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1920's Rod bearings


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I for got to bring up the "method", some use to set cranks. Use it if you want, but what it does among other things, is take the polished finished off the crank, and bearings, some rebuilder tried so hard to put there. One rebuilder left a little in the engines thinking it was going to break them in, and what it done in took the engine out in less then 5 miles, and I mean everything. Do not leave any excess in your motors. Herm.

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  • 5 weeks later...
Guest Al Brass
The original poster said these were insert bearings. I'd really be curious to know the make of car (or maker of the engine if different), as insert bearings in the 20s would be uncommon.

My '15 Buick has white metal (babbit) inserts that fit exactly like a regular shell. To me, this is pretty cheap, a bronze backing would make it much stronger. I suspect Buick would have used the same idea quite a few years before '15 too.

Al

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  • 2 weeks later...
My '15 Buick has white metal (babbit) inserts that fit exactly like a regular shell. To me, this is pretty cheap, a bronze backing would make it much stronger. I suspect Buick would have used the same idea quite a few years before '15 too.

Al

When the Majority of the car companies, and other engines builders went to inserts, it was not necessarily better bearings, but it did save bearing builders, and all engine Manufactures millions of dollars. All the shipping back, and forth to the Rod babbitters, all built storage, having to shelf all the different brands, and then different sizes, parts Housing Ect.

Rod inserts should NOT be repoured, in any Rod. Inserts in main bearings, (talking a Good Job) is fine, as they do not get the shock that a rod gets. When the inserts are New, say Bronze, the out side, and inside of the insert, is machined, and the rod is bored, or honed to a size to be a almost 100% fit to the Rod. BUT, when you repour, the insert distorts, and will never will be a fit to the rod required to get the fit you need to make the bearing last the rebuild, and it should, and longer.

From the time we went into bussiness,( 44 Years ago) we have taken insert rods, and poured them solid. It will make a better bearing any way, and the Babbitt tinned to the rod, does not allow oil to be between the Babbitt, and the rod, which allows a better heat transfer, as OIL is NOT a GOOD CONDUCTOR!

If you have a shimmed bearing in a engine, when you have a total of .006 thousandths of shims off each side, your bearing has pretty much run out of it's usefulness, especially on a Oil Pressure Bearing. The reason being, is when say a 2 inch rod hole has .006 thousand shims out, even if the rod can be set to .002 thousandths clearance, top and bottom, the sides still have .006 thousandths clearance on both sides. Yes, you will have low, to No oil pressure, BUT the worst thing, and if the mains have to be taken up like that also, is that the oil that will be lost because of it, the rods pick up the extra oil and through it to the pistions, and you have an oil burner!

There are a lot of poured babbitt rods in the the 20's, but being we pour everything, I would say it is about 50, 50 between the two!

Now the Bluing of a bearing. Bluing a bearing is all right, if you have alot to Hog out from wear, as it is NOT useful to FINE, or FINISH scrapping. The best way is snug the bearing on the shaft, so you can still turn it with a heavy drag, and it will leave a dark, or rub mark. That is what you take off, and it will only be about say .00020 tenths at a time. DO NOT put your rod on the crank by it's self, as it will most likely change when you put the piston on, and put it in the cylinder. So leave the rings off, and put the pistons on, and in the cylinder.

That brings us to Rod alignment, before any rod scrapping, take your rods to some shop that knows how to align rods, for Twist, Bend , and OFF SET, especially if new, as many guys that pour babbitt, don't, and or won't, or don't know how to align rods. Many times when asked if they align rods, the excuse is, Oh the machine bores them straight. The truth is, there is not a machine build, past, or present that will be good enough to put in an engine with out checking alignment of the rod.

The Pictures are of, Twist, Bend, and Off Set. Thanks Herm.

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Rod inserts should NOT be repoured, in any rod. Inserts in main bearings, (talking a Good Job) is fine, as they do not get the shock that a rod gets. When the inserts are new, say bronze, the out side, and inside of the insert, is machined, and the rod is bored, or honed to a size to be a almost 100% fit to the Rod. BUT, when you repour, the insert distorts, and will never will be a fit to the rod required to get the fit you need to make the bearing last the rebuild, and it should, and longer.

