Engine Cleaning

When I got my engine, it was packed with thick, solid grease and other gunk. The suggestion to power wash your engine before taking it home is a good one. $10 in quarters made a big difference.

Bead blasting

The recommendation by WilliamWynne and others is to avoid bead blasting or blasting with other media of your engine to prevent surfaces that must be kept perfect from being damaged. Chemical cleaning and elbow grease is the recommeded route. Blasting can introduce bits into oil channels. The heads can be damaged by blasting and there are other surfaces of the head that need a near-perfect finish.

• The seats where the rocker studs go have an O-ring seal that needs to be tight and clean.
• The PushRodTubes have O-rings where they enter their holes in the head.
• The SparkplugPockets need to be bright and smooth for the plugs to seal properly.
• The ValveCovers have a thick gasket, but the head surface needs to be clean and true if leaks are to be avoided around the valve covers.

Some people have blasted with walnut shells or plastic granules with success. Another media to blast a case or heads is sodium bicarbonate. It's available at places that sell animal feed. It's not fast and it can only be used once as it powders upon use, but it produces nice results. Afterwards, a good soak in water and it will dissolve and fizz away without leaving contaminates behind.

Liquid Plumber

Paint it on full strength and let it sit for several minutes. Use soap and water to clean off a film residue when finished.

• It does a great job on cleaning aluminum parts without nasty fumes.
• It is fairly safe. Low odor and doesn't burn if you get it on your hands (use gloves).
• It is water soluble, rinses off easily and is certainly safe for your drains.
• It is cheap and available in most grocery stores.
• A quart goes a long way.

Notes and postings on cleaning by List Serve members

This by John Pitkin:

I have discovered Liquid Plumber is very good for removing caked grease and oil stains. It's cheap, fairly safe, and has a low odor. Cleanup is with water. I found it far less "nasty" than carburetor cleaners and just about as effective. It works well on both steel and aluminum. For small parts, I drop them in a plastic dish (bottom of a milk jug) and cover with the liquid. The plumber won't eat plastic like some solvent cleaners.

By the way, parts cleaning in the dishwasher works very well for that final scrub. It is best done when the spouse is not home. There will be no evidence when the job is done as the parts and the dishwasher get cleaned at the same time, but some spousal units get upset seeing a cylinder head in the dishwasher. You've been warned.

This by Marty Smiltneek:

I have used mag wheel cleaner with cold water a number of times. You will be surprised at the results after three or four times.

This by Rad Davis:

The key, as others have said, is to use non-erosive media. Since the aluminum in a Corvair head is very soft and thorougly annealed by the hundreds of drive cycles it's seen, you need pretty soft media and probably less pressure than you're used to.

The good news is that you're talking about removing varnish and crud, not paint or rust--the job's a lot easier than rust removal.

You should have good luck with styrene or walnut shells. Even glass beads should be OK if used gently. No matter what you use, if you want to clean the combustion chambers off, you should probably mask the sealing faces with old head gaskets. I hit two spots
on either side of the sealing face with silicone sealer, then just plop a gasket down in it. The gasket protects the sealing surface. You may have to wash that part of the sealing face and gasket with brake cleaner to get the oil off before the silicone will stick.

After blasting you should be extremely thorough with soapy water and a scrub brush to get the particles of crud and blast media off the valve guides, in particular. Rifle bore brushes are handy here. Dry the head in a 300 F oven after washing. This boils all the water off before it can cause corrosion. You may have to bag your heads with a light oil soaked rag to keep them corrosion free after washing if you live somewhere humid.

I'm much more cautious about using any kind of media blasting on cranks and cases. Too many little passages that must all be cleaned afterward. Little particles of blast media or loose crud somewhere bad in the oil galleries can ruin your whole day.

Likewise, I've never had the urge to either blast or wash pushrods. Yes, my pushrods probably have some carbon inside them. As long as oil comes out the two spit holes, it can stay there. I just don't want to risk getting a chunk of carbon (or worse, blast media) loose inside the rod where in can plug up the radial spit hole.

Oil coolers are another area deserving caution. It's easy to clean the outside. It's very, very hard to clean the inside well enough that you know there's not a blob of wannabe-diamond in there just loose enough that it's going to make it into your main bearings.

Cleaning bolts

This by Tom Cummings:

I cleaned some bolts by drilling holes in a 2x6 board and then thread the bolts in tight. This provided a holding fixture to either wire wheel them or sandblast them. Nuts and bolts in a wire basket with a wire mesh lid provides a method to capture small items for blasting. Shake, rattle, and blast! I bought several special brushes from Torrington Brushes. Pencil brushes were very helpful in scrubbing nook and crannies. They have all kinds of brushes in a variety of shapes and sizes.

Other notes:

Note - some of these methods need the appropriate respirator and do this in a well-ventilated area with thick rubber gloves, long enough to protect the arms.

• Oven cleaner has been used. Spray on and rinse off with water. However, leaving it on too long will cause it to corrode the aluminium.
• A bucket of carb cleaner can be used.
• Harbor Freight sells some kind of purple degreaser
• 3M adhesive remover, usually available at auto paint stores
• Acetone
• A wire wheel can be used on bolts and larger steel fasteners after washing in solvent to remove soft grease.
• Mineral Spirits - rocker arms can be soaked in this
• Harwood scrapers are hard enough to remove crusty old gaskets, but soft enough not to damage aluminium or steel.
• Gaskets can be cleaned off with Permatex Gasket Remover. It can be obtained at auto parts stores and is in a blue can. Spray it on, come back in 10 minutes, and the gasket is all bubbled up waiting to be wiped off. Stubborn places may require another
  spraying.

-- NormanSmit - 13 Jun 2010