To Babbit or Not To Babbit vs Inserted??

[1931 flamingo]

To "stir" it up some more. Which head gasket are you using??
Paul in CT

[Tom Wesenberg]

It was the copper gasket.

[sphanna]

Originally Posted by PC/SR

Herm: Were those bearings pressurized? Because without pressure they are not going to be adequately lubricated.

Why would inserts require pressure oil system any more than Babbitt if the clearancees are the same .0015? I would appreciate learning the answer. THX

[PC/SR]

sphanna: The circumferential groove channels the oil around the center or the bearing, not across. Without pressure, the oil is not going to spread far across the bearing. I even have some doubt as to how effective pressure on a Model A rod would be because the oil spurt hole in the top of the big end would not allow much pressure build up.
The A rod had X grooves across the rod cap and across the big end, with the X intersecting at the dipper hole. There is also a short "scooped out" groove at the dipper hole. Thus the oil would be direct to the center of the rod, as well as across it. There was also a V shaped relief at the parting line.
The A mains originally had a spiral groove across the caps and the block side that crossed through the oil hole from the valve chamber. These grooves carried the oil across the main bearings, not around them.
Looks like I got the pics up, thanks Tom. 1. Rod cap. you can see a part of the X in the rod big end. 2 rear main cap. 3 center and front main cap 4. center main block. The rear main block also has a groove through the gravity feed hole that goes across the bearing. Sorry no good pic. Pat

[MikeK]

Originally Posted by sphanna

Why would inserts require pressure oil system any more than Babbitt if the clearancees are the same .0015? I would appreciate learning the answer. THX

They absolutely DO NOT. Anyone who thinks so does not understand the difference between circular machined cast babbitt and the elliptical ramp profile of insert technology. Unlike poured and line bored babbitt, inserts DO NOT present a round hole for the journal to ride in.

The circumferential groove on an insert has NOTHING to do with distributing oil across the width of the bearing. It's function is to channel oil to the parting line.

At the parting line an insert has several thousanths more clearance between the journal and the bearing surface than a circular machined bearing. Still the same 0.0015 in the middle as cast babbitt, but much more at the parting. That's part of the elliptical ramp profile created as the two shells properly 'crush' into position. The oil flows, with no need for pressure other than gravity (mains) or impulse (splash, a few psi at idle with rod dippers) to a wedge shaped trough across 2/3 or more of the width at the parting. Cast babbitt generally has this trough cut in too. This is a reservoir.

In an insert the reservoir across the parting is adjacent to what is called the 'ramp area'. The open ramp area (several thousanths), not present on cast & bored babbitt, traverses the entire width, beyond the ends of that reservoir. That is where the oil is evenly distributed, with no need for a pump, across the entire width of the bearing. The circumferential groove has nothing to do with spreading oil across the width!

Rotational force from the journal strongly compresses the oil molecules toward the apogee of the bearing because of the exaggerated elliptical 'ramp'. If you want to understand those forces, look up and study: London dispersion force, quantum theory of dispersion, and Van-der-waals forces. A running elliptical insert rides up and runs on a much thicker oil film than a circular cast bearing. That is one of several reasons you get 50,000+ miles on inserts with only 0.001 babbitt and have virtually no wear, eliminating the need for shim adjustment. As I stated in a post above, if you do the math those forces provide an extreme self-pressurization of the oil at running speed, creating the much thicker film than you get from the old scrape and smear oil distribution of circular machined and spiral grooved cast babbitt.

So why are modern engines pressurized? The internal friction of dragging oil molecules across each other creates heat. As you increase linear speed (a function of RPM and journal diameter, BOTH larger in modern engines) the rate of heat production increases. At some point the base metal cannot conduct that heat away fast enough to keep the bearing surface temperature lower than the vaporization temperature of the oil. To exacerbate the problem, the shorter the oil HC chains (lighter weight oil) the lower the vapor point.

Modern engines use light weight oils because it takes less horsepower to bulk move them. One trip down the interstate on-ramp with bearings having several times the linear surface velocity of an "A" would bring the light oil in the bearings to vapor, which has near zero lube properties and will not support the journal up off the bearing material.

