I took the valve cover off to 'polish' the outside, and I noticed that the inside had a coating of oil 'varnish.' Would there be an advantage to removing the varnish? What is the usual way to do that? (FYI)

thx.

In my garage it is done with Solvent, a Wire Brush, and Elbow Grease. Is there an advantage? Well, I can look at it without going "Eeek, that looks like $hit". Good enough for me.

It probably could also be done by dipping in an (Aluminum safe) Hot Tank, but I'm too cheap to go that route.

I reckon there is nothing better than plain metal nicely polished up. Hit it with Wet and Dry, brush and then sand her down. Hit with some metal polish and bingo - lookin good :cheeky:

biker- Polish the INSIDE??

I just thought there would be an advantage to removing the baked-on oil coating on the inside, but as long as the air can get up into the vent hose, I don't think any varnish will hurt- unless it flakes off and gets into the works.

We used to paint the oil galley and the inside of the engine block ( and the outside of small engines) with an oil-proof enamel that allows the oil to flow back to the oil pan more quickly. On the small (2-cycle) engines, it's used to protect the outside, so the oil can be wiped off easily.

Nobody will see what on the underside of the valve cover anyway.

Last year when I got way too involved in cleaning the valve cover, I used simple green to get the 'greasy' stuff out. After that, I let it sit in my shop sink overnight with ATF and simple green. ATF does wonders for that type of work.

Oops - I thought we were talking about the outside

Can't hurt to polish the inside as well but why would you want to???

Agree with you Tomohawk - just give it a good rub with some solvent such as Acetone or Carby Cleaner to get the oil stain off (It seems to get everything off).

Biker

As I recall, I tried a few different solvents on the inside of mine when I last had it off without any real success. I just left it there. I figure if all that baked on carbon was so firmly attached, it probably wouldn't come off on its own and cause damage to engine parts. (*knock on wood*)

If I was really determined though I would probably end up taking it to a machine shop and have them do some sort of hot tank dip on it since the shape of the underside would make anything else pretty difficult IMO

Yeah, I used laquer thinner and a s/s brush, but the crud took a fair amount of effort to remove.

If you take it to a shop to be dipped, make sure they understand that the Valve Cover is aluminum. Some hot tank solutions will EAT aluminum.

Go to NAPA and get a gallon of Mac's 6401 carburetor cleaner. Wonderfully nasty stuff that probably isn't avaliable in CA Anyway shake it up, pour it in, let it set a while, pour it back in the can and crud is gone! I filter mine back into the can and have been using it to do about everything including removing paint from fittings. Great stuff, but follow the cautions!

I had some MEK on the shelp and tried that, which did work with a little time.

But on the timing chain end, I noticed some scratches that looked like the timing chain was rubbing. Has anybody else noticedthat on their engine? After removing the varnish, I didn't see any noticeable scratches or grooves on the metal itself.

thx

Could be marks from hitting the chain whilst removing/replacing it or something. There seems to be a fair bit of clearance there.

If it just looks like a circular mark from where the timing chain sits underneath it's probably the normal pattern caused by the oil splashing up against it. I wouldn't worry about the timing chain hitting it.