If I remember correctly, somebody said to turn down the outer diameter of the rear cam bushing. Lube the bearing surface, coat it with JB Weld. Then install the cam in a normal manner. This will allow the rear bushing to align itself correctly without any machining..... Did I remember correctly? Or was I influenced by my Soco?

Why do this??

This will allow the rear bushing to align itself correctly without any machining....

The reason that I asked, other that curiosity, is that my old bushing was worn at the top surface. The oil groove was completly worn away. That leads me to believe that something is out of alignment.

Thunder
Was the bushing actually worn (was the cam shaft loose in the bushing).

If your cam shaft bore is not aligned properly your going to have more problems than a missaligned cam. As Les stated is the bushing really loose on the cam journal? Is the cam straight? Have the cam bearings been rebabbited incorrectly? Was the correct bushing installed?Etc... Try to check all other those things out before rigging a bushing in a block with JB weld and other things.

I've heard this idea before. I believe the thinking is that the cam bearing bores were not aligned properly during the manufacture of the blocks. Or, that the bores, for whatever reason, are no longer in line.

If that is the theory, I would strongly disagree with that notion. Ford quality control simply would not allow this situation to occur. Nor would I expect that the engine block would distort in such a way as to move the cam bores. Even if wear were to develop in the three cam bores, it would only serve to loosen things up, but not cause misalignment.

With all possible respect for the individual who suggested the JB weld technique, I personally would not go that route. If such misalignment were to exist, I would make an eccentric bushing to compensate for it.

I have built engines where the rear cam bearing bore was .010" out of alignment with the front two bores. None of the bores were worn, so it was pretty apparent that the block came from the factory that way. As Jerry said above, I would not be a fan of the JB weld solution. Boring a rear bushing to correct the problem is the best solution in my opinion. I do have an align reamer that is a period tool used to align ream the bushing, so the problem must have existed back when. Dan

Dan,

I guess I gave Ford Q.C. too much credit! How often do you see this level of misalignment?

Jerry- only when the customer is due to pick up the engine the next day. I may have seen 3 of these in 30 years of doing it.

Les. When I purchased the new cam, I also got the new bearings & bushing. Just for laughs, I checked the rear bushing for wear. It was loose, up & down, and tight side to side. So in an earlier post, I asked if it would be beneficial to drill an oil passage for the rear bushing. When I looked at the new bushing, I saw that an oil groove was cut into the bushing. The old bushing, was so worn, that the groove was barely visible. I was thinking that if the bushing was worn, it would wear at the bottom, due to the pressure of the valve springs. With it worn at the top, that leads me to believe that the rear bushing is a bit low. Just thinking here. Dans response strengthens my suspicions....

With that said, I thought that somebody had suggested the JB Weld fix. It sounds intriguiging, but I'm a bit reluctant to try it. So it seems that if it is misaligned, I should try an eccentric bushing?

It was probably me that suggested the regular formula JB Weld fix. I have done the technicque on my 12 and my 10. The alignment on the 12 was way out so there was no way (without the Wilson tool or equivalent) I could install the bushing and keep things aligned. I was so impressed with the result I used it on my 10. I have a few thousand miles on both cars and have experienced no problems. I tore down both the 12 and 10 engines for unrelated reasons and the fix is holding up fine.
I admit at first I was concerned the temperature of the oil bath might cause problems but I researched the heat tolerance of JB Weld and concluded it was fine. I have also used JB Weld and epoxy in the pan to fill rust holes without any problem. So I am convinced fix won't be compromised by heat.
One observation to add. JB Weld is thick and requires the bushing turned down say 20 to 30 thous to have enough room. You don't want any voids. Depending on how far out of alignment the hole is, you could use a thinner epoxy and get the clearance quite a bit closer.
All that's probably unnecessary. I personally am satisfied with the fix the way it is.
One thing to add, its really impressive to see how smooth the cam turns when everything is perfectly aligned and you get an honest 1.5 thou clearance on all three bearings.
Thunder, there are period reamer fixtures that accomplish the same thing. One is guided by the holes in the block for the first two bearings, the second by the actual bore in the bearings. I believe the first is a Wilson tool, the second a Stevens. If you're interesed, I can get the Wilson tool out and post a photo.

Thunder,

If you decide to go the eccentric bushing route, you'll first need a way to measure and determine just how far off location the bore is. Second, you'll need a bushing with an undersized bore, usually available from a place that sells ball bearings and such. By me, it's Motion Industries.

