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Camshaft Bearings - Is this bad?

GSequoia

GSequoia

Everyone says I'm a jerk.
NAXJA Member
Location
Torrance, CA
Noticed something with my cam bearings in the engine I'm gonna put it. Not knowing a whole lot about cam bearings I'd like the smart asses - uh, smart guys to take a look and tell me what they think...Is this normal or should I be replacing the bearings?

cambearing1.jpg


cambearing2.jpg


cambearing3.jpg


Thanks,
Sequoia
 
Most DEFINATELY time to look at changing some bearings. Don't know about the 4.0L, but the Ford 6's use the rear journal on the cam bearing to somewhat meter the oil flow to various parts of the engine. Would hate to see you loose the flow.
 
That's what I was thinking - just wasn't sure if there was some sort of normalcy there (such as some cap or something :dunno:).

How would one go about changing them anyway? The FSM doens't shed any light there (guess I'll just rebuild it while I'm in there ;))

Now the tricky part... Resisting temptation to build a stroker!
 
4.0 bearings have holes that line up with passages in the block to lubricate the cam.

Have your friendly local machine shop install new ones. That particular tool isn't available for rental at AutoZone. ;)
 
Ye-ouch!

What kind of noises did this make, before you took a peek?

Bad? Yeah, camshaft ANYTHINGS are bad. Have you pulled anything else apart, since there's not much running left to this? What did the entire surface look like?

Which lobe was this a picture of? I've seen the front-most or rear-most bearings get shot from outside sources (like too-tight cam chains), but if this wasn't the front or rear-most bearings, then there's something BAD binding in there! I can't imagine a whole camshaft bending so badly that this would be a middle lobe bearing of a camshaft- but I haven't seen it ALL yet.

Suprise me?
 
I've seen this type of bearing failure on engines running real high cam lifts and spring pressures.
 
That would be across the whole cam - those are all different bearings.

It's a Clifford 264 torque cam - don't know about the springs it's running. Timing chain didn't look bad to me...

Rest of the engine looks beautiful with the exception of main and rod bearings - I only say that because I haven't pulled the caps yet.

Don't know about the sounds it was making, I've never ran the engine. From what I hear though it was perfectly fine before.
 
If there seems to be ANYTHING wrong with the cam area, it's time for a change...

A machine shop can do the job for you, or there are several suppliers that have tools to install cam bearings. It's an expanding mandrel on a long screw ram, and the bearings are pulled into place. Often, the same tool can install and remove bearings. Check the price of the tool against the cost of having the bearings replaced at a shop, factoring in your time hauling the thing there and back.

It's not difficult to replace the cam bearings (you'll want to change the welch plug behind the camshaft while you're about it, since you'll knock it out to access the rearmost bearing,) but as has been mentioned, MAKE DAMN SURE the oil holes are lined up - or you just wrecked the cam. Also, don't be stingy with the assembly lube - too much is almost enough...

For the tools, check with Crower Cams, Crane Cams, Goodson, Summit, Jeg's, or anyone like that.

5-90
 
Okay, according to Dr. Dyno's page the OEM valve springs are rated for 0.430" valve lift max. The Clifford 264 cam that's in that engine lifts at 0.474".

I'm thinking maybe those valve springs are OEM, won't handle the lift, the cam bound and spat the bearings out, sound plasable?

Again according to Dino's page there are Mopar Performance springs that will handle half an inch of lift plus (don't remember exactly) and will sit on the stock spring seat; soundns like a good way to go when I put this back together.

I am still going to rebuild the engine while I'm in there (It's gotta go to the machine shop anyway); all I gotta do now is talk myself out of stroking it.

Sequoia
 
Check the Crane catalogue, or maybe Schneider Racing Cams - I think they both have springs and rockers that will handle up to about .500" of lift (remember that cam lift and valve lift are two different things, tho - cam lift can be restricted by the length of the slot in the rocker, and valve lift can be restricted by the valve spring "going solid" - also called "spring binding," this is where the spring is compressed to the point where the wire coils run into each other.)

Typically, restricted lift results in bent pushrods - have you checked those yet? You'll probably want a set (and I'd go and put in a set of Rhoads lifters - I always did like those in HP engine buildups! I don't remember the Rhoads part numer prefix, but the number part is 2011.)

5-90
 
Another question...

Do oversized camshaft bearings exist? I'm just wondering if the shaft is slightly scored can I have it machined flat and use an oversized bearing?

Also if it's badly scored can I grind it down and just fill the score with Bondo? :twak:
 
That's something I'd have to check on - they're about as common as feet on fish. Typically, cams are not reground to fit new bearings. Replacement is easier.

Also, if the journals had to be filled, you'd do a "weld and grind" rather than just some sort of filler. Fusion is critical here...

5-90
 
I talked to Larry at Clifford and showed him the pix. He says the engine didn't have the spring loaded cam preload in the timing chaing cover and the cam was walking back and forth.

Check it.
 
Funny... Larry is who I've spoken to as well.

By spring preload you mean the little pin and spring in the hollow cam sprocket bolt? If so then yes it does have that...
 
He said if the cam is screwed, he would cut you a super deal on a replacement, but he also said, it rarely hurts the cam. The 'Clifford springs have an outside diameter of 1.44" and have a damper. Look and measure and you should be able to tell if you have their springs. By the way, their springs are really only for the 258 head not the 242.
 
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