Cam bearing issu

C Body Bob

Old Man with a Hat
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Oh the saga of FURYIOUS continues. So last week I’m finally at a point where I can start to carefully assemble the 440 short block. Checking & cleaning as I go. I noticed while cleaning that two of the cam bearings were about half way covering the oiling hole in the block & another about 1/3rd. Also they weren’t pressed in all the way. Clearly a sloppy job. So I took the block back & had the guy look at it. He owned up to & with the block sitting on the tailgate of my truck he got his bearing installer & pressed out the three & reinstalled them. Two are still not dead nuts lined up but close enough. Just a smidge off. Personally I would have made certain they were dead on with the customer right there watching , but he’s supper busy shop & had people lined up wanting to drop stuff off. I was watching how he did it & I can see how he made the mistake. He’s not very careful. Anyway my concern now is that since 3 where pressed out then back again are these bearings ok ? I guess so. He said so but now my confidence is of his work is diminished. If one of those bearings siezes to the cam & spins it will ruin the block. Also the heads he did for me I put a straight edge across the valve stem tops & three are low on one head & 2 on the other. I feel like he should have caught that & recomend have them cut. I guess I can run a lash cap on those 5. I wanted to run stock rockers but I’ll probably have to run adjustable now to dial in the correct lift on all 16 valves. You really have to double check these machine shops. I don’t know if I should get someone else to press in new bearings or let it go. I can carefully rotate the cam & feel for tightness but I can’t simulate the heat cycle. Your thoughts on this. I’m just not sure. I think he needs to slow down, take in less work & charge a bit more & make certain everything that leaves his shop is dead on.

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How low is low on the valve tip differences. The stock stamped rockers in good shape will preload like .050-.080 so a .040 gap is not the end of the world. Cam bearings suck, that's why I never touch them unless I have to. That's a judgement call on your part. I'll bet with the in, out. in, that the cam is tight in there. I hate scraping those cam bearings to clearance the high/tight spots.
#4 is the main concern with hitting all 3 holes that seems to never happen, always a compromise. If you have at least half the hole open I would not sweat it. That's more than enough on a non reciprocating bearing IMO. It's only going to spin to 3k maybe 3500 and cam is pushed down on holes limiting amount flowing onto the journal.
 
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Oh the saga of FURYIOUS continues. So last week I’m finally at a point where I can start to carefully assemble the 440 short block. Checking & cleaning as I go. I noticed while cleaning that two of the cam bearings were about half way covering the oiling hole in the block & another about 1/3rd. Also they weren’t pressed in all the way. Clearly a sloppy job. So I took the block back & had the guy look at it. He owned up to & with the block sitting on the tailgate of my truck he got his bearing installer & pressed out the three & reinstalled them. Two are still not dead nuts lined up but close enough. Just a smidge off. Personally I would have made certain they were dead on with the customer right there watching , but he’s supper busy shop & had people lined up wanting to drop stuff off. I was watching how he did it & I can see how he made the mistake. He’s not very careful. Anyway my concern now is that since 3 where pressed out then back again are these bearings ok ? I guess so. He said so but now my confidence is of his work is diminished. If one of those bearings siezes to the cam & spins it will ruin the block. Also the heads he did for me I put a straight edge across the valve stem tops & three are low on one head & 2 on the other. I feel like he should have caught that & recomend have them cut. I guess I can run a lash cap on those 5. I wanted to run stock rockers but I’ll probably have to run adjustable now to dial in the correct lift on all 16 valves. You really have to double check these machine shops. I don’t know if I should get someone else to press in new bearings or let it go. I can carefully rotate the cam & feel for tightness but I can’t simulate the heat cycle. Your thoughts on this. I’m just not sure. I think he needs to slow down, take in less work & charge a bit more & make certain everything that leaves his shop is dead on.

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Maybe I missed it somewhere Bob, but why not do it yourself and make sure it gets done right? A used cam bearing tool can't be that pricey. I know what you're saying about this guy's shop, but if he's okay with shotty craftsmanship with your money - I'd look elsewhere.
 
Sounds like his shop is TOO busy to do quality work. I would never reinstall a cam bearing. But, maybe I'm just fussy.
 