If you don't have a Stevens or Wilson tool, as mentioned above, you will need access to a lathe equipped with a four jaw chuck or a milling machine. With either machine you can bore an offset hole. The word is "bore", not ream. reaming will tend to follow the existing hole.

AHA!!!! Im not totaly crazy! It WAS suggested. Thanks Richard, the fix sounds feasable. As for the engine temp, I've used JB Weld in other non-structural areas on other projects. With ABSOLUTLEY no problems due to heat or oil saturation. It worked wonders on a GM throttle body project.

Like I said earlier, because my rear cam bushing was worn on the top surface, I thought that there might be an alignment issue.... In the long run, your suggestion sounds a lot more affordable than an eccentric bushing. And something that I could do here in MY shop.

I really need to double check the alignment though, before going any farther.

Thanks again.

Well I went ahead and dry fitted the cam. I slipped the rear bushing on for laughs. Sure enough, I can see right into the block on one side. So its deffinatly (sp?) off center.

So far.... Undersize lifters, and a misaligned rear cam bushing. This is getting to be fun....

Here's my take on alignment. The two front bearings we use are either used ones or repops. Often they do not center the cam. Sometimes they is so far off, they won't fit in the block with the cam installed. It doesn't take much misalignment of the bores to throw the cam off center so it binds in the rear bushing. My guess is that this accounts for most misalignment issues.
What I do is this. Find the two front bearings that fit the best, then float the third with JB Weld.

"Sometimes they is so far off, they won't fit in the block with the cam installed."

In this case, my suggestion would be to fix the original problem, not create a new one. This is just my opinion. - if the cam was bent would you do the same thing? Of course not!
Dan

I'm inclined to believe that the cam is straight being that its new, and as I turn it in the block, it remains off center. So I have three options, as I see it. 1) The JB Weld fix. 2) An eccentric bushing. Or 3) align bore the rear bushing hole, then install an oversize bushing. Are there any other options that I've missed?

One of the first two bearings might be off center?
Norm

The #1 and #2 bearings are tight in the block.

How about the bearing bores on 1 & 2? I'd be inclined to believe the bore in the block. Rather than tinker with the rear bearing, fix #1 and #2 bearing bores. The cam bore is what indexes the mains bore and hence the cam to crank clearance. You could end up with the cam gear too loose or too tight on the crank gear. Neither add to gear longevity. Not to mention generator gear alignment. (If equipped.)

OK.... But then I would need a bushing of some sort for the #1 and #2 cam journal. Right?

Thunder,
It seems tome the center bearing has been bored off center. Maybe if you rotate it it will become apparent it is not centered. I'd sure like to know if it's the #2 bearing.

Regards
Noel

Thunder, My assumption about #2 is predicated on the #1 bearing making good gear timing clearances.
Noel

UHHH! Timing gear clearances.

I don't understand why you would need a bushing for 1 & 2. Mount the bearings in a lathe and see if the bores are concentric and centered to the OD. If not, send them back to the vendor or rebabbitt and bore yourself. You mentioned the bearings are tight in the block. Is that with the bearings on the cam? There may be enough meat (babbitt) to correct a small amount of misalignment by re-boring the bearings to the correct clearance.

How long did this engine run with its original cam bearings?

Why not just replace the cam bearings and the bushing? I bet if you do this you can slide the camshaft assembly in easily with a couple of light taps.

Ted. I dont know how long it ran with the original bearings. I've replaced it with a reground cam with new bearings. But as I said at first, the rear bushing was worn, off center.

Ken. I guess thats the answer that I'm looking for. If I spin the cam, with the bearings in place, then I should be able to tell if the bearings are off center. Correct?

Dan, the method I use is based on the same principle as the Stevens tool. Unlike the Wilson tool, it uses the bore of the first and second bearings as a guide to ream the third bushing. My method uses the cam itself guided by the bores of the two bearings.
It was good enough for those using that tool, its good enough for me.

Thunder - Spinning the cam in the bearings won't tell you anything. You need to spin the bearings to see (measure) if the bore is correct. The OD is fixed. The ID is what you need to verify--Is it centered to the OD?

Ken. What I was asking is, I should spin the cam, WITH the bearings on, then measure the concentricity of the outside of the cam bearings. Correct? That should confirm that the bearings are centered or not. Right?

Okay gotcha. That should work if the bearing halves come together. Some can be pretty rough on the outside. You'll probably have to use a piece of shim stock (or similar) under the indicator. Measure at both ends of each bearing. They may wobble.

Got it. Thanks a bunch.

The primary load on the cam is from lifting the valves against the valve spring. This is in the vertical plane so it makes sense that most of the wear would be up and down.

