This is on a bone stock 5.9 Magnum motor I picked up to replace the tired one in my 2000 Dakota. My intentions was to run it "as is" with a valve job on my heads. I haven't seen quite an "distinctive" wear on the cam before. Maybe it's the dark oil that makes it stick out? Obviously, the previous owner didn't change the oil at intervals. Thoughts? I really don't want to tear in the motor.

Unless you can see something in person that is not showing up in the pic then run it. That is how they all look. If you can not feel any wear on it and it is just the line in the middle that is how they look. I have seen pits on the top of the lobe but there is usually a wide wear pattern to match. Also there is not much sludge in there, usually the worn ones have a bunch of sludge.

Thanks Dave. I can't feel anything on the lobe.

Now, if I could find one of the old "R/T +10" cams, I would switch to that!

it is just lack of oil change and a lot of miles run on it. Like Dave said, if you can't feel any wear on it just run it.

Thanks guys!

Yeah, that brown stuff is varnish. It's a very interesting subject in its own right.

R.

Varnish has only recently been studied with any level of intensity. This was caused IMHO by the change from Type I base stock to Type II base stock. The Type II oils are more refined and they contain far fewer solvent-type molecules. As a result, Type II oils have more tendency to leave varnish deposits.

What is varnish? It seems to be extremely fine particles of oxidation products. These oxidation products are formed when something acts as a catalyst to the oxidation reaction. Often times it is water that catalyzes the reaction.

Varnish can be filtered out of oil with special varnish collecting filters, or removed by electrostatic filters. Varnish becomes more soluble at higher temperatures, so varnish will collect faster in the cooler spots of the engine.
New batches of hydraulic oils that come from the suppliers tend to be Type II oils. As these replace the Type I oils, we have noticed varnish problems, specifically in hydraulic systems where the valves will stick.
A short term solution is carb cleaner, which I used to de-varnish the inside of a block I was rebuilding. This block was from my personal car and had had regular oil changes, yet was covered with varnish.

I don't know exactly how to deal with varnish in an engine, most of my work involves either huge journal bearings or hydraulic systems. In those we can use a "kidney loop" filter system with special varnish-collecting media.

R.

Good information! I am not sure the harm of this varnish in the engine (aside cosmetics) so would you suggest I even try to address it? I don't want to pull the motor apart.

From what I read in dogdays post is blast it with carb cleaner where u can, wipe/rinse it down and rock on

I would not disturb any of it. If it is stuck down it is not going anywhere, if you mess with it than it will come loose and go through the oil system. That engine looks real good, low miles and typical of a magnum with reasonable maintanence.

Thanks. Im going to get my RHS heads a valve job, put them and my M1 on it and let her go. Oh, and get the Powerdyne rebuilt with the CNC impeller!

Where the varnish can hurt is where you have close sliding tolerances. In an engine that could be for example the lifter bores or the oil pump pressure relief valve. I'm not sure it's a problem that demands immediate action.

R.