Maybe I missed it somewhere Bob, but why not do it yourself and make sure it gets done right? A used cam bearing tool can't be that pricey. I know what you're saying about this guy's shop, but if he's okay with shotty craftsmanship with your money - I'd look elsewhere.
Well he did all the other machine work. He’s got a good reputation. Done several engines for buddies. Lots of blocks there being worked on. I think he’s a bit overwhelmed. Trying to please everyone
 
How low is low on the valve tip differences. The stock stamped rockers in good shape will preload like .050-.080 so a .040 gap is not the end of the world. Cam bearings suck, that's why I never touch them unless I have to. That's a judgement call on your part. I'll bet with the in, out. in, that the cam is tight in there. I hate scraping those cam bearings to clearance the high/tight spots.
#4 is the main concern with hitting all 3 holes that seems to never happen, always a compromise. If you have at least half the hole open I would not sweat it. That's more than enough on a non reciprocating bearing IMO. It's only going to spin to 3k maybe 3500 and cam is pushed down on holes limiting amount flowing onto the journal.
Haven’t measured it
 
After the cam bearing rearrangement, did he test-fit a camshaft to check that it turns freely? At my shop, if a bushing has to be removed, it's not getting put back in. They don't go in a second time with the same "press fit".
 
If you want, you should be able to open up the oiling holes. The bearings are very soft and it's very easy to do.
 
After the cam bearing rearrangement, did he test-fit a camshaft to check that it turns freely? At my shop, if a bushing has to be removed, it's not getting put back in. They don't go in a second time with the same "press fit".
No I’ll check it.
 
I'm sure that somewhere, there is a clearance spec for the cam bearings' dimensions and camshaft journal diameters, so you can use an inside-micrometer to check those inner diameters, if you are concerned.

Personally, as long as the cam spins freely in the cam bearings, no real reason to be concerned. IF that is not possible, THEN worry about the deal. You can tell which ones are not "to spec" when sliding the cam into them.

One late Saturday afternoon, I was at my late machine shop operative's shop. He'd done the block for a drag racer customer. The customer showed up saying that the back cam bearing was too tight. It was verified to be that way, so he removed the welch plug on the back of the block and took out his used pocket knife and clearanced the bearing until it fit and the camshaft spun freely. Then he made sure everything was clean and replaced the welch plug. The customer went back to his shop to complete what was left to do.

We all want things done exactly as we've come to expect them to be "correct", but there are some things which can be "fudged" a bit and not cause any issues. Some might term these things "defective", but if they've worked with no issues for a good while, it just proves how much "wiggle room" exists in certain areas.

Personally, I might be more concerned about the valve stem heights. Are the tall ones on seats which have been sunk a bit or is the end worn off of the stem's end on the short ones?

How long had the engine been running before it was torn down and the indiscretions discovered?

Just some thought,
CBODY67
 
I'm sure that somewhere, there is a clearance spec for the cam bearings' dimensions and camshaft journal diameters, so you can use an inside-micrometer to check those inner diameters, if you are concerned.

Personally, as long as the cam spins freely in the cam bearings, no real reason to be concerned. IF that is not possible, THEN worry about the deal. You can tell which ones are not "to spec" when sliding the cam into them.

One late Saturday afternoon, I was at my late machine shop operative's shop. He'd done the block for a drag racer customer. The customer showed up saying that the back cam bearing was too tight. It was verified to be that way, so he removed the welch plug on the back of the block and took out his used pocket knife and clearanced the bearing until it fit and the camshaft spun freely. Then he made sure everything was clean and replaced the welch plug. The customer went back to his shop to complete what was left to do.

We all want things done exactly as we've come to expect them to be "correct", but there are some things which can be "fudged" a bit and not cause any issues. Some might term these things "defective", but if they've worked with no issues for a good while, it just proves how much "wiggle room" exists in certain areas.

Personally, I might be more concerned about the valve stem heights. Are the tall ones on seats which have been sunk a bit or is the end worn off of the stem's end on the short ones?

How long had the engine been running before it was torn down and the indiscretions discovered?

Just some thought,
CBODY67
I can’t answer any of the questions about the heads. I bought them used & they look to have been run for a year or so. I paid the shop to go through them. Him & I discussed the stem height & I thought we had agreed to address that but for some reason it wasn’t. So I guess I will. I haven’t measured anything as I don’t own those tools. I just put a straight edge across & visually saw several were off. I’m covered up with customer work right now so I don’t know when I can get back to this engine. I had sat aside this past weekend to assemble the short block & that didn’t happen when I saw the cam bearings.
 
At my shop, if a bushing has to be removed, it's not getting put back in. They don't go in a second time with the same "press fit".

A bushing is a lot different than a bearing! I wouldn't use your shop either if you don't know the difference!