Theoretically, you only need one drop of oil in a bearing, it will recirculate forever. But it will also get hot. In an "A" the oil leakage out the sides (cast or inserts) under gravity or splash feed is more than adequate to keep the oil below vaporization. In a modern engine you also need to physically force it through at a faster rate to effect sufficient cooling. THIS is where the circumferential groove, necessary only in the feed half of the bearing, comes into play. In a pressure app, it permits much of the feed oil to push sideways and out, cooling the bearing surface. That heat problem is also why you find oil coolers on trucks and race cars.

ANY application that will run cast babbitt without pressure oil feed will also run inserts without pressure feed. Of course, ANY bearing job that is improperly done, cast or insert, will fail.

With inserts, it is CRITICAL to line bore the shell holes the proper size to effect shell crush. 0.002 too large will RUIN the block for inserts. The shells will not crush into the proper elliptical ramp profile and will be round like cast babbitt. As shade tree rebuilders quit babbitt and start using inserts, failures will begin to appear with increasing frequency. Why? Those sloppy, flexy, flimsy boring bar jigs that were fine for soft babbitt will be adapted to cut the insert bores, INACCURATELY. Very close is good enough for cast babbitt, you play with the shims. "Close" will ruin a block bored for inserts. If a rebuilder's line boring setup and technique/skill can't hold a couple tenths tolerance, walk away.

If all this scares you and you want cast babbitt, I have a whole string of Q's for the babbitteer (is that a word??) If you want to read some of what I know about babbitt, read my posts #2 & #12 in this thread: LINK The Q's are in #12. Done properly, cast babbitt is just fine in an "A".

[Rex_A_Lott]

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Thanks MikeK. That was a lot to digest at 5am, before I'd had my first pot of coffee...I had to go back and re-read it, and its still mostly over my head, but it gives some things to think about.

[James Rogers]

Excellent dissertation and, all correct.

[Gord. B by the bay]

Very helpfull Mike many thanks for sharing Gord. B by the bay

[Kohnke Rebabbitting]

Well Mike, I have 3500.00 dollars of babbitt in the tinning pot, and 6000.00 dollars in the Pouring pot, and the only Gas around the the pots for 44 years, has come from the L.P. tank, and Me!

So with out a bad bearing in 44 years, with at least 30,000 spun poured, just in Model A Ford rods, not counting all other cars, tractors Ect., I just for the life of me, can't figure out what I am doing wrong?

Of the bearings that have been changed over to inserts in the last 10 years, have now had there bearing inserts that they used Obsoleted completely, or in certain sizes. Say the insert you used is no longer available, then what, happens every day, companies go broke, People Die, Not enough call for an insert Ect. May be the cranks wore .002, and still round, and no bigger sizes, then what? Nothing is made for ever!

Race cars never had trouble with babbitt bearings, or any of the other cars. The only time for bearing trouble, is when the engines got wore out or mistreated, and I don't think your inserts would act any different, may be not even as good!

My first questions to anyone with a babbitt pot are what alloy, how do you degas it, and what do you use as a grain refiner prior to pour, and how long do you hold it after the final degas and grain refinement? The answer to the last few Q's is inevitably "Huh?". That's why I will always use inserts and NEVER have anyone who does model A work do a babbitt job for anything I own. If you want to hear "Huh?" again, ask what their protocol is to degas, pig, and de-skull the melting pot between runs, and at what time interval?

As far as I am concerned, "Huh" is an Appropriate answer! You may have to do what you are suggesting in a foundry setting, with Aluminum Ect. But the way I look at is, in something doesn't work, then you have to Question WHY?
But How Do you fix something that works?



My first questions to anyone with a babbitt pot are what alloy, how do you degas it, and what do you use as a grain refiner prior to pour, and how long do you hold it after the final degas and grain refinement? The answer to the last few Q's is inevitably "Huh?". That's why I will always use inserts and NEVER have anyone who does model A work do a babbitt job for anything I own. If you want to hear "Huh?" again, ask what their protocol is to degas, pig, and de-skull the melting pot between runs, and at what time interval?


No Where, In any book, or artical on rebabbitting, have I every read anything to do with what you are talking about in the level of babbitt, past the ore stage. SO, I said to my self, "Hay Self" Why don't you call the the foundrys that put the mix togather, so I did, I read them your paragraph, and asked them if it is something to look into, you will never guess what the first guy said, well maybe you did, he said "Huh? So according to the first guy, and they are mixing it, it is nothing I would have to be concerned about, as what I work with, is way after the stage you are talking about, as the babbitt is already refined. And as far as holes in the babbitt, and wrinkles, Ect. That is corected by the Babbitter. With all this said, there is no two bearings, and or Jigs the will pour alike, Heavy bearings, Thin bearings, Leakey bearings Ect. The only secret that I know of Hidden in a good bearing, is all Temps, Time, and Heat retention. And you have to know what to do to correct it.

