly MORE oil. I have no intentions of returning to the Packard pump.

However i am still interested in the Packard pump analysis.
Two main question about the Packard pump is:
1. WHAT cuses the premature wear of the shaft and its support?????

2. Why do some pumps NOT wear and others do?????

Only two possibile answers i can think of:
1. lack of oil.
2. variation of foundry amalgamation of the casting material or shaft hardness variation.

1. WHAT cuses the premature wear of the shaft and its support?????

I'd think variations in alignment with the driving (distributor) shaft would be worthy of examining as a possible cause for the variations in pump life.

Yes. I tried to measure that 2wo different ways at 2wo diffent occasions. More on this later.
THAT raises another question:
What is considered GAAP legal for eccentricty thru out the rest of the industry for production built engines???

I came up with .003 to .040 inch runout but i can not trust the method i used.

I mite have to take a little sabaticle until tuesday.

FWIW, I've tried to determine the root cause of oil pump and main bearing wear. However, since I only work with engines and not complete cars, I rarely-to-never get the maintenance history of an engine. Without knowing the mileage, oil change history, oil level history, typical operator methodology, it is difficult to make the connections:

1. Many Packard V8s show evidence of main bearing wear/replacement early in life. More often than not the main bearings are .010". Was anything done to the oil pump at this time? Who knows?
2. Was the cause of the main bearing problem:
A. Lack of oil pressure
B. Infrequent oil changes
C. Aeration of the oil
D. Machining problems with the main bearing bores or crankshaft.
E. The lock-up function of the T-U. GM began experiencing main bearing and crankshaft wear for the first time in the fifty-year-history of the SBC when the lock-up torque convertors were introduced with the 700R4. Could pulling a heavy car in lock-up at low RPMs have been too much for an already marginal oiling system design?

thnx,jack vines
Studebaker-Packard V8 Limited

Jack, your 2E is thought-provoking. I've driven several dozen 55/56 Twin Ultramatic Packards and almost all of them (mine excluded for an unknown reason) really can "lug" uncomfortably after lockup when at speeds below 25 or 30. In some cases it can be quite pronounced - you may be on to something with that thought.

BTW, I've a bunch of the cam retainer plates in the cellar and can never remember which is the late "improved" one and which is the original. I believe one has 3 grooves and the other 4, can you tell me which is which?

Actually, lock-up torque converters were introduced in many GM vehicles in 1980 as an upgrade to a few previously existing transmission models. Their model numbers were simply suffixed with a "C": THM 200C, 250C and 350C.

The 700R4 wasn't introduced until the 1982 model year; used in truck models, it also found its way into a few passenger car models in the early years. 700R4 was later renamed the 4L60.

The 200-4R, based on the marginal THM 200, was introduced in the 1981 model year as GM's first overdrive automatic tranmission and was used in most RWD passenger car models. It was phased out after 1990, in favor of the 4L60 and its succesors.

I'm no engineeer, but have my doubts that the use of a lock-up converter was the culprit behind bearing failure in the SBC or the Packard V8.

Keith's point about "foundry amalagamation" certainly raises an eyebrow, though. In the absence of a genuine bushing, I wonder if the factory made a change in metallurgical specifictions for the second design pump body.