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Drilling rear cam bearing
https://slantsix.org/forum/viewtopic.php?t=53194		 Page 1 of 3
Author:  duval67 [ Fri Aug 30, 2013 5:45 pm ]
Post subject:  Drilling rear cam bearing
Hey guys.
I have been having an issue with no oil getting to the head of my engine and have now removed the cam and have found that I cannot insert a probe past the cam bearing. So it must have been incorrectly installed or it spun somehow. My question is, is it okay to just drill down through the block and right through the cam bearing rather than pulling the engine to replace the bearing?
Thanks
Author:  Rick Covalt [ Fri Aug 30, 2013 6:26 pm ]
Post subject: 
If it was installed wrong, maybe you could drill it. But if it spun it may just spin again. Did you recently have them installed? Other than that I don't know how you tell if it spun or if it was installed wrong?
Author:  duval67 [ Fri Aug 30, 2013 6:34 pm ]
Post subject: 
I have no idea what was done to this engine before I got it. I bought it as a replacement for mine which had a cracked block. Could have been wrongly installed but the engine was filled with diesel when I got it, assuming it was seized and maybe spun the bearing when they freed it up?
Author:  ValiantBoyWonder [ Fri Aug 30, 2013 8:03 pm ]
Post subject: 
i've had a machinist (not a very good one) install the cam bearing improperly, the result? valves and cam were toast and oil pressure showed 4psi at idle, i'm surprised i didn't spin a rod.

as for drilling it? i'd wait for a more experience engine builder like doc, reed or any of the other veterans to give you some direction on that one.
Author:  duval67 [ Fri Aug 30, 2013 8:10 pm ]
Post subject: 
No kidding. Frustrating to have someone install it wrong like that.
Yeah, I was hoping one of those gents would pop in here before I start working on it tomorrow. My only concern is that I'm not sure that the oil passage is a straight shot through the bearing. If its not, and the bearing is covering the hole in the block, I wouldn't be able to drill through that spot from the block deck.
Author:  Joshie225 [ Fri Aug 30, 2013 8:18 pm ]
Post subject: 
There are two holes in the cam bearing and they are not in line with each other. You could drill the top hole in the right place, but if the bottom hole isn't lined up you're still in trouble. I would pull the engine. Remove the camshaft, knock the cam plug out and see what is really happening
Author:  duval67 [ Fri Aug 30, 2013 8:24 pm ]
Post subject: 
They couldn't have just made it easy for me eh. It'll be pretty hard to tell if that bottom hole is lined up without pulling the engine...I guess I could pull the pan, jack the engine up, pull the crank and then I could tell, but then there isn't much point in not just pulling the engine out.
Actually, where does the bottom hole feed from?
Author:  Reed [ Fri Aug 30, 2013 8:50 pm ]
Post subject: 
Quote:
They couldn't have just made it easy for me eh. It'll be pretty hard to tell if that bottom hole is lined up without pulling the engine
Actually, they did. Josh answered your question.
Quote:
There are two holes in the cam bearing and they are not in line with each other. You could drill the top hole in the right place, but if the bottom hole isn't lined up you're still in trouble. I would pull the engine. Remove the camshaft, knock the cam plug out and see what is really happening
His solution is the only way you will know that the holes are lined up properly. You already know that if one hole isn't lined up then the other hole isn't either. Time to pull the engine.

In another thread of yours I posted the oil feed diagram for the hydraulic slant six.
Author:  duval67 [ Fri Aug 30, 2013 8:53 pm ]
Post subject: 
By they I mean Chrysler, mopar. Not you guys. You guys make it a ton easier.
And yeah I remember the picture you posted. I guess if the bearing was installed wrong, one hole could be lined up and the other not, but I figure its more likely that it spun.
Author:  Doctor Dodge [ Sat Aug 31, 2013 9:24 am ]
Post subject: 
As already noted, trying to re-drill the cam bearing, with-out engine removal, is not a good idea.
If you want to try a "fix" with the engine in the car, drill a hole onto the lower rear head bolt hole, install a fitting & feed oil into that.
DD

Image
Author:  Reed [ Sat Aug 31, 2013 10:00 am ]
Post subject: 
Doc- wouldn't the new hole have to be drilled all the way through both sides of that hole for the rearmost outboard head bolt and into the oil feed passage in the rearmost rocker arm shaft pedestal? I don't see how feeding oil only into that head bolt chamber would provide oil to the rocker arms and also to the pushrod tubes on a hydraulic lifter motor.
Author:  USAJon [ Sat Aug 31, 2013 11:16 am ]
Post subject: 
drill the hole
run it 4short time
no oil
follow what josh said.
Author:  duval67 [ Sat Aug 31, 2013 11:28 am ]
Post subject: 
I have the engine out and all bearings removed. Thanks for the help guys.
The rear had spun and the middle two had big gouges of material missing from them. Any tips for installation without a proper tool? I know I should be using one but its the weekend and I don't have one.
Author:  Joshie225 [ Sat Aug 31, 2013 12:19 pm ]
Post subject: 
You really do need a cam bearing tool in order to knock out and install cam bearings. Call around and see if you can rent one. Probably a bad weekend for this, but you never know. If you can get the engine to a machine shop they can do the job.
Author:  ceej [ Sat Aug 31, 2013 1:05 pm ]
Post subject: 
My machine shop is open Saturday and Monday this weekend. They know lots of people will be working on cars. :wink:

Give a call around, somebody may be open. I never install cam bearings myself. Just buy them at the shop I'm going to use, and they install them for cheap or free. :D

Since the engine is out, you might as well measure everything. This would be the ideal time.

CJ
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