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How do plan to drive the car????
What about converting to insert bearings????

see this link about the babbit vs insert conversion debate.

http://forums.aaca.org/f134/driving-speed-32-packard-273862.html

JP:

No. Wanted an open Packard to restore, which is what I am doing with the 640 phaeton. Have moved to Colorado where I have a much larger shop.

Thanks,

Jim

Plan to do touring in the car as well as the usual weekend driving. Do you have a source for bearing inserts?

Thanks,

Jim Wayman

I have no knowledge of any source. I am interested in following the topic as it arises quite often. Those currently in the rebuild proccess mite know of sources.

When considering insert conversions don't forget the 1935 and up rods used flanged insert rod bearings, and the 34 and back were also babbitted on the side faces of the big end to obtain the correct side-play clearance between the crank cheeks. Brazing "nubs" on the sides of the rods and filing or machining to get the correct side-play has been done and apparently successfully, but has never sounded like a great idea to me.

CCCA had some good technical articles on this type of conversion some years back. Send me a PM with your email and Ill send you a copy.

Converting to inserts is a very complex process. There is a lot of machining involved. I converted mine about 2 years ago. I did not convert because of fear about babbited rods, but because my factory inserts had been re-babbited at some point, and were suffering from massive failure. My personal research and discussions with very knowledgeable individuals led me to the conversion to modern inserts. I agree with O-D on the blobs of brass being filed not sounding all that good. Mine were welded full circle and machined to size for factory specified connecting rod side clearance. This ensures the rod will not knock from excess side play, and also ensures the proper amount of oil can push past the side clearance to stay cool by allowing new oil to enter the clearance, yet ensure enough oil remains in the working clearance of the rod to maintain an adequate lubrication boundary layer.

Many people involved with Packards said this was a tried and true method. Some thought I should have just converted to babbit. One fellow who has had about 20, maybe 30 different user accounts on this, and the AACA site gave me no end of grief, basically predicting doom and apocalyptic failure. The car presently runs fine.

At the time, these were my only options because the bearings had not been available for years. At present time, to the good fortune of 320 owners, David Schumacher had these bearings reproduced. Had that been an option when my situation arose, I am almost sure I would have used those bearings due to the intense amount of work in converting.

Many, including O-D, Tbirdman and others here that obviously put responsibly driven miles on their cars report little issue with babbited rods. In the end, you will have to gather the opinions of those who have had experience in this area and decide.

The one thing that is very surprising to me is how common this question / situation seems to be. I am very surprised how little is really known about what bearings interchange, and who is tooled up to do the conversion. It always seems like a new and unexplored frontier (with the exception of some known info such as the article O-D has mentioned).

I will follow your thread with interest, as I am interested to see what innovative fixes fellow Packard owners might employ in order to stay on the road.

Best of luck,
Jim

39Super8 wrote:
"I did not convert because of fear about babbited rods, but because my factory inserts had been re-babbited at some point, and were suffering from massive failure. ....
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At the time, these were my only options because the bearings had not been available for years. At present time, to the good fortune of 320 owners, David Schumacher had these bearings reproduced. Had that been an option when my situation arose, I am almost sure I would have used those bearings due to the intense amount of work in converting."

ok. What insert bearing did u convert to at the time???

If years back I had wanted to convert my 34 Eight (320 engine) to inserts, I'd never consider the remachining of the rod, notching the rod bolts, and brazing the end-gap stops on the flange side, I'd have gone shopping for a set of 1935 and up rods but of course this has only become an option since those flanged bearings have again become available. Even in the 60s and 70s these bearings were pretty much unavailable.

Now lets brace ourselves, Twunk Rack will probably come along and remind us how stupid and ignorant we are. Remember, he who said no car with babbit bearings should be driven any further than on and off a trailer? I wonder how all those Model A Fords, Chevies and Hudsons into the early 50s, etc., made it across the US so many times? The answer is they drove sensibly within the limitations of the technology.

Conversion to inserts makes any future bearing service alot cheaper and easier than continuation of babbit. However, cost and inconvenience of such a conversion mite not offset the future benefits of conversion. Perhaps it depends on individual owner demand.

On the other hand, there are other potential limitations for those that choose to convert to inserts for the purpose of sustained higher engine rpm/demand. That being strength of rods originaly designed for babbit.

i'm not familiar enuf with the Packard streight 8 to determine if the rods are suitable for sustained increase of engine rpm to say 3000 - 3200 rpm.

So conversion to inserts makes future maintenance cheaper and easier but mite not allow for increased performance demand from the engine due to other parts such as rods that are not strong enuf.