I do feel sorry for James, agreeing with Mike, as he now knows you can't pour a Model A Block like he has been doing, and coming to terms with all the machinery, and testing equipment he will have to put in to do a Model A block right, unless he has it?



That's why I will always use inserts and NEVER have anyone who does model A work do a babbitt job for anything I own.



Thats about what I thought Mike, You know all about pouring babbitt, but can't do it your self, thats all right, you arn't the only one on here like that.



But, I still feel sorry for James.

[BRENT in 10-uh-C]

Originally Posted by Kohnke Rebabbitting

But, I still feel sorry for James.

Herm, what you trying to imply?

.

[Kohnke Rebabbitting]

Join Date: May 2010
Location: South Florida
Posts: 2,834

The answer to the last few Q's is inevitably "Huh?". That's why I will always use inserts and NEVER have anyone who does model A work do a babbitt job for anything I own. If you want to hear "Huh?" again, ask what their protocol is to degas, pig, and de-skull the melting pot between runs, and at what time interval?



Re: Engine rebuild cost
$2000- $5000 Check with www.schwalms.com Schwalm's/Ora Landis (Babbitted Bearings)(Pennsylvania)


Sounds like a contradiction in terms, or ideas to me Mike! Or Schwalms meets all your babbitt processing ideas. Maybe you could ask them to show us all the steps you have to take, to show how we should be doing it, or unless it a secret. I know I am an Inquiring Mind!

[Kohnke Rebabbitting]

Originally Posted by BRENT in 10-uh-C

Herm, what you trying to imply?

.

I am not implying any thing, did you for get how to comprehend? Read the Post!

[hardtimes]

Wow, you guys are thought provoking, informative and entertaining! Made me run (well hobble) right out to examine block/rods/stuff in the shed to check on your info and learn further!
Herm, Mike, PC and others...thanks for the instruction and entertainment (hmm, pascal ? must be insider stuff.

[James Rogers]

I don't see any implication, Herm thinks me an IDIOT. This has become very obvious in the last months so I just don't reply to any of his posts no matter what. I guess I just don't know what I am doing according to the GOD OF BABBITT.

Last I have to say!

[Kohnke Rebabbitting]

I do feel sorry for James, agreeing with Mike, as he now knows you can't pour a Model A Block like he has been doing, and coming to terms with all the machinery, and testing equipment he will have to put in to do a Model A block right, unless he has it?

Well, this is for your acting Mommy "Brent", read this one over, and over, or just wait until morning, when the "Bud" is worn off!

Originally Posted by James Rogers

I don't see any implication, Herm thinks me an IDIOT. This has become very obvious in the last months so I just don't reply to any of his posts no matter what. I guess I just don't know what I am doing according to the GOD OF BABBITT.

Last I have to say!

No place that I know of that I have called you an "Idiot" but when I, don't agree with any statement, idea, supposed fact from anybody, you will here a different opinion, and as many times as I have to say it. If I am wrong, SHOW ME. If you want me to agree with you, start saying things I agree with!

Oh, and James, my title in not "God of Babbitt" it is Babbitt God. You only use God of Babbitt when you are an Apprentice!

It is just like the Guy who had a job baiting hooks with fish parts, for rich people, down at the Wharf. He worked 2 years for his boss as an Apprentice Baiter, then one day after 2 years, his Boss gave him his Diploma, showing that he had graduated to being a Master.......

[MikeK]

Originally Posted by Kohnke Rebabbitting

Well Mike, . . . and the only Gas around the the pots for 44 years, has come from the L.P. tank, and Me!

You sure let a lot of it go in this thread!
I'm done here in this thread too. Moving on.

[Kohnke Rebabbitting]

Originally Posted by MikeK

You sure let a lot of it go in this thread!
I'm done here in this thread too. Moving on.

Mike, It sounds like the pot calling the kettle black, You being from the Windy City, and all!

[1931 flamingo]

FEEL THE LOVE...................

Paul in CT