Packard Forum Index » V-8 (1955-56)

from above:
"The redesigned oil pump with the internal bypass is unobtanium."

Is there any other kind of Packard V8 pump with OUT internal bypass????
I have 4our pumps here, 1 is a late 56 plugged pump and one Hash pump. Thay are ALL INTERNAL bypass. At last 6 other pumps i've seen were all internal bypass too. I'd like to see one that is NOT internal bypass.

The 1/2 or full quart over full trick has nothing to do with the float. It covers up the PR port of the pump to keep it from sucking, albeit small, amounts or air.

If the float is set high enuf to tip up out of hte oil then the crank will strike the float.

CLRIFICATION: I can not remeber if the dip stick strikes the TOP of the float or it mite have been the TOP of the CRIMPED flange of the float. Either way, it strikes the float and it tis the END TIP of the dip stick.

Cut 1/2 inch from the bottom of the stick to cure.

Suggestion. Simpler is better. How about we just hereafter refer to the two Packard V8 oil pumps as "first design" and "second design"? That way, everyone will know to what we are referring without getting into arcane terminology such as "internal bypass without external passage" and "internal bypass with external passage".

As to the "second design" as being unobtanium, what percentage of production could we estimate was "second design"? I've seen very, very few. I've looked at the "second design" and can see no affordable way to modify "first design" pumps to become "second design", so the point may well be moot.

thnx, jack vines

"can see no affordable way to modify "first design" pumps to become "second design", so the point may well be moot."

Simple. Plug the PR port ala late 56 pump and drill 2wo holes in the side of the pressure relief piston.

JV wrote: "what percentage of production could we estimate was "second ...."

See STB 56T-20 introduceing the late 56 plugged pump about april 10th among other data that can ESTIMATE the production. Maybe Owen or someone keeps production figures, VN's, etc and similar data to jive with 56T-20. Get with them to narrow it down.

My 5672 1834 had the plugged pump and late cam retainer.

I'd like to know the estimate too.

I'm not that familiar with this subject, how do I identify the "second" generation oil pump from the external features? Is it the one with the threaded plug in the oil pressure relief valve? If so, what else is different about it? How much of an improvement is it, and in what ways?

You could estimate the # of engines that had the plugged pump, though I don't know how good an estimate it would be. Substract 1000 from the Utica#, and then subtract that from the total number of cars made with that Utica-numbered engine. For example for Caribbeans, C-1400 minus 1000 means the change occurred at the 400th Caribbean engine. Since they made about 537 Caribbeans, perhaps 137 were made after the changeover.

Quote:

Actually, as a prelude to developing the second design pump, Packard did a clandestine field test that involved plugging the port and modifying the relief valve on the original style oil pump - similar to what Keith has outlined.

In the end, they chose to go with the sump tube as a field fix - though the full reasons are unknown to me. Though service parts were available for the second design, that pump was intended for production installation only.

I've never performed an autopsy on dad's Exec, but strongly suspect it has the late design pump (and cam plate and spacer). The concern with the sump tube fix was that the relief valve was sticking and sucking air, but I'm suspicious that there may be other, concurrent, running changes involved in the second design that Packard didn't reveal.

(Edited by BH for latent typos - 11/06/2008, 12:23PM EST)

Owen writes: " I'm not that familiar with this subject, how do I identify the "second" generation oil pump from the external features? Is it the one with the threaded plug in the oil pressure relief valve? If so, what else is different about it? How much of an improvement is it, and in what ways?"


Yes, the threaded plug in the pressure relief port of the LATE 56 pump is CONSPICUOUS by external examination directly after engine oil pan removal.

The pressure relief valve piston is different in the late 56 pump. The casting number is also a different number.

Owen writes: "For example for Caribbeans, C-1400 minus 1000 means the change occurred at the 400th Caribbean engine. Since they made about 537 Caribbeans, perhaps 137 were made after the changeover"

ok. But, is it true that ALL other model production ceased when Carib production started???? OR just when Carib CONVERTIBLE production started???