The engine ran 80 or so years with the cam bores as they are now. It should run a few more.

Install the cam bushing and reassemble the cam.

In the two blocks I have done there was no need to ream the bushing after installation.

Sure seems complicated. I install all the bearings in the block and run a dummy cam covered in timesaver into them. Dead straight and honed to the proper clearance.

I like it, Tim! Have you ever had a situation where the dummy cam doesn't fit easily into the third bushing?

I hesitated putting up that photo, I thought I'd get a rash of crap over it because it adds a fair amount of time ($) to each build and it's "not the way Henry did it", "snake oil", and probably something along this line - "I use bear teeth and bacon for bearings cause it's free".

FYI - It's a case hardened "drill rod", exactly the same size as a new cam, not the steel rod you find at home depot. I am of the opinion that bearings live longer when you have 100% of the surface in play.

Richard, The bronze bushing at the rear of the cam needs to be reamed after pressing into the block because it compresses. If you press it in properly and ream it to size in line with the first two bearings, it should be ok.

It is easy to check the rebuilt cam bushings for concentricity between the bore and the outer diameter with a pair of calipers. For each bearing assembly measure the distance between the bore surface to the outer diameter surface of each of the bearing halves at 90 degrees to the split lines. If the distance is the same for each half then the bearing is concentric. If not then the difference between two measurements divided by two is the amount the bearing is out of alignment. For example, if one measurement is .258 and the other one is .246, then the difference is .012 and the misalignment is .006.

Art. Thats easier than spinning the cam. Thanks for the info.

Thunder,
Ken Koopsky and I have stated that if you simply insert the cam into the engine without #3 in place, then manually rotate bearing #2, while holding the cam stationary, you look through the #3 cam bearing bore. Determine that the cam center does not move, [best}, or does it rotate and make a circular motion,[bad machineing]?? If it does not move then you need to deal with a bad bore alignment. However, if ithe cam center rotates while the cam is not turned and the #2 bearing is being turned, the #2 bearing is not bored in the center.

Cripes, this is such a simple way to prove the #2 bearing is OK or NG!!!???!!!

With respect,

Noel

Conversely, If the #1 and #2 cam bearings are kept stationary you can rotate the cam and look for the same motion through the #3 cam bore.
If the cam center doesn't move the cam is NOT bent, If it rotates, the cam IS bent.

Noel. When you speak of the cam bores, are you speaking of the holes in the block, or the possibility of the babbit in the bearing, being off center?

I've checked the rear bushing, by installing the cam, and spinning it. The pilot stays centered, so the cam is straight.

I took Arts suggestion, split the bearings, and measured the distance fron the cam bearing surface, and the outside of the cam bearing. This resulted in a .006 difference in the bearing halves.

Now my question is... Will the cam bearings wear in? Or do I need to resort to some other fix?

A .006" difference means the bearings are not bored true. So the likely reason your third bearing wore is a misalignment of the cam as a result of the cam being cocked at one or both of the first two bearings. If you can find replacement first and/or second cam bearings that are bored true, then your cam will be much closer to entering the third bearing easily and you might not have to resort to floating the third bearing like I did. To answer your question, the cam bearings won't wear in much, if they do, you will likely have excessive clearance. Your remedy is to first replace the first and/or second bearing to get a better feel for how off you are at the third bearing. Then you can decide what to do further. If you can't find better bearings, you'll have to align the third by one of the methods discussed.
The long and short of it is find and the best bearings you can. Then see if the third bearing lines up. If not, either float the bearing or do one of the other fixes mentioned.
Its more work than many realize to get the cam set up correctly. You should consider 1. the trueness of the bearing bores 2. the amount of clearance between the ID of the bearings and the cam journals and 3. the fit of the bearing shells in the block 4. the front and rear clearance on the front bearing, and other stuff like set screw holes in the first two bearings not buggered out and proper mesh of the timing gears. Good luck.

Thunder,
I realized today that the information I gave is true for only one position of the bearing. To determine the maximum out of true position, the bearing walls need to be measured across from each other at several different places around the perimeter of the bearing.

I learned this method of checking the bearings from a friend who was on his third set of rebuilt bearings before he got ones that ran true.

Noel and Kens suggestion for checking alignment is good. In addition to checking the second bearing, the first bearing should also be checked. Either one or both could be bad.

How did you get the new bearings to fit on the camshaft? They don't come ready to use out of the box.

I bought a cam, bearings, shim kit, lifters, and bushing. The supplier fit the cams before sending it.