1933 Super 8 crankcase archeology

[Super8]

Hello,

 

I am restoring a 1933 Super 8 engine. This engine came in pieces. Two of the cylinders were sleeved. This engine was fitted with 2 different types of connecting rods. 6 connecting rods were the Babbitt type with part number 210100. The two remaining ones were part number 221642 fitted with shells! When I overlay these rods the length and the bores match.

 

The Packard part took lists neither of these part numbers. It calls for PN 221641 (just one digit above the one fitted with shells). Furthermore, Packard explicitly recommends the use of Babbitt bearings and not using shells.

 

Does anyone have experience with this or would have encountered these part numbers?

 

Also, it seems that people who have used shells have experienced drastic loss of oil pressure. Can someone detail the reason behind it? Is it the lack of axial clearance on the crank pin?

 

Here are some pictures.

 

Thanks in advance for your input

 

 

 

 

[Guest SaddleRider]

where did you get the idea that "Packard recommended babbit" ?    A loss of oil pressure by using an "insert" type rod bearing?

 

Beginning with 1935 production, all Packard products (joining most of the rest of the automotive industry) used an "insert" type rod bearing.   For a very simple reason - with poured babbit bearings,  rod failure after only a few thousand (actually, in most cases only a few hundred) miles of high speed driving, they'd fail.  Once "insert" type bearings were available, the curse of rod bearing failure became a bad memory.  

 

Packard Super Eight engine production ended with the 1936 model year ( What was CALLED the "Super Eight) for the following year was the significantly smaller and less powerful "Standard Eight").  ( same stroke - smaller cylinder bore).

 

I cant help you with part numbers.  I can tell you that what you have is apparently a mix of pre and post 1934 connecting rod assemblies.  Be assured that a properly machined connecting rod bearing of ANY type will promote good oil pressure.

 

There are some dimensional issues in fitting modern "insert" type rod bearings to pre-war Packard connecting rods.   My recommendation is to get accurate crankshaft "crank-pin" dimensions.  Take those figures and one of the "insert" style rods ( to use as a sample)  to one of the manufacturers of modern connecting rods.   Modern "dimensionally correct" rods, machined to take a modern "off-the-shelf" insert bearing,  will give you the best result.

 

Yes - there are people who can re-babbit your connecting rods to an i.d. to match the journal diameter figures you provide.    If you know you are never EVER going to drive your car over, oh, say about 45 mph, and only on short trips on cool days,  poured babbit would be an inexpensive solution.  Given the fun of driving a car like yours around,  I personally think using modern connecting rod bearing technology is a far more appropriate solution.

 

 

 

 

[HH56]

The numbers on the rods may be casting numbers and not actual part numbers.  Packard frequently placed a number in a casting or forging for identification purposes and then after a machining step or two would list the item in the parts book differently.  Some would be a digit or two higher than the cast number and if subjected to even more machining would result in a part number with even more separation from the cast number.

[Super8]

Great thinking HH56. This makes sense.

 

SaddleRider - where did you get the idea that "Packard recommended babbit". It comes from the part book. See excerpt below.

 

 

 

 

[Restorer32]

Two names at the same time Pete? Unusual even for you.

[Owen_Dyneto]

The numbers seen on the connecting rods are forging numbers, not part numbers.

[Super8]

Assuming that I would migrate to 1936 connecting rods with shells, are the crank journal the same? Bearing inserts do not seem to be available either for 35 and 36. Do restorers use other cars insert bearings? I have heard Chrysler Slant 6 may work?

 

thanks for any advice

[Guest SaddleRider]

Quote

 

Hi again Super Eight !

 

In response to your posts:

 

First of all, I am absolutely astonished at what you found out  (that a Packard parts book - obviously an older edition than mine )  suggests "poured babbit" style connecting rods instead of  the  "insert" style.    Makes no sense to me.   Thank you for the info - I am baffled !

 

As best as I can recall, Packard went to a harder journal surface for 1935 production - but how that could effect a choice of bearing material I cant imagine,

 

I can tell you that when we could still find '35  - 36 Super Eights in wrecking yards,  we'd "pull"  their con rods for use in the earlier "big" eight engines.  Worked out great - crank dimensions should be the same.   Well - let me qualify that...micrometer time!     Bear in mind, down thru the years, who knows what was done to yours.  Ground under-size?    In those days machine shops were competent at grinding off the "off-set" counter-weights so the entire surface of the journal could be ground, then re-fitting the counter-weights (durn well better use a "Grade 8" bolt...!)  .   .  Just worn under-size ?  Wear patten mild enough so you are comfortable with new bearings ?

 

One thing hasn't changed !  The law of physics !  I trust you know you have limited margins on con rod bearing clearances for them to work right. 

 

If too tight, rod bearings cannot and will not " break in "...they'll just burn up. Too loose, and they'll knock, eventually tossing a rod or two thru that nice soft aluminum lower crank-case...!   

 

Improper machining for the "locking tabs" and the insert  "shell" will spin, over-heat, and next thing you know...a rather loud noise, and you are a pedestrian !     ( Over the years, I bet at least a quarter of the Stanard and Super Eight lower crank-cases I've seen,  had  evidence of one or more "patches" where a rod went thru !

