Cam bearing problem

[tommytt]

HELP
I will be pulling my engine out for the 4th time in a year and never with more than 10 minutes break in time.  The cam bearings are being crushed, like putty, on the bottom half of the bearing.
427 original side oiler, 671 blower, Hilborn mechanical injection in a '57 Ford ranchero Gasser. Runs low 10's.
I ran the car for 8 years with no problems.  A little over a year ago I hurt the thrust bearing so I pulled the engine for crank repairs.
Okay.  Here's my changes, while I had it out, so I'm guessing one of these is my problem. 
I took the 427 standard irons heads off.  They were ported and set up nicely with stainless PRW rockers etc.  I replaced them with BBM heads that were CNC'd to flow about 360 CFM on the intakes.  The open spring pressure was 750 ish and closed 350 ish.  I did, later on my 3rd attempt to get the cam bearings to live, reduce the spring pressure by about 125 open and closed.  I have Harland Sharp full roller rockers.
The other change I did was to install an Isky solid roller cam with their best rollers.  I do have a blue printed HV oil pump.  Also 3 different sets of Manton push rods were tried to get the best pattern on the top of the valve.  I don't see anything that is binding.
The BBM heads and Isky cam set up were there from the 1st build, a year ago, and on thru all these problems.
Things I have done to try and fix this major headache and body aches too.  I've had the car since 1962 (not a typo) and pull and build the engines myself.  I'm tired of lots of work and no pleasure!
Sorry I got distracted.   I have had 2 different "Hi-Perf" machine shops change cam bearings each rebuild.  They tried a couple different brands.
The last time the shop even went in behind the bearings, 2 & 4, and cut a groove connecting the 2 oil feed holes.  We were worried that the smaller groove in 2 & 4 journal on the Isky cam was not deep enough.  Also the time before they even enlarged the 2 cam grooves on 2 & 4.
I also restricted the oil passages to the lifters because it is a later 427 block drilled for hydraulics.
When I test the oil pressure, on the engine stand, oil flows everywhere.  When in the car it starts out at 100psi, but again with maybe 6 minutes running time, the pressure goes down to 5psi.  I pulled the valve covers, to check the lash, which I had set at .025", and it is now .060" so I know the cam bearings are crushed again.
Sorry for rambling on but I really need some thoughts.
Tom T

[fastf67]

I'm no expert for sure and you will have plenty and better to chim in, and sorry to say but need more information. Need cam part number and specs. Blower you say, compression, timing? How much feeler gauge are you able to get in the spring coils at full open. At (750ish) open pressure it must be a large cam and I'm sure you would have noticed marks on the pistons, do you know the clearance? Do you have the plug in behind the dizzy? Valve train oil restrictor size? If these things are good and there is no binding in any of the valvetrain (push rods, lifters are not to tight in the bores, rockers on the shaft, rockers to the spring interference, valve stems in there bushings? With strong push rods bearings could give out first if just a little tight in tolerance as parts can be harder to move under pressure. It's strange but so is your problem thou. About the only thing left would be the finish on the bearing journal on the cam Itself. Real odd things i guess could be a timing chain or gear drive so tight wiping out the front cam bearing with the rest to follow, something moving in a oil passage that's stopping flow when under pressure (more then a drill) or a pipe plug threading so deep it's restricting? Some off the wall stuff but could be possible I guess. Your tear down inspection needs to be methodical. Sorry to hear your problems and please tell us your findings.  Mike

[blykins]

Enlarging and cutting grooves does nothing (unless you are grooving behind the bearing and drilling the bearing for multiple oil feeds), and if anything, is exacerbating the problem as you are taking oil away from the cam bearing and handing it to the rockers.   The grooves on the 2 & 4 journals are for supplying oil to the cylinder head feeds only.   On a center oiler block, the groove is behind the bearing and feeds the heads.  On a side oiler, the groove is in the cam journal as there are no feeds behind the bearing. 

