Babbitt vs Inserts

1

1929

Well-known member
what has the better advantage? is it true that with babbitts the head should be no more then a 5.5. If you are going to rebuild your motor, why not go with inserts even if it costs more.
 
IMHO there aren't many around that really know how to pour babbit. If the babbit gets too thick because the crank has been turned I don't think that is good either. Anyone else agree? When I had a motor built it was built with inserts on mains and rods. Inserts need machine work knowledge which I believe is more widespread than babbit knowledge.
 
mrtexas said:
IMHO there aren't many around that really know how to pour babbit. If the babbit gets too thick because the crank has been turned I don't think that is good either. Anyone else agree? When I had a motor built it was built with inserts on mains and rods. Inserts need machine work knowledge which I believe is more widespread than babbit knowledge.
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Inserts need machine work knowledge, I agree
 
I have one of each and and use them for touring. Quite frankly, it's difficult to really tell any difference. The Babbitt engine has an original CRAGAR head and a 5 speed and the insert engine has a Brumfield super head and a '39 three speed. You pay your money and takes your choice.
 
denis4x4 said:
I have one of each and and use them for touring. Quite frankly, it's difficult to really tell any difference. The Babbitt engine has an original CRAGAR head and a 5 speed and the insert engine has a Brumfield super head and a '39 three speed. You pay your money and takes your choice.
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who did the insert engine?
 
Babbitt as a bearing material will handle anything that inserts will. Don't worry about compression ratio. The difference comes at over 4000 rpm when pressure oil is needed and no one that I know of is making babbitted rods set up for pressure oil at that speed. I have heard that pressure to the original babbitted A and B rods was done back in the day, and maybe Jim Brierley has some historical knowledge on that. Jim has run pressurized babbitt mains on his Bonneville car for many years and that is a pretty good testament for babbitt.
My suggestion to 1929 is save the money (put it into your pocket, or a good camshaft and counterbalanced crank depending on your use) and go with babbitt unless you plan to go over 4000 rpm in which case you need pressure oil and only inserted rods are available for that so far as I know.
That said I think inserts are probably the wave of the future just because more people are learning how to machine for inserts than are learning to do babbitt. Maybe the market will change that if there is enough demand. Babbitt is cheaper because the machining is not necessary. Either way, ask questions and get recommendations. A bad job on either will have the same result.
 
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:rolleyes:
1929 said:
what has the better advantage? is it true that with babbitts the head should be no more then a 5.5. If you are going to rebuild your motor, why not go with inserts even if it costs more.
Click to expand...

Hey 1929,
Excellent question, to which there is a lot to consider when making choice. For example, I have a B block that was machined for inserted mains. Then new high end inserted rods were added. I did it this way, for what I considered...the loong run idea. That is, I envisioned running across the USA, to Alaska, etc..and wanted an engine that would give no trouble doing that. Now , you do not have to run full oil pressure to run inserts or badditted rods/mains, but for durability (look to modern engines longevity) , I decided to go to full pressure WITH full oil filtration ! Clean oil is the key, IMO, either way you go. I'm now building another B block with poured battitt both mains/rods, but again with full oil filtration system. I'm expecting the babbitted mains/rods to perform perfectly , if perfectly done ! That's a mouthful these days, that is , getting perfectly done Babbitt job, for reasons already stated-vs- buying modern inserts which are factory made and where the best machining/assembling IS the key. As you go along this information trail, you will see that the more perfection that you want (either way) will cost you more money. Someone said, put the money in your pocket, where the heck was he many years ago :rolleyes: ! When the 'bug' to go farther, smoother, faster hits you...this quest can be a bottomless $ pit, eh :) !
I say done correctly BOTH can and have been used successfully, even at higher RPM. Do either wrong, and you will end up wishing that you had done the other 'correctly'...maybe.

BTW you can use full pressure with babbitted rods. You just have to block of stock oil holes in rods, and get crank shaft that is drilled for full pressure AND do a number of other 'things' to accomplish the job.
I recommend that you obtain/study a book by a member here (Jim B), as it will help explain a lot of how to and why/why not questions/answers.

I do not think that on a 'good engine', that high compression ratio of head has detrimental effect. Just more power to be gained if tuned right and run with complimentary equipment, i.e.- cam/carb/exhaust, etc. I've run 8:1 on a sturdy B with positive results.
 
