Hi Everyone,

Thought I'd reach out to the experts on here and see what everyone might think.

I'm having an oil pressure issue with a 68 Charger with a 383. I've had a bunch of issues with the engine in the past few months which I've been sorting out, but it has now gotten me scratching my head to figure out the next steps.

After installing a new camshaft (used the original cam bearings, they were still good), new hydraulic flat lifters and new push rods. I had an issue with getting oil pressure to the left side head only. Had good oil pressure on the right side. Checked the oil ports to the head and both were clear, used a wire and made it all the way through the bearing. The bearing has not spun. I've been spinning the oil pump (new) with a drill to watch oil flow and it appears to be flowing around the engine good. As a test I used a small amount of compressed air on the head ports, again both were clear.

Removed the rocker shafts on both sides, have good oil pressure on the right, nothing on the left. Also upon removing the left side push rods, the engine seems to have developed better oil pressure around the lifters on the left side which it wasn't getting before.

I've changed the oil pump, changed the oil and filter, new distributor drive gear and bushing, new timing chain, camshaft, lifters and rods. The rest of the engine is original. Assembly lube was used upon installing all new parts.

After running the engine for a few minutes, I was hearing an internal engine squeal develop. Checked oil pressure, its good. Upon continuing diagnosis, I've had to rip the engine back apart again and found the camshaft bearings are now destroyed.

After all this I'm not sure what direction to head. Is there something I'm missing or forgetting? I'm not all that familiar with these engines.

Thanks for the help!

G.J.

 

Welcome.

#1- While priming the engine manually did you turn the engine over by hand to line up the cam oil feed holes? These are designed to work as a restriction and as it turns while running "squirts" a little to the right side then a little to the left side.

#2- The push rod deal, don't know, unless the lifters came up and exposed the oil galley, doesn't make too much sense to me.

#3- Did you turn only the new camshaft before installing chain to "feel" how free it was? I ask because they have been known to have large core shift and a new cam with maybe a little to big journal or even not straight from shipping can be too tight and damage bearings.

Important to diagnose - what cam bearings were damaged? Number 4 feeds oil up to the heads.

A quick oil path synopsis: from the pump to #1 main crank and up to passenger side oil galleys (not much needed for lifters) goes to the back and across to driver side lifters.

Critical part is from the passenger side it goes down to the other main bearings AND back up to the cam bearings.

If you search Mopar big block oil diagram or schematic, I'm sure you'll find one and see what I'm trying to describe.

 

Is it possible? You have an engine with factory oversize lifter bores? Look in the shop manual, I believe you look for the diamond stamping on the engine pad is .008 OS, and the manual says .005 OS is the letters "OS" on "single bolt stamping on end of head." Don't ask me what that means I've never seen that.

Now, not all bores might be OS. I have a 340 block with 2 of them.

 

what DDodger said is what my 1967 charger factory manual says. a diamond = .008 O/S Tappets "A" is .020 O/S cylinder bore. i saw a 1970 440 with .010 over cylinders. i measured it 4 times. and you can NOT get them from the factory. in our MOPAR club we have a saying about chrysler " never say never" .

 

My 2 cents.....

Sounds like a Alignment issue or one of the cam bearings was damaged when reinstalling the new cam...

This should have been a straight forward swap with out and issues...

BOb

 

A block with warranty work done. If there was a problem they would fix one or two holes and not do a complete overhaul.