2nd wiped Camshaft OMC 460

[Trevthefox]

Hey guys! Yeah its as bad as it sounds. At this point I'm just trying to figure out what is causing this problem. Bear with me on this long story and please help!!

Backstory: Originally pulled engine to address a transom leak. While engine was out we figured we should do a once over and take it apart to see the condition of it. Having extra time during quarantine we decided to change some components: new cam, main, and rod bearings. New piston rings. We also re-lapped the valves and replaced the valve stem seals

Our mistake was not checking the lobe lift on the original cam and we replaced the lifters. We did an improper break in and ended up hearing some crazy rattling coming from the valve cover. Upon inspection we noticed a rocker arm was really loose on while the valve was closed. We took out the lifter and it was shaved off at a slant pretty bad. We wiped the lobe. Just this week installed a brand new cam from comp cams. Made for a marine 460. It wasn't an exact match but had a little bit of a higher lobe lift. When installing we did followed all instructions perfectly: comp cams break in lube, zinc additive, primed oil, oil was coming out of each rocker arm just fine. She started up right away and it sounded amazing. Got it up to 2500 rpm immediately. About 8 minutes into the break-in process we heard a rattle but it corrected itself almost immediately. Then it started to rattle more frequently but still intermittent. Cut the engine to think about it, and then decided to resume. At the 10 minute mark we went up to 2800 rpm and the rattling continued. Heard it coming from the valve covers. We decided to stop. After cooling down, we removed valved cover and intake manifold. The same lifter in the same lifter bore is shaved at an angle again. Lobe is probably wiped again. I couldn't even remove the lifter.

So what's going on? My conclusions are obviously the lifter isn't spinning if the lobe its wearing the lifter at an angle. Oil pressure was good so i'm pretty sure it was getting oil. Could it be a bad valve? Just a bad lifter bore? I'm lost. Machine shop is recommending just get a new block if we're having the same problem. I just don't want to get a new block and put the same heads on it and end up with the same problem.

 

[alldodge]

My thought is the one lifter is not getting enough oil. Oil drips off the lifter to the lobe.

Did you deep clean the block?

 

[gm280]

Odd for sure. Have you checked the valve and valve spring pressure? And have you checked to see if the lifter bore is good and perpendicular to the cam lobe. And is there any chance the rocker stud is not coming out of the block? Are your lifters solid, hydraulic, or roller?

 

[Scott06]

Check for adequate oil supply, use priming tool to run oil pump with valve covers and intake off.
You say the lift is more - did you check for valve seal to retainer clearance? When you replaced the seals were the valve guides remachined for the seal used if a more modern positive seal was used? If so you can run into seal to retainer interference. If you are running a non stock cam I would check this and installed valve spring height.

I had recently gone through this on my 65 GTO. I had valve job done years ago, machinist installed teflon seals. For some reason he machined the exhaust guides .095" taller than the intakes. My stock cam was hitting the seals. I had some wear on the rocker tips from this. A few of the isntalled spring heights were tall by as much as .070"

 

[Trevthefox]

My thought is the one lifter is not getting enough oil. Oil drips off the lifter to the lobe.

Did you deep clean the block?

The initial removal yes we cleaned it pretty good. Pressure washed and compressed air but we did not hot tank it. The 2nd removal we just changed the oil and filter. Wasn't the smartest decision but both times led to the the lifter/lobe failure.

 

[alldodge]

Same lifter both times would tell me its the block

 

[Trevthefox]

Odd for sure. Have you checked the valve and valve spring pressure? And have you checked to see if the lifter bore is good and perpendicular to the cam lobe. And is there any chance the rocker stud is not coming out of the block? Are your lifters solid, hydraulic, or roller?

The valves move freely but I have not checked the spring pressure.

I did eyeball the lifter bore and it seemed be good but in hindsight I don't know for sure. There were no visible burrs or any I could feel neither. But I now I want to check lifter clearance because it can't be a coincidence that it keeps happening to the same lifter.

My lifter's are hydraulic flat tappet.

When you say the rocker stud are you referring to the bolt that tightens it to the stud? Because that held toque. The rocker had side to side play when the lobe was on the "closed" end and that was the rattling I was hearing. When I removed that bolt it was still torqued down.

 

[Trevthefox]

Check for adequate oil supply, use priming tool to run oil pump with valve covers and intake off.
You say the lift is more - did you check for valve seal to retainer clearance? When you replaced the seals were the valve guides remachined for the seal used if a more modern positive seal was used? If so you can run into seal to retainer interference. If you are running a non stock cam I would check this and installed valve spring height.