Unless you are having lifter failures (I would also check that), then here's what I would recommend:

1.  Check for missing gallery plugs, bleeding off pressure.
2.  Check for valve spring coil bind. 
3.  Upgrade to a wider, coated cam bearing. 
4.  Check the cam bearing clearance, like you would a main or rod bearing.  350 lbs seat pressure is probably WAY more than you need, but high spring pressures will cause the cam to wipe the bearing.  Some guys will just stab a cam in and if it will turn at all, they're good.  However, with higher spring pressures, you need oil clearance, just like a regular bearing.  I will run .002-.0025" clearance as measured. 


What's your oil filter look like?  Are you doing oil changes and filter checks?  With that much material lost off the cam bearings, you would be seeing all kinds of metal in the oil. 

[Barry_R]

He said a side oiler, so connecting the oil feeds in the block is a legit modification if he was not getting enough oil flow to the rockers - but it won't help a cam bearing problem.
There are only a couple "real" cam bearing manufacturers out there, and minimal actual materials variation - I honestly don't think a manufacturer change is likely to cure the problem.
The 100 psi cold start oil pressure almost completely rules out a missing galley plug (almost...), when we miss a plug we'll see maybe 40/50 on the pre-oil drill instead of 70-75...

My bets would be on (in no particular order):
Mechanical Valvetrain interference
Hydraulic lockup from the injector system
Cracked block between main and cam (these can be really hard to see sometimes)

You can have operating valvetrain interference even though the engine turns over and measures OK - - stuff moves and what looks and feels safe can make contact in operation.  I got caught on that a while back working on an OEM high riser head deal.  Valve seals looked OK to the eye, cam was one that we've run dozens of times with no issue, and everything turned nice and easy.  Engine ran fine, but post dyno inspection found that it had kicked the little garter springs off of several of the seals.  Turned out that the valve guide bosses on an unmodified factory high riser head are taller than they are on any more common FE heads, and we had barely enough clearance to turn free - until it ran at 7000 - then we had not enough.

[blykins]

Retainer to seal/guide clearance is a good one to note. 

[jayb]

My first thought after reading this was a cracked block, with the likely area the oil passage between the #2 or #4 main and the cam bearings.  The reason I think that is because the oil pressure drops so dramatically after a few minutes of running.  As the block heats up, those cracks (which are nearly invisible) will open up, releasing more oil.  Lack of oil could be causing the cam bearing wear.  How are the main bearings, are they showing some excessive wear also?

Piston to valve clearance is also a potential issue, although I'm not sure that it would explain the rapid loss of oil pressure.  Are there any signs of valve contact to the pistons after teardown?

[My427stang]

Every bit of the information here is worth looking at.  I have seen a few melted cam bearings on FEs over the years and it was always due to someone not checking clearances and/or hammering in a soft bearing with the tool too loose or mandrel not seated properly.

I have not seen what Barry saw about brands, in fact, although there are likely few, I bought 3 sets last summer to look at them and saw a big difference.  Believe it or not, the nicest bearing IMHO right now, for cam bearings only, is made by ACL for Enginetech.  It is noticeably stronger and seems more durable, drives in normal.  Durabond would be next, and the ones I won't even use unless I absolutely have to are FM.

I don't know what changed over the years, and I have never seen a failure in a set I fit, but as a young diesel mechanic in the 80s and 90s, I would beat those bearings in without any care in the world, and they would always fit nicely.  Now, they seem fussy to me and I take great care cleaning the bores, fitting the mandrel and even then, other than the Enginetech, I believe they'd rather be pulled in than driven in

I know the Enginetech seems cheap, even liking them, I tend to use Durabond for the name, but they don't make anything anyway, take a look at a set, then look close at all your clearances,etc. 

[blykins]

I’d also like to know if he’s losing all the cam bearings or just one or two.  That would narrow down the diagnosis.