From the time we went into bussiness,( 44 Years ago) we have taken insert rods, and poured them solid. It will make a better bearing any way, and the Babbitt tinned to the rod, does not allow oil to be between the Babbitt, and the rod, which allows a better heat transfer, as OIL is NOT a GOOD CONDUCTOR!

Herman's advice is very helpful for people, but I have some concern about this extract, on the basis of history and physics.

The very first ultra-thin white metal bearings were a contribution of American auto racing. When the displacement limit was reduced from 300 cubic inches to 183 for the 1920 season, the increased rpm revealed a problem with the durability of Duesenberg's big end bearings. Not only did the thick layer of whitemetal break down with the high speed and loading, but they also found that bronze shells softened to plasticity at a temperature little higher.

Those Duesenberg straight eights with only three main bearings needed a very high oil pressure to ensure fair supply to the most distant big end bearings, and also a fairly minimal oil film thickness on the conrod journals for the same reason.

Now while oil has a low conductivity of heat compared to metals, the mass flow of oil through the crankshaft bearings has a vital role in cooling both them, and the engine as a whole. If those Duesenberg engines had been designed with five main bearings instead of just three, they might have run much greater clearances for cooling and Duesenbergs may not have needed to invent those very thin, direct-lined bearings so quickly.

I have just measured the thickness of whitemetal in a 1923 A Model Duesenberg conrod for you at 25 to 30 thousandths of an inch. This is thick compared to the embeddable thickness of either babbit whitemetal or copper-lead alloy of modern bimetal strip bearings.

I find it hard to understand how applying the minimal heat from a gas torch to remove old babbit from a bronze shell could shrink or distort it so there is no tight contact and good heat transfer between the shell and the bore of the conrod. If the outside diameter of a bearing shell was one thousandth of an inch greater than the bore it had to fit, then the circumference would be about three thou greater. When we assembled reconditioned Leyland or GMC 6-71 diesel engines from WW2 army surplus tanks, if the clearance between rod and cap on one side with the bolt loosened was less than 6 thou we would have the conrod bore re-sized. Bronze shells are plastic and slightly compressible, and they should have some nip-fit.

I find it hard to agree that babbit-lined bronze shells, properly designed and fitted are unreliable, even in racing. Lancia Aurelias only changed to Vandervell steel strip bearings in 1954, and they did have longer service life. Nevertheless: Lancia ran a team of the first two-door hardtop Aurelia B20 GTs in the 1951 Mille Miglia. This was a gruelling circuit race of 1000 miles on a road course in Italy. The 1750cc V6 developed about 75 bhp at around 5000rpm, and the car's maximum speeed was about 100mph. At 850 miles, Bracco's B20 was less than 3 minutes behind the leading 4.2 litre V12 Ferrari of Villoresi, which had a top speed of 160mph. Unfortunately at that point the torrential rain stopped and the roads were straighter; so the Ferrari was able to extend its winning margin to 20 minutes in the last 150 miles.

Diecast whitemetal bearings (as removeable inserts) are fraught with risk. Royce Fullard still has a 1920 Lancia Kappa which was their family car from near new. Eventually he and his brothers Geoff and Alf made replacement babbited bronze shells and the Kappa gave no more trouble. Geoff is a very fine engineer. ( Vincenzo Lancia made very few engineering blunders in the design of his cars). Some Rutenber engines about 1920 also had diecast replaceable whitemetal crankshaft bearing inserts. You can even see the diecast name of the manufacturer in the oil groove of the insert. There was a job-lot of these engines sold to the Australian Six car company in Sydney, and they had a lot of trouble with them. (The spelling probably should have been "Rottenber").

Herman's photos of his work are beautiful, and these thick-cast bearings are doubtless excellent for weekend tours and loading on a trailer. The ultimate durability of a poured bearing, or even an aircraft grade sprayed one for that matter, is critically dependant on the thickness of the babbit because of the plasticity of the tin-based alloy. I would not choose to race thick bearings in competition, or drive across the continent.

The English Hoyt company have produced a range of bearing alloys for all purposes for very many decades, and their Book of the Lined Bearing is an excellent instruction and reference. I have never yet needed to do so, but they recommend re-lining copper-lead bearing shells with babbit.

