Cam bearing gone bad

.04 over 302 rebuilt 1 and a half years ago not driven every day parked all winter. Went to put a bigger cam in a my friends MAV and the front bearing look like crap found cam retainer bolts loose.lip on the inside edge muched over oiling hole had high oil pressure all its life 100 psi all the time never came down. I thought it was his gage it was a cheap one. You couldn’t tell it was having problems. Cam gear and dissy gear look great like new. Going to pull the motor and check it out. Very strange never seen this before
[addsig]

How does the journal on the cam look? I have never seen a bad cam bearing, even on a siezed from no oil engine.

IF the journal is bluish and/or worn, check for a blockage in the oil pasage to that bearing.
[addsig]

Thats just it the cam looks great im going to check it to see if its straigt cause it looks good enough to put back in something. No discoloration no scoring same size is the one i was going to put back it in. Ill try and take a picture of it tomorrow and post it here. Oh i pulled it down and took it out and you know how cams turn reeal easy will this one was very stiff to turn. Maybe it just did it and we caught it.
[addsig]

Stiff to turn all the way around, or just at one point like it's bent? If it's all the way, could be that the grinder made the journal too big or the wrong bearing was put in on the front of the engine like a .005 over bearing for a ground down cam journal.

I'd be surprised if it was the bearing journal since they are machined by high-tech high-dollar equipment.
[addsig]

The cam bearing dont even looked used on top and all the brearing look near the same. I put the cam that came out of this into anothere block the i have with good bearing in it cam feels just like it should. Theres nothing wrong with the cam.



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That is strange...

I have always heard that Ford line bored their cam bearings. How much truth there is to that in recent years, I have no idea.

The way the bearing is worn, it would tend to point towards something in the valve train in cylinder 5 or maybe the distributor.

One other possibility is the front hole is bored wrong and is out of line with the others.
[addsig]

All symptoms point to a mis aligned cam bore. Could be a bad bearing that was manufactured too thick on the bottom or even installed with some kind of dirt or spacing under the bearing to cause all that pressure on the bottom of the bearing. Sounds like the cam is okay if it fits in another block just fine.

I'd have a shop reinstall a new bearing and try the "feel" test with the cam to see if the same thing happens and if it does, have the bores aligned.

I did put the cam in this one the first time and only going by what my friend told me that it went in fine so yes we are going to put in new bearings and try again.

I have been down this road before. I have seen all five cam bearings look worse then that after 500 miles. A lesson well learned. Check cam runout. Install new bearings making sure the oil holes line up. Measure the ID of the installed bearings. Measure all cam journals and subtract to figure oil clearance. Install cam and it should spin with 2 fingers. Make sure you dont have valve springs binding at full cam lift. If all that checks out you are good to go. You will find that different brand cam bearings will give you different oil clearance even though they are standard size. Let us know what happens.


Blue Fastback

I had a 460 that the cam wouldnt turn until the heads and crank were torqued. I guess the block flexed enough with the bolts pulling it in different directions to the point where the cam would turn freely. Took a pair of pliers to turn the cam without the crank and heads on it, after bolting everything in and torquing the heads, it spun like it was on roller bearings. Weird, but true.