Packard Forum Index » V-8 (1955-56)

Hey thanks for all the input.

I'm the one who started this discussion about this problem that has been rehashed over and over again. In all of the other posts I didn't see anything about the cam plate.

I guess TSB 56T-20 was just another patch job by Packard.

I'm working on a 56 Carribean which went into storage in 1967 after a failed motor job. It already had a Packard replacement block number 2155 and is getting a junk yard block from a high mileage 400 which was beginning to spin #8 rod bearing. This will be the third block.

I advised the machine shop to carefully examine the block for any clue as to why the engine should develop low oil pressure after high mileage. But TSB 56T-20 indicates that these motors had oil pressure problems when built.

I remember original owner Clippers doing pretty well at higher mileage, but also Charlie Clancy had a Patrician with 99,000 miles on it. Perhaps there are good blocks and bad blocks as happens with other V-8's on occasion. It seems the smaller motors were doing better which is consistent with other makes.

I guess the route here is the Oldsmobile pump which probably puts out enough volume to keep the early thrust plate if the motor still has it.

There seems to be a lot of variation and the best running cars may have been run into the ground long ago and what is left are lesser cars that never accumulated much mileage.

Hopefully this junkyard block might be a good one.

Thanks for the help.

It's not clear to me why the block is changed 3 times due to bearing problems????? Thus far, noone has been able to determine WHY the bearings fail in theses engines. We just know that they do. Or at least there is significant evidence that the bearings fail. However, changing blocks is not likely to solve the problem. But then again, i don't have a better answer either.

Bowman. EARLY 55 V8's had a pee hole in the rocker arm directly above the push rod socket of the arm. It shoots out a stream of oil to keep the overhead well oiled.

The pee-hole was discontinued sometime after early production.

Disclaimer: I have never actualy analyzed any early 55 rockers. Never had one in my hand. My explanation about the early 55 rockers is based on reasonable research and other Packard owners claims.

See the oiling schematic in the manual for the engine. U will see oil path across the top of the rocker ARM.

Quote:

I have a set from a '55 320 Hash engine, what do you want to know about them?

Keith, like you I wondered at the drawing that showed oil being routed across the ridge on the rockers. When I did the heads on Best Other I borrowed several rocker sets from Owen Dyneto and installed 55 exhaust rockers. My thinking was same as yours. An expert mechanic told me that if there was a mist of oil in the rocker area that would be sufficient lubrication between the rockers and the tip of the valve stems. The hole in those rockers is VERY small. I don't know if it helped, but it couldn't hurt.

PackardV8, When I take my cover off I will check my rockers to see if they have a peewee hole. Like I said mine is supposed to be a late 56 build date, but,I have had other vehicles with parts from earlier models. One that still haunts my memory is,I had a 61 Mercury monterey (great car)with a 352 V8. I started having some tranny problems after about 15K, it turned out the wrong trans had been installed when built and was way undersized for the car.I was lucky, I found a new one (Real cheap too) that was correct for the car, installed it and no more problems.

Okay, The original block was replaced by Packard. I don't know how many times. I only know that the present motor number is for a replacement block from Packard. Take my word for the present block. It is no good. The motor blew up.

I think the suggestions as to the length of the oil pump shaft are very good. Perhaps the unit would function better if the shaft was modified into two pieces as were Packard oil pumps in the Eights and Super Eights (scratch that, I checked and the unit is built in two pieces). The V-12 also has oil pump issues and it has a long drive shaft as well.

As for chronic rod bearing problems, well, the air sucking problem will compromise rod bearings because oil foaming is very destructive. On the present block it is curious that the bearing closest to the oil pump was beginning to spin, but if it was getting the most air then that is an explanation.

The original pump did not have the relief valve modification.

I will carefully look at the camshaft endplay because if the cam moves back and forth too much that will cause problems with the oil pump. If the camshaft is already starving for oil that will cause a compounding as well.

The rest of the unit looks pretty generic - current practices using cross bolted main bearings and block stabilizers are far superior which is one reason modern motors last so much longer.

The bypass oil filtration doesn't help either.

PackardV8 aske if I would post some photos of the rebuilt oil pump I received from Bob Aller. Attached are some shots of the pump from my 56 400. If anyone would like some other shots closeups, just ask.

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What most of us would like to see is the drive shaft removed and a photo of the interior of the area on which the shaft rides. Also, what is the diameter of the shaft?

thnx, jack vines

Jack,
Attached is a picture of the shaft where it enters the pump. I don't have a micrometer so it's not precise, but the shaft appears to be 7/16". Not having the tools to remove the shaft, I think that will have to wait for another day.
Jed

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