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Rod inserts should NOT be repoured, in any rod. Inserts in main bearings, (talking a Good Job) is fine, as they do not get the shock that a rod gets. When the inserts are new, say bronze, the out side, and inside of the insert, is machined, and the rod is bored, or honed to a size to be a almost 100% fit to the Rod. BUT, when you repour, the insert distorts, and will never will be a fit to the rod required to get the fit you need to make the bearing last the rebuild, and it should, and longer.

From the time we went into bussiness,( 44 Years ago) we have taken insert rods, and poured them solid. It will make a better bearing any way, and the Babbitt tinned to the rod, does not allow oil to be between the Babbitt, and the rod, which allows a better heat transfer, as OIL is NOT a GOOD CONDUCTOR!

Herman's advice is very helpful for people, but I have some concern about this extract, on the basis of history and physics.

The very first ultra-thin white metal bearings were a contribution of American auto racing. When the displacement limit was reduced from 300 cubic inches to 183 for the 1920 season, the increased rpm revealed a problem with the durability of Duesenberg's big end bearings. Not only did the thick layer of whitemetal break down with the high speed and loading, but they also found that bronze shells softened to plasticity at a temperature little higher.

Those Duesenberg straight eights with only three main bearings needed a very high oil pressure to ensure fair supply to the most distant big end bearings, and also a fairly minimal oil film thickness on the conrod journals for the same reason.

Now while oil has a low conductivity of heat compared to metals, the mass flow of oil through the crankshaft bearings has a vital role in cooling both them, and the engine as a whole. If those Duesenberg engines had been designed with five main bearings instead of just three, they might have run much greater clearances for cooling and Duesenbergs may not have needed to invent those very thin, direct-lined bearings so quickly.

I have just measured the thickness of whitemetal in a 1923 A Model Duesenberg conrod for you at 25 to 30 thousandths of an inch. This is thick compared to the embeddable thickness of either babbit whitemetal or copper-lead alloy of modern bimetal strip bearings.

I find it hard to understand how applying the minimal heat from a gas torch to remove old babbit from a bronze shell could shrink or distort it so there is no tight contact and good heat transfer between the shell and the bore of the conrod. If the outside diameter of a bearing shell was one thousandth of an inch greater than the bore it had to fit, then the circumference would be about three thou greater. When we assembled reconditioned Leyland or GMC 6-71 diesel engines from WW2 army surplus tanks, if the clearance between rod and cap on one side with the bolt loosened was less than 6 thou we would have the conrod bore re-sized. Bronze shells are plastic and slightly compressible, and they should have some nip-fit.

I find it hard to agree that babbit-lined bronze shells, properly designed and fitted are unreliable, even in racing. Lancia Aurelias only changed to Vandervell steel strip bearings in 1954, and they did have longer service life. Nevertheless: Lancia ran a team of the first two-door hardtop Aurelia B20 GTs in the 1951 Mille Miglia. This was a gruelling circuit race of 1000 miles on a road course in Italy. The 1750cc V6 developed about 75 bhp at around 5000rpm, and the car's maximum speeed was about 100mph. At 850 miles, Bracco's B20 was less than 3 minutes behind the leading 4.2 litre V12 Ferrari of Villoresi, which had a top speed of 160mph. Unfortunately at that point the torrential rain stopped and the roads were straighter; so the Ferrari was able to extend its winning margin to 20 minutes in the last 150 miles.

Diecast whitemetal bearings (as removeable inserts) are fraught with risk. Royce Fullard still has a 1920 Lancia Kappa which was their family car from near new. Eventually he and his brothers Geoff and Alf made replacement babbited bronze shells and the Kappa gave no more trouble. Geoff is a very fine engineer. ( Vincenzo Lancia made very few engineering blunders in the design of his cars). Some Rutenber engines about 1920 also had diecast replaceable whitemetal crankshaft bearing inserts. You can even see the diecast name of the manufacturer in the oil groove of the insert. There was a job-lot of these engines sold to the Australian Six car company in Sydney, and they had a lot of trouble with them. (The spelling probably should have been "Rottenber").

Herman's photos of his work are beautiful, and these thick-cast bearings are doubtless excellent for weekend tours and loading on a trailer. The ultimate durability of a poured bearing, or even an aircraft grade sprayed one for that matter, is critically dependant on the thickness of the babbit because of the plasticity of the tin-based alloy. I would not choose to race thick bearings in competition, or drive across the continent.

