Packard Forum Index » V-8 (1955-56)

Bowman: Disconnect and plug the oil filter FEED line from the head. Route a TEMPORARY 1/4 inch line from the oil pressure SENDING unit to the Filter. That is feed the filter from the same point that the sending unit is screwed into.

If that reduces (probably elimenates) the lifter clatter then u know the lifters are OK. Then u know the PUMP IS BAD. AND what u need is an Olds Conversion kit.

Packard V8, Many thanks for that info. I will do that as soon as I get my distributor problems corrected.
Now that I have my feet wet, another question comes to mind, that is, if there is a design or application problem with the pump or the actual oil flow in the engine(or possibly both) causing air bubbles in the oil flow in the block and the heads (especially the left bank)shouldn't that make main bearings #2 and #4 more prone to failure since they receive their lubricate from the left bank than #1,#3 & #5, and is there any evidence that is the case?
Another question, has there been any evidence in the failed engines of the oil return passsage at the rear of the left head being plugged or partially obstructed with debris. I would think that would create pump problems and early failure(I believe it is driven off the left side of the engine)as well as noises in the valve train and lower end as well. Or maybe the return is not of sufficient size? Just thinking outloud.

Before trying the reroute of the oil filter feed try overfilling the crankcase by ONE quart of oil. ez enuf to do.

The problem with the oil gallery is that the left side is fed from a point about 1.5 inch below the sending unit. The rite side is fed about 2 inches below the sending unit.
That means that any air that enters the system gets trapped at the 1.5 inches just under the sending unit. As the air builds up it then pushes down to the nearest escape which is the left gallery.

The idea of the reroute for the oil filter is to bleed off the air to the oil filter before it can push down to the left or rite feed gallery.

Quote:
"Another question, has there been any evidence in the failed engines of the oil return passsage at the rear of the left head being plugged or partially obstructed with debris. I would think that would create pump problems and early failure(I believe it is driven off the left side of the engine)as well as noises in the valve train and lower end as well. Or maybe the return is not of sufficient size?"

I doubt it. There is plenty of other places for the oil to drain back. I've seen SBC heads so caked up with crud that i had to use a screw driver to nearly pry the crud out of the drain back holes. It never caused any problem other than valve cover leak and some exhaust smoking.

Bowman,
In the case of your 41K mile original engine i'm assuming the pan has never been removed since new????

Either way, the valve seals have probaly broken up and plugged up the oil pump screen along with other debris. I've found this in my very original 34K mile engine and two others of unknown history.

Most likely the pump is also worn at the input shaft.

PackardV8, What you write about the sending unit makes sense but I thought the return was at the end of the head where the oil sender is located and the pumped oil came up into the front of the head. But the reroute seems like a pretty good idea and it really doesn't look as though that would be difficult to do.
But wouldn't adding another quart of oil to the sump pan make it more likely to have air in the oil or create too much splashing effect.

quote:
"causing air bubbles in the oil flow in the block and the heads (especially the left bank)shouldn't that make main bearings #2 and #4 more prone to failure since they receive .."

I kind of doubt it. As long as oil pressure is showing on the gauge then OIL is delivered. Perhaps along with some air yes but not enuf air to do damage. If there was enuf air to do damage than the oil pressure gauge would show very near ZERO psi or maybe only 3 or 4 pounds.

Let me put it another way:
The oil pump is an oil pump not an air compressor. oil does not compress. Only the air in the oil will compress. So some reasonably large amount of oil must exist in order for the gauge to read ANYTHING. Of course if the gauge reads ZERO then air is all there is in the system but that becomes a moot point.

I've driven PLymouth Chev and AMC 6 cyl engines albeit low speeds of say 25 to 35 mph around town for many miles while the gauge would drop to nearly zero at idle and i had to keep the engine speed up just to keep a little oil pressure. Those engines continued to run 25K miles that i know of and more after if fixed them.

I'm not sure what causes the main bearing premature wear yet. I'm guessing poor bearing insert material, oil gallerys too small or poorly drilled at the factory or maybe crankshaft flexing.

Most likely i suspect main bearing material inferiority first. But the oil gallery diameter and machining is the easiest and first to addreess. Crankshaft rigidity would be the most difficult to determine if everything else checks out ok.

Actually, a lot of people have found that the lifter noise and thus the air in the oil goes away when you over fill it by 1 quart. The Packard V8 is a mysterious beast that still holds a lot of secrets.

Adding another quart of oil simply covers up the open pressure relief valve port in the pump. it is a bandaid fix. It only REDUCES (NOT ELIMINATES) the air getting to the pump. Air can still get into the pump if the input shaft is worn sufficiently. But the amount of air is reduced enuf to cure the symptoms of clatter.

Effectively that is all the PMCC sump tube fix was. It was a CHEAP and dirty fix for the factory just to get around installing an expensive new pump.

THere IS enuf crankshaft clearence to allow for 1 qt. overfull. try it. Mite work. mite not. depends on other wear in the pump. it does NOT fix the pump. It only is a diagnostic or bandaid fix to get the customer out the door.

quote:

"What you write about the sending unit makes sense but I thought the return was at the end of the head where the oil sender is located and the pumped oil came up into the front of the head. "

???????

The oil filter as it came from the factory is FED from the FRONT of the LEFT head. The filter empties into the timing chain area via oil line fitting near the oil filler tube. As it came from the factory the OIL PRESSURE SENDING UNIT (that drives the gauge or lite) has nothing to do with the oil filter as it came from the factory.

My idea is feed the filter from the GAUGE sending unit and plug off the factory feed fitting at the front of the left head.