Camshaft front bearing loose in block, any fixes ??

[dobro1956]

The front camshaft bearing shell is loose in the block. I have had this happen before, and have shimmed the bearing shell in the block and also used press fit sleeve retainer. But neither is a good fix. Are there any more fixes out there. My Babbitt is perfect in the shell, but I have about .009 play up and down between outside of shell to the block. . There is little to no play side to side. Another thing that happens is the hole in the shell that fits the anchor bolt nipple will often wear. That usually cause the bearing shell to rotate a small amount and also allows the bearing shell to move front to rear changing the end play runout and causing more wear to the block Any ideas will be appreciated.

[Gene_French]

Donnie:
is the wear in the block or on the bearing shell ? to replace the bearing shells would be the simple , cheap repair if the bearing is worn … the block … more difficult to machine oversize and make a new bearing with oversize diameter … would need to do some careful measurements of both features ...always an optimist...Gene French

[Norman Kling]

I don't know how many miles it will last, but I did this about 10 years ago. I probably put on about 1,000 miles a year on this car and it runs very well.

This is what I did. I put some shim into the hole in the bearing where the tab on the end of the bolt goes in. The hole was worn. Then I installed the bolt. It has held the bearing in place ever since. It had a knock before and hasn't knocked since.
Norm

[dobro1956]

Im going to measure everything very well and see if the bearing shell has some of the wear. More than likely 1/2 the wear is on the shell and 1/2 in the block. I do know the anchor hole is worn and tapered. I fixed it by peening the end of the anchor bolt and filing it to a good tight fit. But I can still move the bearing shell up and down .009 at the front of the bearing shell. I assume it is rocking on the anchor bolt. Ill keep fiddeling with it till I get it. I was just hoping someone had an easy "miracle fix" Thanks for the input....

[Dan Hatch]

Donnie: At one time there were Oversize on the OD bearings. I have not seen them lately. I think there is a need for these. You may check with the supplier and see. If you find who made them let me know. Thanks, Dan.

[dobro1956]

I did a little research and a lot of measuring today. Thanks to a conversation with Steve Lang about what they had to offer as to bearings. and him supplying me with the Ford factory tolerance specifications I have a good idea what is wrong with my bearings. according to the Ford drawings the front bearing shell OD is 1.372 to 1.373 and the block hole ID is 1.374 to 1.375. That gives a tolerance of .001 to .003 when new. Thank you again Steve .....

My bearing shell was 1.3725 perfectly in the center of the range. I believe it is a replacement bearing that has little to no wear.

My hole in the block measured side to side was 1.375. The maximum ID range but still within tolerance.

But the ID of the hole in the block measured up and down is 1.381 or .009 oversize. When I installed just the bearing shell into the block and shined a light from the inside, it appears all the wear is on the bottom side of the hole.

I know that some of the current repro bearings are egg shaped. An engine rebuilder that I know has made a die to insert the new bearing shells into and then put the die in a large hydraulic press and "press" the bearing shells back straight. Since I do not have a die or large press, and it is too far to go borrow his press, and since my bearings are good, I decided to shim my bearing shell.

I figured I had about .007 to .009 to shim. I had .005, .004, and .002 brass shim stock to work with. I cut a piece of the shim stock to a little less than the length of the bearing shell. I used a piece of .005 about 1-1/4 inch wide and a piece of .004 about 3/4 inch wide to start with. Working with just the bearing shell made it easy to trial and error the fit. I could not get the .005 and .004 to go in. So I tried two pieces of .004. and I could almost get them in but not easily. So I tried the wide .005 again with a narrow piece of the .002. It fit OK. I lubed the Babbitt cam bearings with engine assembly lube for final assembly, and just before I installed the cam with bearings for the final time I mixed up some JB Weld. I just used it to "glue" the two shims together, and then I covered the entire outside of the shims with a very thin layer of the JB weld. Just enough to make it sticky. Since I was installing the shim at the bottom, I wiped the bottom of the hole in the block with a little JB Weld. Again, just enough to make it sticky. I just used the JB Weld to lock the shim in place. I did not want to put a lot of JB Weld on the bearing shell or hole, so it would still be fairly easy to remove everything if I needed to at a later date. After installing the cam and bearings and before I installed the anchor bolts, and while the JB Weld was still "wet" I can not get any movement of the front shell at all. So I am happy with the results.