The English Hoyt company have produced a range of bearing alloys for all purposes for very many decades, and their Book of the Lined Bearing is an excellent instruction and reference. I have never yet needed to do so, but they recommend re-lining copper-lead bearing shells with babbit.

Ivan, some of what you say can be true, BUT you are starting with the wrong premise that you know the process for rebuilding bearings properly. I will start with, in 44 years, we have poured over 30,000 Spun Poured just in Model T Ford rods alone, and that was only about 1 percent of our bearing business, as we rebuild all other cars, tractors, Ect. (( We Have Never Had A Bad Bearing EVER!!! We had a set of Rods, and Main Bearings, in a Blue Plymouth Coupe in last summers China to France race, and no Motor problems, when they got the car back to the U.S., they pulled the pan and bearings, check the clearances, ALL were all right, and it will be raced again in a long race on the west cost, this coming summer. The car was run wide open the whole race at 50 mile an hour, and it had a low speed rear end. Look it up on the internet, many pictures, and Log each day.

(Quote) I find it hard to understand how applying the minimal heat from a gas torch to remove old babbit from a bronze shell could shrink or distort it so there is no tight contact.( End Quote)

The reason you might find that hard to understand, is that is not the way it is done! The old babbitt is melted out, NOT with Minimai heat, but with a controled heat of 610 to 640, 650 will burn the tinning off, , under 610 will not tin a bearing properly, it may have the appearance of it, But it is not,as it would be to cold. Distortion does not come from the melting out, of old babbitt, or retinning of the shell again, but it comes from the bearing being repoured, and the cooling process. The ends of the shell will pull towards each other, and it has to be spread again, and there is no way you can get 100 % contact again, and where the back of the insert does not contact the rod, say the size of the end of your little finger, when the crank applys its pressure, the insert pushes in, and out to its limits, and then the babbitt will fracture. The same thing on the mains, does not bother, as the stress is different. Just about 100% of the time, if a new bearing fails, it is the workmenship!!! Just like a modern insert, when you have failure, you can tell what caused it, it is the same for Babbitt. Babbitt gets a bad rap all the time, a Guy, or machine shop will get some pouring jigs, and put out a sign, that says Rebabbitting Here, when it takes years to learn to rebuild a bearing, and not have it fail from Bad workmenship, so the babbitt fails, and the first thing that happens, is they blame the babbitt. If you had a new tire, and had a flat, and you had it fixed, and the Repairman didn't put enough cement on the patch, and it leaked, do you blame the tire. ???

A prime example of bad workmanship can be seen on countless Home You-Tube Videos, of Guys showing how to pour a Babbitt Bearing. I have watched every one, and have not seen one done right yet. I watched one last night, a Man showing a poured bearing, it was a Bronze shell, he as you said was using a small low heat torch, melted out the old babbitt, poured the bearing, He DID NOT clean the carbon, or even the patina off the Bronze!! Boys, Nothing Sticks To Dirt!!! So then he shows how you have to melt and solder the ends of the bearings to weld the holes shut, because the babbitt did not stick. Also some videos show, after pouring a bearing, they melt the inside of the bearing because they have wrinkles, Blow Holes, Slag, Ect. in their pouring, the bearings are doomed.

But they get away with it long enough some times, to get out of warranty. If a given bearing will blow up in say a 1000 miles, and he only drives the car 50.00 miles a year, or what ever, it will take 20 years before he finds out how bad he got screwed!!!

From the 20's on up in late 40's, and early 50's , all race cars had babbitt bearings, and there was never noted Babbitt bearing problems. All the cars that were made, had babbitt bearings, and had no trouble, unless they were neglected, as cranks flat, low oil, oil not changed. Just like the Model T Ford, and like cars, the People that cussed them were the people that drove them when they were wore out, because they couldn't afford any thing else.

The last thing Ivan, we don't build bearings that have to be used in Trailer Queens. The best advice I can give you Ivan, is there is a difference in Doctors. Also a lot of miss information being dumped on the Guys that are looking for Facts. Thanks Herm.

First Picture

Our Race Car, Barney Kloepfer's Car built in about 1926, Driven by Erine Triplett, Second place in the Pacific Cosast AAA Cars-1930

Second Picture

Gulliven, and RAJO design, Two stick, Hemi Combustion Chamber, Model T Block, 14 to 1 Compression, all BABBITT!!!

