Replacable babbitt bearing inserts?

[dumb person]

In the era of the model T there were cars with replaceable babbitt bearing inserts, much like the replaceable bearing shells used today.
What would prevent a model T block being lightly machined (just enough boring to clean up the bearing area?) and make replaceable bearing inserts of babbitt a success?

[CharlieB]

I'm looking around because I know this was discussed before. I think it was the MTFCA site though. Don't think anything positive was said about it. I was left with the impression that inserts wouldn't hold up in an un-pressureized system. Also I believe that if it was feasable we'd have heard more about it. Personally it's the one thing that I really don't like about the T. That is I can't replace bearings myself in my garage if the need arises. It must be sent out and there's some pretty dicey "rebuilders" out there.

[Royce P]

The drawbacks of installing insert bearings in a Model T:
1. You have to use an available bearing that will fit between the main bolts. There's not much room. Therefore the only way to get enough room for something that is available means you have to cut the crank way down in diameter. Which results in another expensive drawback.
2. You can't machine the stock crank that small and expect it to last. So you end up having to buy an expensive billet crank.
3. The rods have the same problem. The solution is to buy expensive custom aftermarket rods and pistons.

In the end you are spending a ton of money to achieve.......what? Most of us can drive a Model T for decades and never wear out the main or rod bearings.

If you want to make 150 horsepower buy a 1975 Cosworth Vega engine and then figure out why the planetary transmission and rear axles keep blowing up. The result would be the same - you would not have a Model T engine any more. But the Vega would be a lot cheaper and quicker way to get rear axles and transmission parts to fail.

Originally Posted by dumb person

In the era of the model T there were cars with replaceable babbitt bearing inserts, much like the replaceable bearing shells used today.
What would prevent a model T block being lightly machined (just enough boring to clean up the bearing area?) and make replaceable bearing inserts of babbitt a success?

[redmodelt]

Early 4 cylinders Chevrolets used insert bearings on the crankshaft. Generally I think the babbitt was thicker then what we see todays on insert bearings.

[dumb person]

Originally Posted by redmodelt

Early 4 cylinders Chevrolets used insert bearings on the crankshaft. Generally I think the babbitt was thicker then what we see todays on insert bearings.

Yes, that was what i was thinking. Only problem is those inserts tend to be thicker than adhered babbitt in a typical T block.

[Kohnke Rebabbitting]

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The babbitt in a solid Chevy 4 insert is about .075 wall, give or take a crank grinding.

Model A's, and T's are about .040 to .050 wall, with variances for crank grinding.

The center Chevy 4 brass inserts, has a thickness of about .030 wall, depending on crank size.

Babbitt in a T,A, and B block does not adhere to a cast iron block.

Herm.

[Coreywalker]

"Babbit in T,A, and B blocks does not adhere to a cast iron block" I'm confused. The babbit is poured into a T block and it adheres to it. Maybe I'm missing something? I have a 25 Overland engine and it has babbit inserts. They are thick and don't have a steel backing like modern inserts.

[Kohnke Rebabbitting]

There are 3 ways that babbitt is held in a block.

1. You have a block that will have Bronze, or steel backed inserts. These will be tinned, and a wall of babbitt sticks to the tinning.

2. The insert will be made of solid babbitt and is set in the block, with some form of anchor system.

3. This is what Ford used, babbitt is poured in the block, and having anchor holes, which most people think holds the babbitt in, which it dosn't, you then peen the babbitt to set the babbitt tight to the block wall. If you don't, it will not last, as seen buy all the failed babbitt pictures on the Ford Barn over the years.

One last thing, a K.R. Wilson babbitt hammer is a very poor tool to peen the babbitt with.

Herm

[Erik Barrett]

The four cylinder Chevies were not "insert" engines as we think of them today. They used bearing shells that were babbited and then set in the block and line bored. You did not just take the old ones out and install new ones. I don't think the first real insert replaceable bearings came out until the 30's.
The small size of the T crank would make it hard to find a suitable bearing, and then you would have to use at least a couple in each one to make them wide enough. Even then it's still a problem using inserts in a T because they have zero tolerance for trash in the oil. They like pressurized, filtered oil. Not found in most model T's. Babbit bearings will outlast them if installed and maintained properly.