 

Yes, there was a then late model Chrysler Corp. industrial engine insert bearing that would work fine in those later rods with a little maching,  but I've long since lost any paperwork I would have had from that era.

 

Without knowing for sure what I am talking about, I suspect whatever we were using in those days may have long gone "obsolete".   Of course even in the 1950's we could no longer get pre-war "Senior" Packard connecting rod bearings  direct from Packard or the orig. supplier ( Federal Mogul).

 

I don't recall where we, in those days,  got the idea you HAD to use '35 - '36  SUPER Eight rods for the Super Eight motor,  to get the benefit of "insert" style rod bearings in the earlier cars - looking at my parts book for that era, seems the "Standard" and "Super Eight" connecting rods are the same.  Cant recall.

 

Which brings me back to my suggestion that you consider just using what you have  now as "dimensional samples",   going for a modern connecting rod already set up for a modern insert.   

 

If you have ANY question about the importance of converting over to a modern "insert" style bearing for a reliable job, capable of handling higher rpm service......,  just ask yourself how many motor manufacturers in the past 60+ years stuck with the poured babbit style.......!

 

 

Edited January 7, 2017 by SaddleRider
reason for edit - i am a lousy typist ! (see edit history)

[Super8]

Hello again SaddleRider,

 

I think that we are in the same logic, especially as the lubricants are much better these days, it is probably the best path. However:

 

- I live in France and It is difficult to find folks/ressources that can help with matching a modern rod that would work. I imagine that due to the long stroke, you would have to find an industrial application or maybe a truck. Do you know an outfit that I could call and would have that capability? I tried Egge with no luck.

 

- Surely, I am not the only one who had to rebuild the bottom end of an early senior. Even the 1935/1936 guys face the same issue. What do they use to rebuild theirs?

 

- Finally, I am surprised that, as this has obviously been a problem for a very long time the Packard parts resellers haven't come up with a reasonable off the shelf solution for this issue.

 

 

[Guest SaddleRider]

For "SUPER EIGHT !

 

My mistake - actually, two mistakes on my part.

 

1)    didn't realize you aren't in the United States!   I have no idea as to whether or not the "hot rod" industry is sufficiently developed in Europe to be able to manufacture custom  engine connecting rods. 

 

Here in the United States there are several companies that do this.    I havnt been involved in this issue for many MANY years, so I  have no way of recommending any of those here in my country.

 

I was TOLD by someone that a company called CARILLO MFG. in San Clemente, Calif. has made a number of connecting rods for pre-war Packards,  and that the customers were satisfied.

 

2)    Sorry I gave you the impression that there were current manufacture connectecting rods from engines made today, that you could substitute.

 

The ONLY substitute would be the con rods from a  '35 - '36 Packard Super Eight ( and possibly the "so-called" Super Eight from '37 - '39 - see my puzzlement above).   I rather doubt if there are many wrecked and/or salvaged pre-war Packards lying around in junk yards any more.....!

 

ONE of the engineering problems that must be dealt with, when using a modern "insert' type connecting rod bearing, is the SHAPE.  Modern connecting rod bearings ( at least current USA practice)    are not "flanged" - only the "mains" are.   The Packard crank-shaft journals were machined for a fillet arrangement so that side-thrust of the rods was handled by the flange part of either the poured bearing for the pre-'35 or the flange built into the insert on the '35 - '39.   People today believe that "flange" was over-kill, for a side-load/thrust problem that is only theoretical.    When fitting inserts to these rods we would braze a bronze "bump" on either side of the rod, then grind it down to take up the space where the "flange" would have been.

Edited January 7, 2017 by SaddleRider (see edit history)

[Super8]

Thanks for the tip on Carrillo SaddleRider. I will look them up. I think that I have a lot more research to do before my engine is running...

[Guest SaddleRider]

I forgot something - a suggestion on pistons.   Should you choose to have pistons made in the United States,  I think you will be fine - I have dealt with all three of the major mfgs down thru the years - never had any problems.    They all seem interested in putting out a serviceable product.

 

You may see some detractors in here claiming this or that one is a bunch of incompetent crooks.  Again, that is not my own experience.  I can tell you about one area, not really relevant to your year,  where people get into trouble.  For late 1937 and later production, Packard used a piston with a steel skirt, which they called "Auto Thermic".    The piston's expansion rate as it heated up in service, was much better controlled, so the factory specs for clearance were "thighter" than is possible with a straight "slug" of aluminum,  ( as would be appropriate in your case ).     I personally prefer fitting pistons "loose as a goose" so there is no "drag" issue as the piston heats up in service.    Seen too many examples of later Packards that wont crank over fast when hot,  owing to piston clearances too tight for the piston used.

 

Let me also suggest you spec. out  THREE ring pistons.   As piston ring technology improved, the number of piston rings required was reduced.  At the time your engine was new, four ring pistons were common - in the earlier days, you would see even FIVE ring pistons.

 

With modern piston ring technology,  three rings is fine - in some applications even two rings work out well.