Packard Forum Index » V-8 (1955-56)

Though I lurk here sometime, its been awhile since I'd had anything worth posting. But a recent experience with the 352 in my beloved 56J may be worth mentioning.

I have owned this 56J since 1986, at 81,000 miles. It now has around 235,000 miles, so have first hand history.

I had rebuilt the short block over 90,000 miles ago, and the heads over 120,000 miles ago (included hardened exhaust seats), in the 1980s-90s.
Over the past few years and 10,000-15,000 miles, the 352 had progressively became ill: lost pep, lost MPG, ran at lower vacuum, and recently would only wind up to around 3500 RPM before valve float, so I decided to investigate.

About 15,000 miles ago, I had installed a newly reground (Effingham)cam and new set of (Terrell)lifters. Upon run-in, I noticed some of the pushrods were barely turning. On the several other 352s I have had, they usually spin at not more than 10 seconds per rotation. A recent inspection before teardown of this 352 revealed several of the lifters were not rotating at all. So, I figured in addition to normal wear & tear, it had a cam problem.

Upon teardown, the lifter bottoms were shot: one had a groove worn straight across it, and most of the others had a splotched wear pattern instead of circular. (Indicative of not enough spin.) The cam also had a weird wear pattern.

So, I had Jack V. send me a reground cam. After install of Jack's cam and another new set of Terrell lifters, the pushrods spun similar to the Effingham cam. So, thinking maybe I'd gotten some offshore lifters, I had Jack send me a set of (Johnson) USA lifters. Installed those with same, disappointing results.

So, after two cams and three sets of lifters, I figured it had to be something else.

Long story short, I figured out 14 of the 16 pushrod sockets in the rockers were shot. I replaced those rockers, and flipped all the pushrods upside down. The pushrods now rotate as they should.

Footnote: the heads were toast, but the bottom end looked great, and it still gets over 4000 per quart of oil. So with a fresh set of heads, cam, lifters, and rockers, I figure this 352 is good for another 100,000 miles :)

Quote:

Interesting failure mode. I don't believe I've ever heard of that before. I wonder: what caused the pushrod seats in the rocker arms to fail? Inadequate rocker arm oiling? IIRC, the pushrods in a Packard V-8 are hollow but don't have holes in the ends like in most other engines, so the oil on the rocker arm end of the pushrod has to come from the rocker, not the lifter. Usually, there's enough oil flying around under the valve covers that EVERYTHING gets oiled, but in this case apparently not.

Craig

Will try to upload a pic of one of the rockers.

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Hey JoeH

I think we are neighbors. You get bored and need another 352 to work on mine is out of the car for the next couple years as the rest of the work is being done. Just saying....

The way I figured it out was: with engine off, used finger & thumb to rotate each pushrod. I noticed the ones that hardly rotated had considerable more drag than the ones that spun like tops. Then, removed and disassembled the rocker sets, and visually inspected each socket. Next, with all parts clean and dry, rotated a pushrod in each socket, while holding it up to my ear. I could hear and feel the drag on the sockets that were wore out, and could hear/feel nothing on the others. Further, on the worst ones, if the pushrod was shifted side to side while in the socket, it produced noticeable clicks, more felt than heard.

I attribute the above problems to simple wear & tear. After all, this motor has around 235,000 miles on it. The system design, that affords minimal oil to the top end also likely did not help. But big-4 stuff also fails, sometimes sooner than later.

Have had the Olds pump on this motor now for around 15,000 miles, and it oils the top end much better.

Hi Stewart,
I agree, we are neighbors. Will definitely have to get together sometime. I could drive the 56J over your way sometime.
Not interested in doing anymore 352 work for awhile though :)

JoeH
I understand, I really do. This is my first Packard engine.
I knew you were out there as I saw some earlier post discussing your Olds oil pump. I am planning to do the same so I may pick your brain when that time comes.

That's good info, Joe. I never bothered to check rocker sockets. However, you may be driving the highest mileage Packard V8 ever. Probably no one ever was able to wear out the rocker sockets before.

It must have been a problem for those transmissions which would run enough miles, because while Packard, Mopar and AMC used 1/4" pushrod ball ends during the '50s. The result was too much point loading and resultant wear. Mopar and AMC went to 5/16" pushrod balls in early '60s.

jack vines