MTFCA Forum

09 to 23 front bearing was shaped different because the front cam lobes were not lengthened as were those on later camshafts. There are examples in quite a few sources eg Fahstocks articles, parts catalogues etc. I belive the Model T manual has illustrations.
There may be other changes I'm not aware of but that's the major difference.

Early bearings had no babbitt, don't know when the change, I'll check my stock of bearings later to see if I still have them.

Check this article by Glen Chaffin on Cams. Talks about end play and differences in early and late cams.

The "early" front cam shaft bearings have a notch on the rearward facing end. This notch was to provide clearance on the top side of the bearing for the #1 exhaust lifter. The earlier cams had a narrower front lobe than later camshafts. The notch was troublesome because the rear face, being interrupted, could not effectively control the forward thrust of the cam. Over time, the front cam lobe would begin to wear into the notch. I suspect this was not a great issue with the straight cut timing gears, but the introduction of the helical cam gears increased the forward thrust of the cam. Ford solved this by making the front cam lobe wider, which allowed for a shorter front bearing, eliminating the clearance issue with the valve lifter.

Kerry is correct, early cam bearings were not babbitt lined. The cam journals ran directly on the cast iron bearing.

Early, early cam bearings have no babbit. They also look radically different in that instead of the solid body as the later ones have, they have ribs, like cooling ribs that contact the block on those rib edges. Much less contact & wear those ribs into the block to fit looser faster.
I don't know when they changed to the solid type body. There must be guys out there that have found these early bearings in original motors that can narrow the time they were used.

Back to Martynn's original post. Can anyone provide a decent image of what the early front cam bearings look like? It sounds like he is working on another of his excellent mechanical drawings of the Model T components, and he would like this drawing to be as accurate as possible.

Keep crankin',
Eric

I will try to dig out an example of the style that John refers to above.

I will try to dig out an example of the style that John refers to above. On Edit- here are a few pictures of the true early cam bearing. This bearing has had the rear side ground off at some point (on the left in the pictures) so it appears shorter with the notch removed. This is the only example I had. The clip was still used in the center groove to hold the shells together.

I found 2 early cam bearings. The one on the left is like Dans. (not as clean)
The one on the right, I suspect is earlier.
You can see the part # in raised cast. T41 or T411.
Note there is 2 ring groves. One on each end. Only one ring installed.

Maybe some of the guys that work/have worked on early motors can tell us the correct years they were used.

Felt like the pic needed some help

Very nice.
It's all I can do to get my wife to take the pix, send to me, down load, resize, place, describe & not lose the whole mess & start over.
Therefore, your ability impresses me. Thank you.

Martynn- the one I posted the picture of was a front bearing. The non-modified end has a large radius on the bore on one end as do the later front bearings. This radius was necessary to allow clearance for the radius on the front cam journal adjacent to the flange. Too bad the one I have has been modified on the rear side......