Packard Forum Index » V-8 (1955-56)

Ok, so I know there was a LOT of spirited oil pump discussion back in the day. I don't want to re-hash any of that. Put simply, I think we can all agree that the Olds conversion is a cure-all and the factory pumps (especially after xx,000 miles of wear) tend to be inadequate. However there are two promising options in the middle:

-Ross's input shaft lube port modification
- the Aller conversion

I'm skipping over the various old mods that no one likes such as the reinforced bottom plate.

Anyway, does anyone know exactly what the Aller rebuild was? I ASSUME you would turn down the input shaft slightly and bore out the bore slightly to accommodate the installation of a new bushing to take up the tolerance. But I don't know.

Or, let me put it this way. I have 3 oil pumps, of which 2 might be decent. I would rather spend $0 or $20 for a bushing to do a decent fix than $400 on a perfect fix on a car which won't be driven very often. What would you do?

Edit: Aller pump pics

Do what Ross does.

Pictures on my blog.

Thanks RH. I don't see much of a reason to not try that. If that drops the oil pressure too much I could always remove the oil filter. While that may seem like a dumb idea I doubt it would hurt anything much if driving like 1k or less between yearly changes. And better than low oil pressure.

RH's blog post

I also linked to Ross's original pics in my first post.

I don't remember that post.

Thanks

My dad's 56 was having a lifter problem. But has been quiet .

But if it starts again my plan is ross.s to keep original

I think I put 40K plus miles on that car before I sold it. 0 problems.

Quote:

Thanks Ross, did you have a bushing installed also, or just the drill modification?

If the former can you provide details on what is used?

The housing was already wallowed out. I had a machinist buddy turn down the shaft ever so slightly and make a bronze bushing to suit.

Thanks. I’m thinking of doing something similar if the input shaft shows signs of wear. It would be easier for me to overbore the housing than turn down the shaft. Need to get some dimensions when I get home.

I have this junky oil pump as a "spare" so I figured I'd mic it out. Surprisingly, even though it shows wear, there is only a difference of .003 between the shaft and bore. (0.496, 0.493) The unworn part of the shaft reads only .0005 higher than the worn part. Makes you wonder what the original tolerance even was.

I would be curious whether anyone has insight on whether these are good or bad numbers. (Note: my mic reads .0003 high... need to zero it sometime.)

The closest oillite bushing would be a 7/16 × 9/16 by the way. Another option would be a 7/16 × 5/8 with the hole bored with a 12.5 mm (0.492) drill bit. Just polishing the worn section in a drill would probably get you there.

https://oilite.com/product/AA515-09

For a bushing.

I used a cast iron valve guide and cut it

A machine shop had a boat load of different ones.

When he closes it will suck.