Apis Mellifera
Apis Mellifera Dork
6/27/22 8:08 p.m.

I like old junk, but never had anything old enough to have babbitt bearings until recently.  The main and rod bearings in Model T Fords are cast-in-place babbitt, though modern shell bearings can be retrofitted with machine work. 
 

Anyway, while finally getting to drive my 1922 T Saturday, it developed  a sudden knock.  Here's the inspection plate removed from the bottom of the engine.  Apparently babbitt can crystallize and suddenly crumble.  In my case, that meant the rod bearing on #1 spontaneously self-ejected.  Surprisingly the journal is still mint.  With no oil pump to worry about, I think I can just hose out the crumbs from inside the engine, swap in a new rod, and carry on.
 

Stampie
Stampie GRM+ Memberand MegaDork
6/27/22 8:16 p.m.

I'm in for the learning.

ShawnG
ShawnG MegaDork
6/27/22 8:24 p.m.

You should be able to.

I've dealt with a few N,R,S, and T engines. 

Are your rod caps hinged or the two-bolt style?

If you're ordering bits, check to see if your transmission inspection cover has a filter screen added to it. If it doesn't, add one, they're only a couple bucks and will help keep the bigger debris out of the oil stream.

Before anyone asks. T engines and transmissions share an oil system.

Lang's generally has better parts than Mac's and they're easier to deal with since Eckler's bought Mac's.

californiamilleghia
californiamilleghia UltraDork
6/27/22 8:27 p.m.

Are there  grades of Babbitt ?  
 

 

 

Apis Mellifera
Apis Mellifera Dork
6/27/22 9:10 p.m.

Two-bolt, light rods.  Looks to have original cast iron pistons.  I fitted the hogshead screen a while back, but have not looked inside since the bearing failure.  No idea on alloys/grades/lifespan of babbitt.  This could be the original 100 year old stuff.

My plan is to pull the head off and fit new high compression aluminum pistons on re-babbitted rods.  Rod and main journals should spec at 1.248-1.250".  The post-failure journal measures 1.246" and passes the fingernail test.  No scoring or heat damage.  Just normal wear so I think I got lucky.

ShawnG
ShawnG MegaDork
6/27/22 11:31 p.m.

They run a lot smoother with alloy pistons, you'll like it.

Jerry From LA
Jerry From LA SuperDork
6/28/22 12:01 p.m.

You should pose this question on the Classic Motorsports side as well.  Someone might be able to explain the crystalization as well as have the parts sitting on the shelf. Plus the pros and cons of re-babbiting vs shell bearings.

preach (dudeist priest)
preach (dudeist priest) GRM+ Memberand Dork
6/28/22 4:35 p.m.

I work with an old Ford fan. I will ask him.

preach (dudeist priest)
preach (dudeist priest) GRM+ Memberand Dork
6/28/22 5:01 p.m.

So far he said: 

"The best thing to do is have the main line machined for clip in bearings, babbitt is a dead art, hard to get good lead."

At work we use a place in MA to re-babbitt. I can get you the name of the place if you want.

Apis Mellifera
Apis Mellifera Dork
6/28/22 5:28 p.m.

See my thread in the Builds section for further updates.

preach (dudeist priest)
preach (dudeist priest) GRM+ Memberand Dork
6/28/22 5:40 p.m.

I failed to find it but what's up with the 906?!?!?!?!

Apis Mellifera
Apis Mellifera Dork
6/28/22 8:47 p.m.

In reply to preach (dudeist priest) :

It's here:

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/1922-model-t-engine-build-and-more/196122/page1/

The 906 is a long term project I started several years ago and have been accumulating parts slowly. At this point I have most everything I need to build it.  Original parts do not turn up very often though.  That said, authenticity in race cars, especially old ones, is like Lincoln's axe - the head has been replaced once and the handle twice, but it's his original axe.  Mine will probably be less original than most original 906s out there today, but definitely more original than some.

WonkoTheSane
WonkoTheSane GRM+ Memberand UltraDork
6/29/22 11:03 a.m.

I've worked with a shop that does babbitt bearings for Rolls Royce and other plane bits.   I don't think they deal directly with the end users, but just throwing this out there if there's any shops looking for work in that arena.  Great company and people to work with:

https://www.jensenmachine.com/index.html

 

Our Preferred Partners
QBs9ximOBsSjKetsZ1GWkwahLWLK39F8dVlqklyBb0cBjNlMipeksiqE5xiZlLuY