One of my 70 455 valve covers is much heavier than the other so I think I have PCV gunk packed in the baffle. How can you clean this out?

 

The valve cover w/ the baffle is (obviously) expected to weigh more. I used EZ Off oven cleaner but any oven cleaner will work just fine. You can also use GUNK engine cleaner. Any of those products does an admirable job of cleaning the baffle. Put the valve cover into a pan (of some type). Liberally spray the baffle and apply numerous applications of whichever product you choose. It took me a couple days to be satisfied I'd removed all the built-up debris. Do a final rinse w/ brake cleaner or similar, then a final water rinse. Use an air compressor wand to blow out any remaining gunk. Images are from my 350 intake manifold valve covers before &/or after painting.

 

Maybe they both had a baffle - heck, I can't remember, they may have each had a screen in them - which I don't recall, as well. None-the-less, that's how I cleaned the baffle.

 

There can be a LOT of junk hidden in there and it can take a LOT of time and flushing to get it out. I've had some that were so gunked that they never really cleaned up and kept spitting out small pieces of trash even after an hour of trying to clean them.
The good news is that it doesn't matter very much as long as the gunk isn't loose and falling out and there's a clear path for air to flow. If you stick a borescope in there and see staining and whatnot then that's fine - it's almost impossible to really clean without putting them in a furnace. But chunks of burnt oil are bad news.

 

Yes both of mine have the baffles. I will try some EZoff

 

Try running or sticking some wire or straightened out coat hanger rod up in there FIRST. It really helps if you can sort of "loosen up" any caked on stuff before you go to EZOff, etc. The chemicals will not magically lift the built up crud off the metal in pieces....it's more of slow melting-it-away-from-the-top-layer type deal.

I'm going through the exact same thing right now on a pair of used notched covers.

Cool temps will slow down the process drastically as well once it comes to chemicals and solvents.

Too bad the good caustic liquid hot tanks are pretty much non-existent at machine shops these days.

 

I always wondered if you could put them in an oven outside and bake it out of there? I am sure it would be a crazy amount of smoke.

 

Paul - It took me several days of letting them soak all day, reapplying more EZ Off, etc. etc. Patience it'll work.

 

If originality isn't critical, aftermarket chromed valve covers are under sixty dollars.

 

I have access to a large ultrasonic hot tank parts cleaner with an aggressive degreasing detergent/water at my work. I’ve been impressed with its capabilities literally melting petroleum based deposits as well as loosening any acrylic based paint. Perhaps if you have a local machine shop that has a similar capability, they could make short work of it. Might be worth a phone call.

 

10-4 thanks much.
Looks like the EZ off soak did the trick. A ton of crap came out

 

Once you get out as much as you can to your satisfaction, do a thorough rinse w/ water & air blow (compressor) dry. Active ingredient in oven cleaners is most often NaOH (Sodium Hydroxide) some may use KOH (Potassium Hydroxide) or another similar strong alkali (basically a Lye solution). A thorough H2O rinse ensures alkali residues don't remain.

 

Dont know where you are located but see if there is a local Automotive Machine shop who has a large Ultrasonic cleaner. They work good at that type of stuff.

 

Find a cheap countertop toaster oven, they work great although sometimes aren't big enough for whatever your project is. I keep one out in the shop