[jayb]

Another question: are the cam bearings spun, or are the oil holes still lined up when they've failed?

[My427stang]

I’d also like to know if he’s losing all the cam bearings or just one or two.  That would narrow down the diagnosis.

My first thought after reading this was a cracked block, with the likely area the oil passage between the #2 or #4 main and the cam bearings.  The reason I think that is because the oil pressure drops so dramatically after a few minutes of running.  As the block heats up, those cracks (which are nearly invisible) will open up, releasing more oil.  Lack of oil could be causing the cam bearing wear.  How are the main bearings, are they showing some excessive wear also?

Piston to valve clearance is also a potential issue, although I'm not sure that it would explain the rapid loss of oil pressure.  Are there any signs of valve contact to the pistons after teardown?

Yes and yes.....very good idea on potentially dumping oil, and equally good point to see if it's the same bearing or bearings every time

[Stangman]

I’d also like to know if he’s losing all the cam bearings or just one or two.  That would narrow down the diagnosis.

I had #4 getting beat up  enough that it was hard to get out of motor because groove on cam was grooving cam bearing. It ended up being 2 rocker arms that were tight and when hot you could barely move them. The last three rockers slid off the shaft and I just put them back on must have mixed up shims. After I found it it never happened again. Motor ran fine and it took 2 months for this to happen but don’t overlook it you did put new rockers on.

[tommytt]

Guys,  Barry, Brent, Mike, Ross, Jay and others,
Thank you, Thank you, Thank you for your replies.  I have read every one.
I'll go through the clearances I have triple checked which makes me lean toward a cracked block or something really odd.
Piston to valve, about .250" because of 8-1/2 to 1 comp for blower.  Retainer to valve seal 1/4" at open and also spring coils, inner and outer about a 1/4" at open.  Spring pressure is now down to 625lbs ish and 225lbs ish closed.  Timing gear to cam plate about .008".  I didn't measure cam bearing clearance to cam, as a few of you mentioned, but it felt great, turned freely, and the machine said that it was good when they installed the cam bearings (3 diff times) and 2 diff shops.  You're right I should have rechecked this myself especially with all the problems.  Also rods and mains are both at .025" with a steel Ford crank.  All rod and main bearings look great on tear down and very little metal in filter.  Cam bearings are just crushed but not worn like a bearing would like with a 1000 mile problem. Rockers move freely and have needle bearings where they contact the rocker shaft. I sat the valve covers back on, not bolted down, and put hand pressure on them to see if rockers were hitting the inside of cover. No contact and no signs of or marks inside of covers.  Great thoughts on cam bearings. NOT spun and holes still line up.  Middle 3 showed MORE damage than end 2.  First set were ACL then 2nd and 3rd sets from diff machine shop were different brand. I should of asked but they were not ACL.  I didn't want to get into the 1st tear down problem but it was no oil to rockers. OK if I have room I'll explain. The lifters I had in the car, for 40 years, were Ford shell flat tappet lifters which prevented oil from going through the lifter galleries. They have no wide groove on the outside of the lifter. When I switched to the Isky roller cam, a year ago, the new Isky solid rollers have the big oil groove, on the outside of the lifter, which killed the oil pressure to the rockers. Ruined 4 rockers, which I replaced and I thoroughly checked all others. I have since then restricted the oil flow by 90% through the 2 lifter galleries. Brent you questioned why I spent time on getting more oil to the rockers. This is why. I probably shouldn't have brought this up but it is fixed now and when I power the oil pump, with my air ratchet, oil flows very nicely through the rockers. I get 40 PSI driving the pump this way.
Back to my real problem (cam bearings).  I have a spare brand new, never used, 427 bare block.  I have been saving it (for what??). Maybe now!  Also I think one of you mentioned a cam bearing that was a little wider. What brand??
I hope I have answered all your questions on clearances and checks.  If you see something I mentioned that doesn't sound right let me know.
I can tell you are all VERY knowledgeable regarding the FE motors.  I have a few good years left doing what I love, which is building and racing the Ford FE.  There is definitely not a lot of us out there.
I did post on YouTube a video of some of my build.  I feel maybe I shouldn't have because of all my failures.  If you want to see it it's listed under "427 Ford FE Engine Building Tips 10-2019" Tom Tucker   If you spot some mistakes let me have it.  I'm ready to except my mistakes.
I know this was long but I'm desperate.   Tom T

