MTFCA Forum

Is anyone using the new Cam bearings being supplied by the vendors having issues with fit? I am trying to repair a .030 cam thrust issue .my cam is a new 280 but was installed with used bearings years ago.i purchased a new front cam bearing correct for the cam but am finding it to be out of round enough to not fit into the block.it also is very snug length ways .is it common to have to machine them to fit? Or is there a better option parts wise.thanks in advance

I believe a rebuilder I know made a fixture to squeeze them round in a press.

Bearings have to be fitted to the cam. They are not plug and play.
Look into the cam thrust kit for your old bearing. Dan

Dan Hatch wrote: ↑

Wed Dec 11, 2024 9:07 pm

Bearings have to be fitted to the cam. They are not plug and play.
Look into the cam thrust kit for your old bearing. Dan

Lang's shows .003 OS and standard. If they are standard, would they still need to be fitted? Maybe the OP got the oversized ones?

Eight years ago, I bought new cam bearings. The endplay clearance was ok. But, I had to scrape the babbit to get a proper journal fit. It was somewhat time consuming.

Art Mirtes

The issue isn't bearing to cam fit it's bearing to block. I have seen the die and press pictures to make round again but have no access to anything like that.

Kenneth:
i re-machine the cam bearings by chucking on a mandrel and precision grinding the O.D. on a punch grinding fixture ... most machine shops should be able to do this operation ... this should have been done in the original manufacturing process ... Gene French

The last cam bearings I bought fit the block just fine. However, they had more clearance with the camshaft than my original bearings. So, back in the engine with the old bearings...

(It was a new Stipe cam BTW)

KenHaverhill wrote: ↑

Sat Dec 14, 2024 9:59 am

The issue isn't bearing to cam fit it's bearing to block. I have seen the die and press pictures to make round again but have no access to anything like that.

A lite squeeze in a press will do it. A vice might work if no press.
Measure the od to confirm where & how much squeeze is needed.

Can one make an oilite bushing reliner for the old outer cam bearing or would it wear the journal faster?

RecklessKelly wrote: ↑

Mon Dec 16, 2024 8:42 am

Can one make an oilite bushing reliner for the old outer cam bearing or would it wear the journal faster?

If I were going to try any bronze, it would be just regular bearing bronze, (660). I have never been a big fan of oilite. Besides, since it holds its own oil, oilite is made for areas that don't otherwise get adequate lubrication. Cam bearings should be getting their fair share.

BTW, Models NRS use bronze cam bearings...

Jerry VanOoteghem wrote: ↑

Mon Dec 16, 2024 10:04 am

RecklessKelly wrote: ↑

Mon Dec 16, 2024 8:42 am

Can one make an oilite bushing reliner for the old outer cam bearing or would it wear the journal faster?

If I were going to try any bronze, it would be just regular bearing bronze, (660). I have never been a big fan of oilite. Besides, since it holds its own oil, oilite is made for areas that don't otherwise get adequate lubrication. Cam bearings should be getting their fair share.

BTW, Models NRS use bronze cam bearings...

And the Model A didn't have any and ran just ran in the block, but they were larger.

I was thinking oilite being softer than solid metal, wouldnt wear the journal so much.

RecklessKelly wrote: ↑

Mon Dec 16, 2024 11:46 am

I was thinking oilite being softer than solid metal, wouldnt wear the journal so much.

I don't find it to be softer. It's a compressed powdered metal, (i.e. sintered). Its granular structure allows for a porosity that holds oil. I feel that since it's made of compressed/compacted grains of bronze, it becomes harder in the production process than regular bronze. (Of course, there's many different grades of bronze as well.) I know some folks use it and like it, so maybe I'm wrong, but my experience with it has not been great.

Gotcha on that.

Anyone know the proper OD diameter of a cam bearing? Is the pictured jig exactly the size of the diameter or a few thousands smaller?
Thanks.

Mike Bender is the man who made the jig, he has a number of videos on YouTube one of which shows him using it during the cam installation. This web page gives some good information and dimensions.
https://mtfctulsa.com/Tech/cam_bearings.htm

Someone was asking about cam bearing dimensions. This drawing is from The Henry Ford’s website.

Here is one made from bronze

Early versions were solid cast iron. (no Babbitt) I have made some from scratch from cast iron stock without a layer of Babbitt.
Model A's cam runs in the iron block with no bearings.