• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Cam bearing oil hole

TopBanana72

Well-Known Member
Local time
1:22 AM
Joined
Apr 3, 2018
Messages
295
Reaction score
243
Location
Ohio
Got my 318 back from the machine shop where they installed new cam bearings. I noticed the center oil hole looks not lined up. Do you think it will be OK?

thumbnail_IMG_1206.jpg
 
Yes I think it will be.
My 383 was similar and has run that way for 24 years.
 
Which cam journal? #2 and #4 need the hole to the rocker arms aligned along with the feed from the mains.
The pictured bearing installation is pretty poor. I would have the machine shop re-install it. If you look, besides the holes not being aligned that well, the bearing was not installed to the same depth of the hole.
It will work as-is as long as the rocker arm feed holes are not blocked, but I expect better quality from the machine shop I use.

Sorry to rant on about quality, but why pay for a service if it is done half-assed.
 
That would just bother me forever knowing for minimal effort it could be right.
The next conversation would be "should you reuse a new cam bearing once it is driven back out".
 
Which cam journal? #2 and #4 need the hole to the rocker arms aligned along with the feed from the mains.
The pictured bearing installation is pretty poor. I would have the machine shop re-install it. If you look, besides the holes not being aligned that well, the bearing was not installed to the same depth of the hole.
It will work as-is as long as the rocker arm feed holes are not blocked, but I expect better quality from the machine shop I use.

Sorry to rant on about quality, but why pay for a service if it is done half-assed.

It's number 3
 
Have them take it out and install a new bearing even if you have to buy a whole set. The shoddy install job blocks the oil supply by over half. Not ok in my book.
 
Have them take it out and install a new bearing even if you have to buy a whole set. The shoddy install job blocks the oil supply by over half. Not ok in my book.
It’s definitely shoddy work and it’s definitely restricting some oil, but there’s so much oil being fed to the cam bearings it’s in no way detrimental to the engine. If in doubt, pull a cam out and put a drill on the oil pump and watch it go!
 
It’s definitely shoddy work and it’s definitely restricting some oil, but there’s so much oil being fed to the cam bearings it’s in no way detrimental to the engine. If in doubt, pull a cam out and put a drill on the oil pump and watch it go!
I'm building the engine, so I'll watch for that when I prime the oil pump...
 
If Chrysler wanted them to be installed that way, the factory would have done it. Chrysler also didnt misalign main cap bearing oil feeds because "it should be ok."
The scary part is the machinist/builder looked at his work, didnt correct it, and just proceeded like a normal day at the shop.
 
I bought the cam bearing install tool about 20 years ago and started doing my own remove/install. If there is a problem, I can only blame myself.
 
I had hand putting the first few sets in , after that it just takes patience and a good tool and make sure they are in the order and direction and life is good!
 
I bought the cam bearing install tool about 20 years ago and started doing my own remove/install. If there is a problem, I can only blame myself.
And the pic the OP showed is why I spend alot of money on specialty tools so I can be sure its done right... Just can't trust people anymore....
 
If the block is grooved the oil will find the hole, that being said oil holes in grooved blocks should be installed with the cam bearing oil hole down towards the pan. The reason is valve spring pressure pushes the cam down creating more clearance on the top of the cam. If the oil hole is up it will have more clearance and drop oil pressure. Might seem insignificant but it will make a difference in oil pressure.
 
If the block is grooved the oil will find the hole, that being said oil holes in grooved blocks should be installed with the cam bearing oil hole down towards the pan. The reason is valve spring pressure pushes the cam down creating more clearance on the top of the cam. If the oil hole is up it will have more clearance and drop oil pressure. Might seem insignificant but it will make a difference in oil pressure.
I don't remember ever seeing a grooved cam bearing bore.
 
I don't remember ever seeing a grooved cam bearing bore.

Sounds like a GM thing? I'm not sure putting the cam hole down to the mains would work on a Big Block Mopar? I think that may block off one of the feeds to the heads, but I haven't ever tried it.

I also haven't seen a grooved cam bearing bore in the Mopars?

I have seen a few other oiling mods, and installing the cam bearing to block the feed holes to the heads is done when the block has the feed holes cross-drilled into the main oil gallery and then oil restrictors are used? This mod allows the #4 main feed to only have to supply the crank and cam, and not the rockers too because the rockers are getting restricted oil feed directly from the main oil galley.

In small block Mopars, having the #2 and #4 cam journals grooved is not that uncommon.
 
Common issue. Just open up the hole with a long drill bit or even small file and a few minutes of work. Zero reason to remove the bearing.
 
It’s definitely shoddy work and it’s definitely restricting some oil, but there’s so much oil being fed to the cam bearings it’s in no way detrimental to the engine.

I agree.

Well...... sort of.
Those holes not lining up is not really going to be where the “restriction” is.
The restriction is the clearance between the cam and the bearing....... which will be way less area than the size of that hole.
 
Auto Transport Service
Back
Top