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Edited by herm111 (see edit history)
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Guest PackardV8

Great thread and great posts. But instead of re-babbiting why not machine the block and/or rods for a current production and easily obtainable INSERT bearing???

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Great thread and great posts. But instead of re-babbiting why not machine the block and/or rods for a current production and easily obtainable INSERT bearing???

Many engine systems do not lend them selves to inserts. Many times when you very from babbitt, there are other things to take into consideration, such as availably of the inserts that you changed over to, or in the size you need to go, or in the case of spinning an insert, is there another size that would fit if that would happen. Inserts require a very clean oil system, as they are not very for giving, as dirt goes.

In the last 10 years at least, there has been a shortage of Rebabbitters that can build a babbitt bearing that will last, so some of the machine shops have had to try something else, as there is no profit in come backs. I know many that had their babbitt let loose, so they went to inserts, because they didn't have the ability to use Babbitt. Rebabbitters, are like Drummers, there are only two kinds, and that is Good ones, and Bad Ones.

The only reason I Post a Forum like this, is if you don't, when Misinformation gets started, it is hard to set straight again. To me, it is the same as the Hoax of Global Warming!!

The last thing, If you can't find somebody to do a good Babbitt Job, and go to inserts, and it works out for you, more Power to you. But don't blame babbitt, for bad workmanship. Thanks Herm.

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PackardV8, at least one of the publicized methods for converting the 34 and prior detachable block Packard 8s to inserts required the notching of the rod bolts to get enough clearance for the insert. Not something I'd feel comfortable with - I stuck with babbitt and have had no issues, getting a very good service life from it.

I've always read that babbitt is easier on the crankshaft journals and I believe that when Packard when to inserts on the senior cars in 1935, they also went to a hardened crank journal.

Edited by Owen_Dyneto (see edit history)
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PackardV8, at least one of the publicized methods for converting the 34 and prior detachable block Packard 8s to inserts required the notching of the rod bolts to get enough clearance for the insert. Not something I'd feel comfortable with - I stuck with babbitt and have had no issues, getting a very good service life from it.

I've always read that babbitt is easier on the crankshaft journals and I believe that when Packard when to inserts on the senior cars in 1935, they also went to a hardened crank journal.

I'am with you on that Owen, on not wanting to notch rod bolts for clearance, myself as a bearing builder when you bore a rod Forging out for any reason, it cant do anything but weaken a rod all though some rods lend them selves more than others, and when notching any bolts, then you could have Torquing, and or bolt stretching problems. I think from my stand point as a Rebuilder, if that is what the owner wanted, I think I would get in writing, relief from any responsibly from any possibly of damage that an exploding rod could cause an expensive Newly rebuild Packard block.

And again, I am not against inserts, but when babbitt is getting a bad rap, of failure, and reasoning is because it is babbitt, and not workmanship, that would be just plain wrong!! thanks Herm.

Our Bearings of 1969

Shot 62

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Edited by herm111 (see edit history)
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A new question, but related to this topic.

Having a problem with one of my rod bearings on a 6 cylinder Olds. Contact area across the surface is OK after lapping in with Time Saver, but am confounded with the balance between the shim adjustment and the rod torque.

When taking up the rod bolts at a .002" clearance the crank will not turn. If, however, I add shim stock to "make room" for the compressed rod bolts, I also am adding unwanted bearing clearance .

Suggestions ?

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A new question, but related to this topic.

Having a problem with one of my rod bearings on a 6 cylinder Olds. Contact area across the surface is OK after lapping in with Time Saver, but am confounded with the balance between the shim adjustment and the rod torque.

When taking up the rod bolts at a .002" clearance the crank will not turn. If, however, I add shim stock to "make room" for the compressed rod bolts, I also am adding unwanted bearing clearance .

Suggestions ?

It sounds like your rod is out of Aligment. How did you use your time saver, and your rod fitting method, or how did you do it. Thanks Herm.

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HERM

It has been suggested that my Time Saver mixture is too thin, and that I try again to lap the bearing using 4/1 ratio. The rods and pistons have not been removed..only the rod caps and bearing inserts in an attempt to correct an .030 gap.

Sorry to here of your accident Mr. Autolike, boy stuff can happen real fast, and not always for the good! The last time I fell about 14 years ago, I busted the end on one of my fingers, it took about 2 months of healing, so it wasn't so painfull to wave Good By!