[67xr7cat]

Hi,

Do you have pictures of the failed cam bearings? Thx Steve

[WConley]

Have you looked at setting the valve springs at .050" from bind at full lift?  A quarter inch is way too much.  Setting the springs tight will allow you to knock a lot more spring pressure off while still keeping the valvetrain in control. 

Your cam bearings will thank you!

[blykins]

Guys,  Barry, Brent, Mike, Ross, Jay and others,
Thank you, Thank you, Thank you for your replies.  I have read every one.
I'll go through the clearances I have triple checked which makes me lean toward a cracked block or something really odd.
Piston to valve, about .250" because of 8-1/2 to 1 comp for blower.  Retainer to valve seal 1/4" at open and also spring coils, inner and outer about a 1/4" at open.  Spring pressure is now down to 625lbs ish and 225lbs ish closed.  Timing gear to cam plate about .008".  I didn't measure cam bearing clearance to cam, as a few of you mentioned, but it felt great, turned freely, and the machine said that it was good when they installed the cam bearings (3 diff times) and 2 diff shops.  You're right I should have rechecked this myself especially with all the problems.  Also rods and mains are both at .025" with a steel Ford crank.  All rod and main bearings look great on tear down and very little metal in filter.  Cam bearings are just crushed but not worn like a bearing would like with a 1000 mile problem. Rockers move freely and have needle bearings where they contact the rocker shaft. I sat the valve covers back on, not bolted down, and put hand pressure on them to see if rockers were hitting the inside of cover. No contact and no signs of or marks inside of covers.  Great thoughts on cam bearings. NOT spun and holes still line up.  Middle 3 showed MORE damage than end 2.  First set were ACL then 2nd and 3rd sets from diff machine shop were different brand. I should of asked but they were not ACL.  I didn't want to get into the 1st tear down problem but it was no oil to rockers. OK if I have room I'll explain. The lifters I had in the car, for 40 years, were Ford shell flat tappet lifters which prevented oil from going through the lifter galleries. They have no wide groove on the outside of the lifter. When I switched to the Isky roller cam, a year ago, the new Isky solid rollers have the big oil groove, on the outside of the lifter, which killed the oil pressure to the rockers. Ruined 4 rockers, which I replaced and I thoroughly checked all others. I have since then restricted the oil flow by 90% through the 2 lifter galleries. Brent you questioned why I spent time on getting more oil to the rockers. This is why. I probably shouldn't have brought this up but it is fixed now and when I power the oil pump, with my air ratchet, oil flows very nicely through the rockers. I get 40 PSI driving the pump this way.
Back to my real problem (cam bearings).  I have a spare brand new, never used, 427 bare block.  I have been saving it (for what??). Maybe now!  Also I think one of you mentioned a cam bearing that was a little wider. What brand??
I hope I have answered all your questions on clearances and checks.  If you see something I mentioned that doesn't sound right let me know.
I can tell you are all VERY knowledgeable regarding the FE motors.  I have a few good years left doing what I love, which is building and racing the Ford FE.  There is definitely not a lot of us out there.
I did post on YouTube a video of some of my build.  I feel maybe I shouldn't have because of all my failures.  If you want to see it it's listed under "427 Ford FE Engine Building Tips 10-2019" Tom Tucker   If you spot some mistakes let me have it.  I'm ready to except my mistakes.
I know this was long but I'm desperate.   Tom T

Thanks for the reply....

So which rocker do you have extra lash on and is it the only one?