If you want, you should be able to open up the oiling holes. The bearings are very soft and it's very easy to do.

Often done in the /6 world! Good Luck
 
Oh the saga of FURYIOUS continues. So last week I’m finally at a point where I can start to carefully assemble the 440 short block. Checking & cleaning as I go. I noticed while cleaning that two of the cam bearings were about half way covering the oiling hole in the block & another about 1/3rd. Also they weren’t pressed in all the way. Clearly a sloppy job. So I took the block back & had the guy look at it. He owned up to & with the block sitting on the tailgate of my truck he got his bearing installer & pressed out the three & reinstalled them. Two are still not dead nuts lined up but close enough. Just a smidge off. Personally I would have made certain they were dead on with the customer right there watching , but he’s supper busy shop & had people lined up wanting to drop stuff off. I was watching how he did it & I can see how he made the mistake. He’s not very careful. Anyway my concern now is that since 3 where pressed out then back again are these bearings ok ? I guess so. He said so but now my confidence is of his work is diminished. If one of those bearings siezes to the cam & spins it will ruin the block. Also the heads he did for me I put a straight edge across the valve stem tops & three are low on one head & 2 on the other. I feel like he should have caught that & recomend have them cut. I guess I can run a lash cap on those 5. I wanted to run stock rockers but I’ll probably have to run adjustable now to dial in the correct lift on all 16 valves. You really have to double check these machine shops. I don’t know if I should get someone else to press in new bearings or let it go. I can carefully rotate the cam & feel for tightness but I can’t simulate the heat cycle. Your thoughts on this. I’m just not sure. I think he needs to slow down, take in less work & charge a bit more & make certain everything that leaves his shop is dead on.

View attachment 530826
Cam bearings are like condoms. You use them once. The idiot you took your block to needs to have his tools taken away. Were these cam bearings machined to the diameters of the cam journals? Pounding them out of the cambores and then back in isn't going to do anything but **** the bearings up. You do know that the journals aren't all the same size, right? IOW, find a new machine shop that knows what they're doing. Your guy obviously does not.
 
Just checked "69 FSM and found that reccommended procedure is to remove and reinstall cam bearings to fix oil holes "out of register". Not trying to start an argument; "just sayin'". Lindsay
 
bob , replace them with new ones . tell you a story about my buds 383 . he heard a rattle it was in the front under the timing cover . so he pulled it down and found the first cam bearing was lose and out of the hole . it was a newly build motor . so we replaced it , just to hear that same nose a few miles later . we measure everything up . it was the block , holes were miss alined . we ended up pulling full groved bearings and lock tighting them in . reduced the cam mains to the miner side . all just made a street motor out of it . i have seen miss alined cam and crank mains in chrysler blocks .
 
Just checked "69 FSM and found that reccommended procedure is to remove and reinstall cam bearings to fix oil holes "out of register". Not trying to start an argument; "just sayin'". Lindsay
Yea my crew chief says to run them. He’s coached me on how to check them.
 
Two things:

#1 straight edge and feeler gauge, as mentioned. I don't want to bad mouth anyone cuz I'm CERTAINLY no machinist, but if you paid him to rebuild and refurbish your heads then that certainly should have been checked and if not covered in your price you should have been called and asked if you wanted it fixed. Unless you're talking about .005" and maybe he said "close enough". Because it really is close enough at that sort of difference. Are you running hydro or mechanical?

#2 no way should the bearings be installed, removed and installed again. They are press fit for a reason and once they have been removed it is incredibly unlikely that they will be true enough to hold up under high heat and load. I know it's not the same abuse that a crank bearing would see but trusting the soft metal to hold up when weighed against the potential damage is a no brainer.
 
Two things:

#1 straight edge and feeler gauge, as mentioned. I don't want to bad mouth anyone cuz I'm CERTAINLY no machinist, but if you paid him to rebuild and refurbish your heads then that certainly should have been checked and if not covered in your price you should have been called and asked if you wanted it fixed. Unless you're talking about .005" and maybe he said "close enough". Because it really is close enough at that sort of difference. Are you running hydro or mechanical?

#2 no way should the bearings be installed, removed and installed again. They are press fit for a reason and once they have been removed it is incredibly unlikely that they will be true enough to hold up under high heat and load. I know it's not the same abuse that a crank bearing would see but trusting the soft metal to hold up when weighed against the potential damage is a no brainer.
Hydraulic cam. 509 purple shaft. We’ve decided to replace the bearings
 
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