I had recently gone through this on my 65 GTO. I had valve job done years ago, machinist installed teflon seals. For some reason he machined the exhaust guides .095" taller than the intakes. My stock cam was hitting the seals. I had some wear on the rocker tips from this. A few of the isntalled spring heights were tall by as much as .070"

I did use the priming tool and it seemed to get adequate oil to every bore. I will have to check again to see if the bad bore gets less that the others.

The valve seal to retainer was good. Plenty of clearance and no coil bind neither.

When I did the valve job myself one head had the positive seals and the other had the umbrella style. I replaced both with the positive seals but there were different sizes which obviously told me that some work was done on one of the heads and I bought 2 different sizes of seals to account for it.

 

[Scott06]

Did u machine the guides on the heads for the positive seals? Sounds like you have some mix and match parts tough to tell what was done previously.

if i recall on ford 429 and 460 heads the pushrod length is changed to account for any machien work like milling the heads etc? Might want to look at this angle. Im not knowledgable on fords but im sure there is info out thee
you must a valve train geometry issue or an oil passage blocked somewhere as you are not getting oil if you cant get through break in

 

[Trevthefox]

Did u machine the guides on the heads for the positive seals? Sounds like you have some mix and match parts tough to tell what was done previously.

if i recall on ford 429 and 460 heads the pushrod length is changed to account for any machien work like milling the heads etc? Might want to look at this angle. Im not knowledgable on fords but im sure there is info out thee
you must a valve train geometry issue or an oil passage blocked somewhere as you are not getting oil if you cant get through break in

I didn't have any work done on the heads myself. The heads came the way they are. However its obvious the engine had some work done on it previously. Cylinder is bored 40 over and when I was doing the valve job I noticed one head had positive style seals and the other had umbrella. I was just going to reuse what the head already had but someone convinced me to replace all the seals since i had it apart and to go with positive seals. When I bought the replacements I noticed that the new seals didn't fit on the head that had the umbrella style. So I measured the valve guides with my micrometer and bought the positive style that fit. I wonder if that what was causing the problem.

Is that posible?

 

[Scott06]

I didn't have any work done on the heads myself. The heads came the way they are. However its obvious the engine had some work done on it previously. Cylinder is bored 40 over and when I was doing the valve job I noticed one head had positive style seals and the other had umbrella. I was just going to reuse what the head already had but someone convinced me to replace all the seals since i had it apart and to go with positive seals. When I bought the replacements I noticed that the new seals didn't fit on the head that had the umbrella style. So I measured the valve guides with my micrometer and bought the positive style that fit. I wonder if that what was causing the problem.

Is that posible?

yes Its possible. When you change out to positive seals you need to machine the valve guides down so the seal will fit. If you just put a seal on top of the cast in boss i would suspect you have seal to retainer interference , could be hitting the inside if the spring as you are likely using a seal too big in diameter. This video shows cutting guides for positive seals at about 10:00 in.

. The cutters for this are about $100 they have an arbor that goes in the valve guide so you can do it with a drill. You can check with the head on just need a spring compressor that screws into rocker stud and put air in cylinder to hold the valves up.

you checked the seal to retainer clearance? You need valve lift plus .050 or .060” depending on who you ask . Check like this document shows https://blog.dartheads.com/how-to-set-up-a-cylinder-head

its also entirely possible the heads and or block were milled to make them flat during a rebuild. I don't think the rockers are adjustable on a stock 460, just torque to spec, you should verify this or convert it to adjustable so you can set zero lash.
in short id verify the valve seal to retainer possible interference, oil flow to that lifter, and look to either verify the geometry is correct or go to an adjustable set before putting another cam in.

 

[Scott Danforth]

Fords need custom length pushrods or convert them to adjustable valvetrain and run GM rockers

If the lifters do not get enough oil they eat themselves. Time to check the oil passages on the lifter bores

Cam breakin is 2000rpm for 20minutes

Improper sesls could cause coil bind

 

[Scott Danforth]

Fords need custom length pushrods or convert them to adjustable valvetrain and run GM rockers. for those that know the 470 platypus motor. same thing. Just like Mopars. if the head is milled, or the deck is milled or a valve job done on a Ford, new push rod lengths are required.

If the lifters do not get enough oil they eat themselves. Time to check the oil passages on the lifter bores

Cam breakin is 2000rpm for 20minutes

Improper sesls could cause coil bind

 

[alldodge]

TV, Phone sll re things that work pretty well around cities, go rural and things don't work as well like no local. Some have tried CC hear and say it works but its spoty and worst the ATT. Bluegrass works best but they were just bought out by Verizon, which was no to good, but guess now they will be better

 

[Scott Danforth]

TV, Phone sll re things that work pretty well around cities, go rural and things don't work as well like no local. Some have tried CC hear and say it works but its spoty and worst the ATT. Bluegrass works best but they were just bought out by Verizon, which was no to good, but guess now they will be better

Hey AD, cross-posts?