The first thing, I should say is we would never use a product like you are using, not to say that you shouldn't. When you fit a rod, new, or used, on a crank, the rod should never be fit by it's self, as it should have its pistion on it. The first thing that should be done is the rod checked for Twist, Bend, and Off Set. If you don't, use the pistion for alignment, when the pistion is put in, it can change the rod contact to shaft setting.

I am not understanding where you would have a .030 thousandths gap at?

How, or what, are you using to measure your rod to shaft clearance?

Thanks Herm.

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HERM

Many thanks for your quick reply. The .030 was a typo..meant to say .003 Using Plastigage to check the clearance, which has been uniform across the shaft...

Mr. Autoluke, is your shaft and bearing clean, and dry, when you are using the Plastigage?

Thanks Herm.

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Herm

Following the directions from Plastigage, I have been coating the journal with #30 motor oil.. They claim that this is necessary to assure a uniform spread of the plastic when under compression from the cap bearing.

All surfaces have been carefully cleaned before applying the Plastigage.

Hope to return to the project by Saturday, and will report my progress.

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Herm

Following the directions from Plastigage, I have been coating the journal with #30 motor oil.. They claim that this is necessary to assure a uniform spread of the plastic when under compression from the cap bearing.

All surfaces have been carefully cleaned before applying the Plastigage.

Hope to return to the project by Saturday, and will report my progress.

ok, Real fine, sounds like you are doing everything just right, Plastigage never used to say any thing about using oil with the plastigage, and there are still a lot of guys, that will argue against it. But if oil is not used, you will get a false reading, and always read the shaft, not the bearing. May be tonight, I will post a new post on Plastigage, with pictures.

keep up the good work. Herm.

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HERM

Many thanks for your quick reply. The .030 was a typo..meant to say .003 Using Plastigage to check the clearance, which has been uniform across the shaft...

Question Mr. Autoluke, you have .003 thousandths clearance, what is the size of the shaft, and what size are you shooting for, and how thick is the shim packs in the rods.

Tinindian, has it right, which is .001 thousandths per inch of shaft, that is minimum, or, 1/2 thousandths more Max.

Unless I missed something, you should only have to pull shims.

Let me know, Herm.

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  • 1 month later...
Guest kritiana08
Could you please post the year & make of the car in the 1920's that has inserts instead of babbit on the connecting rod journals.

Splash-oiled motors like the Model A had a factory bearing "oil clearance" of 0.0015" on the rods.

Pressure lubricated insert bearing motors (steel shell / thin babbit lining) usually run about .001-.003"

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Splash-oiled motors like the Model A had a factory bearing "oil clearance" of 0.0015" on the rods.

Pressure lubricated insert bearing motors (steel shell / thin babbit lining) usually run about .001-.003"

Mr. Kritiana08, Yes, the clearance on the Model A Ford Rod is one thousandthts per Inch of shaft, as well as most auto bearings, even pressure!

In a Federal- Mogul, Engine Bearing book, any given engine, lets use a 454 Chevy Rod size. The 454 has a rod shaft size of 2.1990, to 2.2000, which is a .001 to play with, + or -- . The Federal- Mogul Book says a Minimum of .0005, and a Maximum of .0028. So you have .0023 difference between, the low, and the high.

You have to remember, the shaft has a 1 thousandths + or --, or more depending how good the guy is that ground it, and or wear.

Another fact is when the shaft hits operating Temp., the rod shaft being of 2.200, will expand, at its least .00015, if not .002. more then when it is cold.

So, If we use the + or -- Figures of the books Minimum of .0005, or even your .001 thousandths, and the crank expands 1- 1/2 to .002, where is the OIL clearance going to come from, It is not the crank that will wear, it will be the bearing, and you just don't want that.

The reason the bearing clearance is spread like .0005, to 2.2000 is being there can be so many combinations of clearance you can end up with, as there is no shims to adjust with, as the tighter the clearance towards the bottom, the more careful you have to be, so the correct clearance is also .001 thousandths per inch of shaft, or like we have used for 44 years, Plus .0005. Max.

So if you go smaller then that, the Penalty to pay is removing some on the first layers of bearing surface!

Thanks Herm.

Here is an example of not enough oil clearance, most of the time you won't know right away, on a high oil pressure engine , just depends how severe!

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