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440 cam eating bearings

S

Southern welder

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Hey yall,
I have the misfortune of having a 440 problem child, my latest escapade is while attempting to rebuild it I found the camshaft is tight to turn, you have to put a wrench on it to turn. So I spun it a few times and the cam was eating the bearings, took to a useless machine shop, then supposedly installed 2 sets of bearings and both were tight, he said he spent 2 hours on it, crazy.

So anyone have any ideas? The new set of bearings are also being eaten by the cam (spin the cam 6 times the oil is sparkly) I thought about sending the cam back to comp cams and letting someone actually check it, could it be a block issue? Too tight of bearing holes or offset hole? By the way then cam spins easy about 1/2 way and then gets tight the other half, which is why I thought the cam might be bent the first time.
Thanks
 
Take cam bearings out, wash block, dress the cam bearing bores where the oil holes are drilled, and dress down any gouge marks. Mopars are known to be the worst for fitting cam bearings. Carefully install cam bearings, and install cam with assembly lube. If it is tight, turn it a 1/4 turn, remove the cam, and then scrape the high spots with a bearing scraper. The high spots will show up as darker spots on the bearing. They will usually show up where the oil hole to the mains are drilled which I previously said to dress down those spots.
 
The cam is easy to check.
Just measure the journals with a mic.
They’re either in spec or they’re not.
Cams often get bent in transit...... so check it for straight as well.

But, as mentioned above..... the BB Mopar cam housing bores are pretty often not the correct size, and/or not in great alignment with each other.

They can require quite a bit of time invested to get them corrected, which can include needing some work done to the housing bores.
 
Not uncommon. Can you tell which of the cam bearings are tight? It usually leaves obvious marks on the bearing. Trimming the bearing will often work.
Edit: Do see if you can check the cam straightness.
 
We recently installed a lunati voodoo, all the journals were very slightly oversized, it was not off much... probably the top end of spec when we measured it. It does not take much for it to be tight. I put the cam in the lathe and polished it down to spec. The same engine we had to reinstall the back cam bearing twice. It somehow got a burr, even though we have a nice cam bearing installation tool, it does happen.
 
Southern welder said:
Hey yall,
took to a useless machine shop, then supposedly installed 2 sets of bearings and both were tight, he said he spent 2 hours on it, crazy.
Click to expand...

This was your first problem that you have a problem, but that's not my problem!
I'd talk to Comp about it but I'm sure you won't get much help out of them. Good Luck
 
Ol' trick I heard for this issue is to take an old cam and cut slots on a 45 angle into the cam journals, creating a reamer of sorts. Never tried it myself but may help.
 
I had a short block built by Chenoweth in Ill. 15 years ago, he had a cam with slots cut in it that he used for final sizing of cam bearings. Engine still in action 15 years later.
 
This kind of crap is why i will never, ever, change cam bearings in a big block mopar again.
And i wont clean a block in any way that requires cam bearing removal to avoid destruction.
 
33 IMP said:
This kind of crap is why i will never, ever, change cam bearings in a big block mopar again.
And i wont clean a block in any way that requires cam bearing removal to avoid destruction.
Click to expand...
That's just silly. Blocks are 40-50 years old and they're gonna need cam bearings at some point. Just need attention and work like everything else we do. There's no "Drop in" parts.
 
Just cut some grooves with a cut-off wheel in a dead 440 Cam blanks journals..... then winde the cam blank into the just installed Bearings to remove the high spots.... finish by polishing the then corrected bearings with a piece of scotch brite pad on a piece of redi-rod with a drill and solvent.

If nobody posts up a Pic ?
Then I'll take one later and post it.... until then
 
68Dart470 said:
That's just silly. Blocks are 40-50 years old and they're gonna need cam bearings at some point. Just need attention and work like everything else we do. There's no "Drop in" parts.
Click to expand...
I have changed cam bearings in engines that were perfectly good, simply because the block was gonna be hot tanked. Im just not gonna do it anymore.
And, i have never owned a 400/426w/440 that NEEDED cam bearings.
 
Challenger340 said:
Just cut some grooves with a cut-off wheel in a dead 440 Cam blanks journals..... then winde the cam blank into the just installed Bearings to remove the high spots.... finish by polishing the then corrected bearings with a piece of scotch brite pad on a piece of redi-rod with a drill and solvent.

If nobody posts up a Pic ?
Then I'll take one later and post it.... until then
Click to expand...
You were doing fine until you got to the "Scotch-Brite" part. Cam bearings are "Babbit" and can NOT be scotch-brited or sanded. You WILL embed particles and ball up babbit and destroy the bearings. Babbit can only be cut or scraped with a knife to fit.
 
33 IMP said:
I have changed cam bearings in engines that were perfectly good, simply because the block was gonna be hot tanked. Im just not gonna do it anymore.
And, i have never owned a 400/426w/440 that NEEDED cam bearings.
Click to expand...
Most shops today use a jet wash, and the cleaning solution is usually safe for aluminum and bearings. I am sure there are shops that still "hot tank" with a caustic solution, or "jet wash" with an aluminum safe solution that is too strong, but I would say that most shops today use a solution that is safe for your bearings. All you need to do is ask the shop what they have and solution used. I would also disagree with the last statement unless they were already replaced.
 
Challenger340 said:
Just cut some grooves with a cut-off wheel in a dead 440 Cam blanks journals..... then winde the cam blank into the just installed Bearings to remove the high spots.... finish by polishing the then corrected bearings with a piece of scotch brite pad on a piece of redi-rod with a drill and solvent.

If nobody posts up a Pic ?
Then I'll take one later and post it.... until then
Click to expand...
Yep if I can't get it happy with the bearing knife, the ol' cutter cam is the next step..
20200429_141940.jpg
 
Had RPM Racing Engines do my block work and install the cam bearings using the cam I'm intending to use so they are correct. Had them buy the right mains and rods too.
 
Do not start scraping bearings until you measure the camshaft for size and straightness.
I had the same thing happen, also on a brand new Competition Cams part, a solid flat tappet cam. I had the old camshaft and another replacement on hand to try and they slipped right in. Measured camshaft and found all bearing journals were over spec. Bearings were all perfectly in spec and round. I forget the actual measurements.
Comp Cams tech told me their QC documents don’t show they sent it out the doors over spec. No ****!
I had to pay shipping to send it back to them. They did fix it and then said they don’t do any of these flat tappet grinds in house, they arrive finished from their supplier. Not sure if it’s true or not but I won’t buy another Comp Cams flat tappet camshaft based on this whole episode. He said they do the billet roller camshafts in house.
As a side note, my solid flat tappet was ordered from them with their nitride treatment. It initially looked like the whole camshaft was nitrided and the bearing journals were not reground to completely clean them off. To correct it, they just ground or polished the journals back into spec and I measured it to verify that when it returned.
 
An interesting story. Never seen a new cam that had the nitriding(or whatever coating) left on the bearing journals. Coating thickness an obvious issue. Comp Cams QC problems!
 
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