390 build - failed cam bearings

[JAKES66]

** Edit:  It's been a couple years since I've assembled an FE engine and can't remember how I oriented the bearing oil holes in the past.  It appears this time that the culprit was the oil hole facing upward away from the load on the camshaft by the lifters, but perhaps there is another problem I'm not seeing?  Thanks for your input!  Build details are below:**

1972 391 block w/ Precision Oil Pump distributor bushing, .030 over forged pistons, 3.78 stroke, C7 rods w/ ARP bolts, Mellings HV pump, homemade laterally flared semi-deep front sump pan, D2 heads w/ home port job and CJ SS valves w/ teflon seals, Comp 294S K-kit, factory adjustables w/ Crane adjusters and Doug's Precision Oil Pump end stands

Engine destination is a 66 Galaxie 500XL w/ HEH-CC toploader and 3.70 trac-lock 9" for street/strip

Started the engine with only a slight amount of drama on my awesome home-built test stand.  Cam break-in seemed to go rather well despite one shut-down to rig up a fan for more cooling air flow.  Oil pressure held steady at approx 75 psi at speed (1800ish RPM) dropping to around 40 at idle hot.  Comp Cams break-in oil was used as well as Comp's cam and lifter installation lube on all the cam lobes, lifters and distributor gear.

After shutting the engine down I cut the oil filter open and to my horror I found fine metal shavings... a lot of them.  The engine probably had 1 hour of run time with only the outer valve springs and dampers installed.  Upon disassembly, I fear I have made a critical error.  See the picture below.  Have I installed the cam bearings up side down?!!

Of course I'm ordering new bearings as the old bearings are toast.  Should I just replace, clean and reassemble?  Could upside down bearings really do this?  What would you do?

[jayb]

I can't say I've ever installed them like that, so I'm not sure if that would cause the problem you saw or not.  But for sure putting the hole down is the preferred way, and in fact I think that clocking the hole in the bearings at the 4 o'clock or 5 o'clock position (as viewed from the front of the engine) is probably the best position.  It sounds like you did everything else right.  Did you pre-oil the engine, and get good oil pressure when you pre-oiled?

I think if it was me I'd clean all the oil galleys out, double check everything, and if it all looked good, put it back together with the holes facing down and try again.

[blykins]

Yep, turn 'em down.  I could see how you would have no oil support towards the bottom of the cam journal if all the oil was coming in from 12:00. 

Every side oiler and every aftermarket FE block lived/lives just fine with the bearing holes lined up at the 6:00 position.  Sometimes I will clock them at 4:00-ish position, but I continue to wonder if it's necessary at all. 

Make sure your cam spins freely in the bearings when you install it. 

[JAKES66]

Great info, thanks for the replies.  I was able to pre-oil the engine for maybe a minute before firing using an old distributor shaft and a hand-held drill.  It made 75 psi with cold oil and making sure all the rockers were getting oil with the covers off.  It wasn't long and I had a mess to clean up!    Apparently the drainbacks are overcome easily even with .060 restrictors in the rocker feed passages.    Luckily the cam rotated freely during assembly so no scraping/clearancing of bearings was necessary.

I've got a set of King bearings on the way.  I'll reassemble with the new bearings at 6:00 and give it another try.

Thanks again for your help.  It sure helps the confidence factor.

[Barry_R]

Should not have caused the problem.
Not certain about King, but all others with the single exception of ACL use Durabond for cam bearings - - they are all the same inside of the box...

[cammerfe]

As part of the oiling mods to my current 390, I put in a set of roller cam bearings. I used Ford Performance bearings listed for a 385 block. Luckily they're the same as far as cam diameter is concerned---simply making necessary the use of a steel (roller) cam. We bored the cam tunnel out to the 460 size and re-grooved for the oil around the backside of the bearing races. Since the rollers are oiled by splash, the current set-up directs ALL the oil right to the crank without the bleed-off at the cam journals.