I have encountered this problem before. I have tried other "fixes" but this time I feel like I "fixed" it. I also believe this is more common than is believed.

Thanks for all the input.

Have fun and be safe ......

[Allan]

You have done well Donnie. The only thing I once did differently was to fit the bearing and shim, and the punch a hole in the brass shim so the stepped bolt could be fitted. This had the effect of shimming around the bolt too, making it a firm fit in the hole in the bearing shell, and preventing the shim from coming out.

Allan from from down under.

[Kerry]

Allan, if you are thinking of the yellow Duncan & Fraser, well, it did last about 10 years with the brass shim then spat it out in pieces. Those front bearings seem to take a flogging over time.

[BobShirleyAtlantaTx]

In the old days, a loose fit would be tighten by knurling a new bearing with a sharp center punch. Easy to do, lay the half’s on a vice or anvil and peck all over. You should obtain interference fit.

[michaelb2296]

Here's my , good nuff', suggetion. JB Weld . Wrap bearing with saran wrap, JB Weld block, shove cam in, put in anchor bolts (pull back out and wipe off then put back in) Make sure the timing gear and crankshaft gear are on to center it... In one hour, pull out cam and saran wrap (when its hardened but not cured). cut off excess. Let dry overnight. As long as you cleaned the metal thoroughly prior, it should last a very long time. They use JB Weld in the Navy on the ship engine bearings. done. That's the poor mans solution. Less than $5 fix.

[speedytinc]

Here's my , good nuff', suggetion. JB Weld . Wrap bearing with saran wrap, JB Weld block, shove cam in, put in anchor bolts (pull back out and wipe off then put back in) Make sure the timing gear and crankshaft gear are on to center it... In one hour, pull out cam and saran wrap (when its hardened but not cured). cut off excess. Let dry overnight. As long as you cleaned the metal thoroughly prior, it should last a very long time. They use JB Weld in the Navy on the ship engine bearings. done. That's the poor mans solution. Less than $5 fix.

Question. Doesnt the saran wrap make for extra, unwanted clearance? The bearing should be a light tap in fit.
If you peel the wrap, you have added 2X saran wrap thickness. If you left it on, it wouldnt last.
I wonder if a built up coat of JB machined down for the tight fit would take the pounding in use.
Would a paper thin coat of JB stick & stay in tact?

This re-awakend topic was BOT revived.

[michaelb2296]

.0005 to .001 is definitely within tolerance. JB Weld is impregnated with metal. Good to 550F and over 5000psi. As long as the surface is clean... I think it should last for a very very long time. poor mans solution.

[RGould1910]

Makes sense the wear is on the bottom of the block and shell due to valve spring pressure. I like the idea of using shims .

The jb weld trick plus saran wrap worries me because the epoxy will enter the voids in the outer parts of the shell, eg where the ring surrounds the shell. How do you then remove the bearing shell without making a mess of things?

If you weren't concerned about ever removing the bearing, simply jb weld it in place using the installed camshaft as a guide or pilot. Forget about the saran wrap.

Another approach that would work fine with jb weld or epoxy and saran wrap would be to machine a round plug the exact size of the bearing and insert it into the block with jb weld/epoxyslathered on inside of the block, after oiling the od of the plug and single wrapping it with saran wrap. I would also machine a hole in the center of the plug to accept the camshaft journal to maintain alignment.

I don't think saran wrap has enough thickness to create noticeable play. I've used it with jb weld in another application with success.

Overall saran wrap and jb weld or epoxy definitely have a place in a restorer's arsenal, but there are isues that must be addressed..