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A models work fine with both Babbitt and inserts and both will handle almost any compression or power an A model can generate
I choose inserts because where I live good Babbitt guys are few and far and have long wait lists
I drive my A 10,000-20,000 miles per year on average so in 7-10 years my engine will need a rebuild and my chances of finding a Babbitt guy then will not be any better
but I will be able to change my inserts myself quickly and easy
 
I was told by parts and restoration shops that send their engines to an engine rebuilder that has over 30 years experience and a great reputation doing both inserts and babbitts with a I think a 2 year warranty that will not put over a 5.5-1 head on a Babbitt engine. Its not about spending too much which is easy to do with this car as Ive begun to notice, its what is the best choice. I would like to get the oil filtration system cause I did see when I removed the oil pan and valve cover not such a clean motor, but then again previous owner was not using detergent oil which I heard some will not do. thanks for the advice.
 
If babbitt is superior to insert bearings, than we would still have babbitt bearings today. Insert bearings are the way to go.

The last babbitt bearing car engine I am aware of was the 170 cu. in. Ford six cylinder used in the 1960s Falcons. Did you know that GM and Chevy 6 cylinder engines through 1953 used splash (spray bars) oil lubrication of its connecting rods.
 
With Babbitt the bearings are made to fit the crankshaft --it is somewhat adjustable to a crankshaft not quite an exact undersize

With inserts the crankshaft is made to fit the inserts, has to be the exact size for the inserts to have proper clearance

When there is a babbitt failure most likely the crankshaft and bearing bore are not damaged---just the babbitt

with inserts when there is a failure most likely the crankshaft will be damaged, and if the insert spins, the rod, or block

Babbitt has a greater capacity to absorb "dirt" than inserts ---the babbitt layer on an insert is thin
 
hardtimes said:
:rolleyes:

Hey 1929,
Excellent question, to which there is a lot to consider when making choice. For example, I have a B block that was machined for inserted mains. Then new high end inserted rods were added. I did it this way, for what I considered...the loong run idea. That is, I envisioned running across the USA, to Alaska, etc..and wanted an engine that would give no trouble doing that. Now , you do not have to run full oil pressure to run inserts or badditted rods/mains, but for durability (look to modern engines longevity) , I decided to go to full pressure WITH full oil filtration ! Clean oil is the key, IMO, either way you go. I'm now building another B block with poured battitt both mains/rods, but again with full oil filtration system. I'm expecting the babbitted mains/rods to perform perfectly , if perfectly done ! That's a mouthful these days, that is , getting perfectly done Babbitt job, for reasons already stated-vs- buying modern inserts which are factory made and where the best machining/assembling IS the key. As you go along this information trail, you will see that the more perfection that you want (either way) will cost you more money. Someone said, put the money in your pocket, where the heck was he many years ago :rolleyes: ! When the 'bug' to go farther, smoother, faster hits you...this quest can be a bottomless $ pit, eh :) !
I say done correctly BOTH can and have been used successfully, even at higher RPM. Do either wrong, and you will end up wishing that you had done the other 'correctly'...maybe.

BTW you can use full pressure with babbitted rods. You just have to block of stock oil holes in rods, and get crank shaft that is drilled for full pressure AND do a number of other 'things' to accomplish the job.
I recommend that you obtain/study a book by a member here (Jim B), as it will help explain a lot of how to and why/why not questions/answers.

I do not think that on a 'good engine', that high compression ratio of head has detrimental effect. Just more power to be gained if tuned right and run with complimentary equipment, i.e.- cam/carb/exhaust, etc. I've run 8:1 on a sturdy B with positive results.
Click to expand...

What book would that be / Thanks
 
"If babbitt is superior to insert bearings, than we would still have babbitt bearings today."

Inserts are quicker, cheaper and easier to mass produce and replace. Babbitt bearings are still common in industrial applications.
 
PC/SR said:
Inserts are quicker, cheaper and easier to mass produce and replace. Babbitt bearings are still common in industrial applications.
Click to expand...

Bingo! Our cars were produced in an age where technology was expensive and labor was cheap; that dynamic hasn't existed in the auto industry in 50-60 years...today, quite the opposite is true.

Personally, I'm amazed that the myth of 'babbit sensitivity' is so pervasive. Diesels used babbitt for decades under much higher cylinder pressures than we would ever see with a 5, 6, or 7:1 head.

For my build, I chose a counterweighted crank, lightened flywheel (36#), and stock oiling on babbitt bearings. I believe babbit is far more forgiving of unfiltered oil and feel confident that even a 'moderate' performance engine is really not capable of spinng RPMs that would exceed the ability of the rod dippers to do their job(s)...valve float is our friend here.
 
PC/SR said:
"If babbitt is superior to insert bearings, than we would still have babbitt bearings today."

Inserts are quicker, cheaper and easier to mass produce and replace. Babbitt bearings are still common in industrial applications.
Click to expand...

The one thing that is bad with inserts, are, the inserts you used today, may not be made tomorrow, and or in the size you need. It happens all the time.

Herm.
 
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