The Stovebolt Site Forums The Shop Area Engine Shop "Babbitt fails gracefully"

I've read this statement or something like it a few times. I guess the general thought is as babbitt wears down and clearances increase, the lower oil pressure and/or noise give some warning, and time to address.....as opposed to spinning a bearing and taking the engine out of service immediately.

Thoughts?

Try adjusting the clearance on a steel-backed bearing with less than 1/16" of soft bearing material sometime. By the time the oil pressure drops, and/or the noise level increases, it's too late to even replace the bearing in most cases- - - -there's also crankshaft wear and/or damage. Also, Babbit can imbed a lot more foreign material without totally destroying the bearing layer.

Since none of the full-pressure stovebolt engines ran Babbit rods, oil pressure really isn't a good indicator of bearing clearance. The pressure-lubed bearings such as main and cam bearings are all thinwall steel backed bearings. Model T and Model A engines are a different breed of cat, with poured and line-bored bearings in those locations.
Jerry

So would you consider this phrase "horse feathers" as it would pertain to the 216?

JW51,

Here's a discussion on converting poured bearings to inserts.

https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=441248

This process has been around for decades. I read about it in the VCCA monthly magazine, Generator and Distributor, in the early 1980s. I wish I'd known about it when I restored my '36 Chevy PU in the 1970s.

The challenge would be in finding a competent machinist to do it. After moving from a big urban area to a rural area I can see that there are definitely different standards of quality in the urban versus rural communities.

Yeah, I'm aware of the insert bearing process with 216. And if babbitt was "better" overall, there would be no such process.

But as with most things in life, there are always tradeoffs. Thought maybe this would spur some dialogue about "unsung" advantages of babbitt.

Example: part of me is intrigued by the ability to remove shims in the connecting rods. Perhaps that is an "advantage" or perhaps it's a just a band aid to account for the material wearing faster. I'm too young to have any first hand experience with one vs the other, but always eager to hear from the more...ahem...."experienced" members of the forum.

JW51,

I would like to encourage you to do some independent research rather than relying on self proclaimed "experts". I'm no "expert", just a highly interested amateur with an interest in engines since I was a teenager in the 1950s. Using my quest for brake upgrade information as an example you can see how a narrow versus wider search compare:

https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/1196340/2/Huck_brake_dual_MC_upgrade.html

http://www.chevytalk.org/fusionbb/showtopic.php?tid/341390/

If I were restoring a poured bearing engine today I would give serious consideration to an insert bearing conversion. I would look for a machine shop that specializes in that conversion and has good customer reviews. In my youth I had a neighbor with an engine shop and he was on contract with an obsolete Ford parts supplier. He had done extensive research and made some interesting discoveries that allowed him to streamline his antique engine rebuilding process and keep costs down. One example that I specifically remember is that he used readily available, inexpensive Oldsmobile pistons in Model A Ford engines.

Also, it helps to find the shop that will actually be doing the work. For example when I was doing my restoration in the 1970s I was in Egge Machine for something. There I saw a reground camshaft in a carton labelled Tomaedur Engine Company. Egge was charging $49 (1970s dollars) to have that camshaft reground. I took 2 camshaft cores directly to Tomadeur. The shop foreman looked at them both, picked out the better of the 2 and reground it while I waited. That took about 10 minutes and he charged me $7. That shows the markup when someone says "I can send it out". We don't need to send it out. We can take it there ourselves. By the way, that camshaft is still doing great nearly 40 years later.

JW- - - -if you'd like to hear about some real world experience from the days when Babbit rods were in everyday use, send me a PM. I don't need to search the whole internet to give you plenty of information, but I'm tired of getting into whizzing contests.
Jerry

Yar:

Actually, I'm more or less doing what you describe. I had read the statement that is the title of this thread in a few different places on the internets. Rather than just accept it as true, thought some of the very knowledgable folks here might offer some insight.

Don't have a dog in the fight. I have no plans to rebuild a stovebolt in the immediate future. I just like to glean as much as I can. Another decade or two down the road, these engines will be fewer, and so will the folks who know anything about them.

For a great visual of where we get poured connecting rod bearings from, watch "The Train" (Frankenheimer) with Burt Lancaster casting and scraping a new bearing, then swinging the connecting rod into place using an overhead crane.
It's a steam locomotive.

JW51

"Don't have a dog in the fight. I have no plans to rebuild a stovebolt in the immediate future. I just like to glean as much as I can."

I know what you mean. When I did the 3.55 rear gear conversion on my '36 pickup both the VCCA and the 1936 Chevy Owners' Forum asked me to do a write up with pictures. I don't have the computer skills to post an illustrated story but I sent it to them and they both posted it:

http://vcca.org/forum/ubbthreads.php/topics/334876/1936_Chevy_3.55_rear_gear_conv

Several guys contacted me saying they wouldn't do such a conversion but they enjoyed reading about it. That's how I felt after reading about the insert bearing conversion. It was too late for me because my engine had just been completed the old fashioned way but it was still a fun read.

No matter the subject, whether in personal life, work or hobby stuff, there is always new and interesting stuff to learn. Right now, at age 72, I'm learning new stuff about brakes doing a tandem master cylinder conversion on my '36.

First, you must realize that modern bearings STILL USE BABBITT MATERIAL!!! But the process of POURED babbitt using a rough form then machined vs more of a very thin 'plated' bearing which required minimum finishing.

Insert bearings were invented to take out all the work needed to repair a babbitt engine, and increase tolerances. Babbitt may last longer, or 'wear more gracefully' but the time and cost involved (even back in the day) would be significantly higher than inserts. Also motors that use babbitt bearing gave nowhere near the performance of later insert bearings.
For my 235 a set of bearings is less than $100. That's not even an hours time at a good machine shop.

"Babbit can imbed a lot more foreign material without totally destroying the bearing layer."

Well oil filters not being a big deal back then they yes, you will have a lot more crud in the oil as there was no filtering. But in the 40's engines starting getting oil filters and detergent motor oils so the amount of 'crud' would be significantly reduced. Also PCV systems taking a lot of moisture out of the oil decreased sludge. So thick babbitt bearings were really not needed.

If you read the service manuals and look at the amount of work to rebuild a babbitt bearing motor vs an insert motor its obvious that inserts, while not having ALL the supposed 'benefits' (again, this is more emotional than scientific, inserts solve every problem babbitts have) is a significant step forward in reliability and cost.

Is one 'better' than the other? Well, the purest will say that if the motor was poured babbit, then it should ALWAYS be poured. But for the cost of getting that work done vs 'failing gracefully' that makes no sense. For the cost of poured babbitting you could change your inserts every 50,000 miles, never see any significant wear, and still cost less than a babbitted motor getting ONE rebuild.

Chevy rods did not use poured bearings. The process was known as "centrifugal casting" and produced a thinner, more uniform layer of bearing material that was far superior to poured Babbit.

Opinions are like "belly buttons" (and other bodily orfices). Everybody's got one, and some are pretty stinky.
Jerry