 

[alldodge]

Hey AD, cross-posts?

Woops

 

[Trevthefox]

yes Its possible. When you change out to positive seals you need to machine the valve guides down so the seal will fit. If you just put a seal on top of the cast in boss i would suspect you have seal to retainer interference , could be hitting the inside if the spring as you are likely using a seal too big in diameter. This video shows cutting guides for positive seals at about 10:00 in.

. The cutters for this are about $100 they have an arbor that goes in the valve guide so you can do it with a drill. You can check with the head on just need a spring compressor that screws into rocker stud and put air in cylinder to hold the valves up.

you checked the seal to retainer clearance? You need valve lift plus .050 or .060” depending on who you ask . Check like this document shows https://blog.dartheads.com/how-to-set-up-a-cylinder-head

its also entirely possible the heads and or block were milled to make them flat during a rebuild. I don't think the rockers are adjustable on a stock 460, just torque to spec, you should verify this or convert it to adjustable so you can set zero lash.
in short id verify the valve seal to retainer possible interference, oil flow to that lifter, and look to either verify the geometry is correct or go to an adjustable set before putting another cam in.

I'll check that today. thanks for the reply. I did confirm that its definitely the head where I changed the umbrella seals to positive seals

 

[Trevthefox]

Fords need custom length pushrods or convert them to adjustable valvetrain and run GM rockers. for those that know the 470 platypus motor. same thing. Just like Mopars. if the head is milled, or the deck is milled or a valve job done on a Ford, new push rod lengths are required.

If the lifters do not get enough oil they eat themselves. Time to check the oil passages on the lifter bores

Cam breakin is 2000rpm for 20minutes

Improper sesls could cause coil bind

So I just pulled part the motor last night. Oil passages are very clear. They look super clean and I can see from from the front where the oil galley plug is all the way to the back of the engine. Since the lifter affected is Cylinder 7 intake if there was some type of blockage that would mean cylinder 8 intake and exhaust wouldn't be getting oil neither since they're in line with each other. I also checked cam end play which is within specs.

I also spun the camshaft to watch the lifters. The one that keeps eating a lobe is spinning the lifter just fine. There however are some burrs and scratches in that bore but pretty minor and they might be from when we removed the lifter since it was coned out it was tough to remove it. But that being said, it is spinning.

See attached pic of the bad lifter. This lifter was obviously not spinning. Very slim chance I had 2 bad lifters in the same bore causing issues. So that leads me to believe its a valve issue like some of you are suggesting.

I am going to check that lifter bore clearance. Maybe it has too much and it Wiping away oil.

 

[Trevthefox]

Fords need custom length pushrods or convert them to adjustable valvetrain and run GM rockers

If the lifters do not get enough oil they eat themselves. Time to check the oil passages on the lifter bores

Cam breakin is 2000rpm for 20minutes

Improper sesls could cause coil bind

Just checked pushrod length. They fall within specs that the manuals gives after the clearance check.

 

[Trevthefox]

yes Its possible. When you change out to positive seals you need to machine the valve guides down so the seal will fit. If you just put a seal on top of the cast in boss i would suspect you have seal to retainer interference , could be hitting the inside if the spring as you are likely using a seal too big in diameter. This video shows cutting guides for positive seals at about 10:00 in.

. The cutters for this are about $100 they have an arbor that goes in the valve guide so you can do it with a drill. You can check with the head on just need a spring compressor that screws into rocker stud and put air in cylinder to hold the valves up.

you checked the seal to retainer clearance? You need valve lift plus .050 or .060” depending on who you ask . Check like this document shows https://blog.dartheads.com/how-to-set-up-a-cylinder-head

its also entirely possible the heads and or block were milled to make them flat during a rebuild. I don't think the rockers are adjustable on a stock 460, just torque to spec, you should verify this or convert it to adjustable so you can set zero lash.
in short id verify the valve seal to retainer possible interference, oil flow to that lifter, and look to either verify the geometry is correct or go to an adjustable set before putting another cam in.

Just checked the seal to retainer clearance. There is plenty of space and no coil bind neither. I'm waiting on a scope to measure lifter bore clearance. I'm running out of possibilities of what went wrong. I did read a post on a 460 forum about how a guy said his positive seals did "too good" of a job and the valve guides didn't get enough oil, therefore the valve didn't move. Not sure how i'd test that. All the valves are moving fine unless it only happens after engine has reached operating temp.