KS

[JAKES66]

Should not have caused the problem.
Not certain about King, but all others with the single exception of ACL use Durabond for cam bearings - - they are all the same inside of the box...

The cam journal surfaces look really good, clean and smooth - almost polished.  Just like you'd expect to see out of a good running engine.  Nothing else noteworthy about the break-in.  All the connecting rod and main bearings look fine. 

I did, however, notice that the rear-most cam bearings looked worse than the front, although I haven't yet removed them.

[Jason R]

Jakes66 after reading this I was looking close at my "105" block that I am just starting to put together, and it seems like an easy mistake to make. The ref book I am using is Steve Christ how to rebuild BBF only mentions lining the  oil hole in the bearing with the oil passages in the block. On the # 1 cam bearing that's easier because there's two holes in both the bearing and two in the block to match. But as you all know on #2-5 there's a hole at 12 o'clock from the galley and one at 6 o'clock headed to the mains with the channels all around those last four and only a single bearing hole. For me putting an FE together only occasionally this has left me a little confused before. It surprises me that the pressurized feed at 12 couldn't carry enough oil around to the loaded side at 6 to protect the cam and bearings for the short duration you ran it. I guess a new tight motor and those valve springs are still enough force to break through that oil film?
 On your #1 cam bearing was it in with holes at 12 o'clock and like 3 o'clock which would block any flow at all from getting to it or the distributor bushing or was it in correct with holes at 6 o'clock and 9 that gives it full flow. I ask because it's different than the others and if it was in correctly the #1 cam bearing should be good unless something else in the motor was wrong? I don't mean to be a PITA but this is one of those threads that's worth it's weight in gold for guys like me who can learn from someone's experiences.
Thanks,
Jason

[Jason R]

Sorry guys I messed that up, I was looking at my block upside down!
    3 o'clock and 6 o'clock would be correct for the oil hole locations for the #1 cam bearing looking at the front of the block.
Jason

[C6AE]

I have installed them with the holes up once... They failed in the same manner. There was another similar failure a few months ago on the other forum.
(In my case it was a mistake, I know better but rolled the engine on the stand after installing each end and installed the three center bearings exactly wrong.
(There is quite a bit of internet noise about the "dynamic wedge" but I think the science comes more from splash oiling or gravity oiling than with a fully pressurized system,  the cam moves with rpms creating a slight wedge with the holes at 6:00. If you put the holes "up" in the bearing clearance you just generated a local loss in oil pressure).
The side oiler blueprints are specific, holes at 6:00. I'm surprised there are no blueprints out there for a center-oiler.
Jake R

[john a]

My cam bearings failed as well, even though they were installed correctly. Never did figure out why, some suggested just a bad set of bearings.

[JAKES66]

My cam bearings failed as well, even though they were installed correctly. Never did figure out why, some suggested just a bad set of bearings.

Wow John, that's interesting(scary).  Did the engine do OK on the second set of bearings?

I'll take some more pictures later this week after I get the bearings out.  Gotta run over to dad's place and get the installer this evening...

I very well may have rolled the block while inserting bearings.  I usually to go in from the back of the block with the installer to do the front bearing, then from the front to finish the rest. 

[john a]

My cam bearings failed as well, even though they were installed correctly. Never did figure out why, some suggested just a bad set of bearings.
[/quote]
Wow John, that's interesting(scary).  Did the engine do OK on the second set of bearings 


I hope so, I only have about 200 miles on it. With the first set of bearing I noticed over time the oil pressure going down, so far with the second set the oil pressure is staying up where it belongs.

[Falcon67]

FWIW - we 351C types have been known to install the cam bearings upside down, then drill in from the mains with a .040 drill.  A trick that simulates restrictors without tapping the oil passage.  But it requires a trick drill bit to reach.

[JAKES66]

OK, here are pictures of the bearings removed.  #1 bearing looked the best since it was installed correctly, #2 thru #5 looked pretty rough although some more than others - all (4) of these bearings were installed incorrectly with the oil hole at 12:00.

**Edit - Added photos instead of link**