removing carbon from exhaust valves, cleaning aluminum parts.

i've procured the LS6 heads for my impala, and my valve spring compressor came the other day.

I am switching out to new valve springs for my new cam, and have encountered lots of carbon. some exhaust valves have a thick layer on the combustion side, and all have quite a bit on the stem and backside of the valve head.

how do i remove it safely without damaging the machined sealing surface of the valve? is there something readily available that they can be soaked in?

also - is there some solution i can mix up or buy in a bucket to toss big aluminum parts into and degrease/clean them to look relatively new? or at least remove all the nasty crap without pressure washing it all over myself/the driveway/everything within 50 feet. i thought of getting some glass bead for my blasting cabinet because it leaves a much nicer finish on aluminum than sand does. i have 2 large accessory brackets for my truck that look like crap, and i'm trying to make that engine look as nice as possible with cleaning and rattle can black engine paint and as factory correct as possible before i drop it in.

wouldn't mind soaking the aluminum LS6 heads too once disassembled to get them cleaner than i can in the parts washer with brushes and mineral spirits.

Wire wheel for the valves, and one of the purple degreasers for the heads, but read the instructions first.

I've used a wire wheel on the valves with sucess. I don't know about LS engines, but it's probably a good idea to lap the valves with grinding compound before you reassemble the heads.

For cleaning the aluminum parts, NAPA sells what they call aluminum brightener cleaner; it comes in a spray bottle or a gallon jug. It's nasty stuff (wear rubber gloves and eye protection) but it works very well.

Caustic degreasers (like the purple stuff)are incredibly effective but, will at the minimum discolor aluminum and if left too long can start to degrade it.

Acid based cleaners aren't as effective on oils but will really clean the aluminum.

Perhaps the best compromise might be to clean with a diluted caustic and then bring back the finish with a brightener.

the "wash" setting at the local coin operated car wash gets engine parts as clean as they need to be for a driver.. they won't look foundry fresh, but it's an engine, and engines get dirty almost immediately once you start driving down the road.

Baked on oil on internal aluminum castings and heavy grease/dirt will melt away with "aircraft paint stripper". You can get it in the paint section of most auto parts stores.

Just spray it on and power-wash it off. I take my stuff to the coin car wash for power-washing.

It also cleans up the combustion chamber carbon deposits.

For valves, I put a lot of tape on the stems and chuck the valve on to the drill press and use an angle grinder with a wire wheel to get the valves looking brand new.

fujioko wrote: Baked on oil on internal aluminum castings and heavy grease/dirt will melt away with "aircraft paint stripper". You can get it in the paint section of most auto parts stores. Just spray it on and power-wash it off. I take my stuff to the coin car wash for power-washing. It also cleans up the combustion chamber carbon deposits. For valves, I put a lot of tape on the stems and chuck the valve on to the drill press and use an angle grinder with a wire wheel to get the valves looking brand new.

All good stuff. You did mention that you had a blast cabinet. Yes do get some glass beads and clean the valves and aluminum parts if they fit in the cabinet. First de-grease the parts as best as you can. I use glass bead to clean heads, valves, intakes, etc.

As has already been suggested a wire wheel should work fine on the valves. If this is a cheap "dirty" rebuild... a quick lapping will get you nice tight combustion chambers... I would recommend a multi-angle valve job and back cut valves.

After the valves are clean, pop them back in their guides, drop them to about 1/2" open and try to "rock" them I'm sure there is a guide to valve spec somewhere. If they are too loose... the valve will not stay seated(sealed) for long

I use a brass wire wheel. A regular steel wire wheel can burnish the steel valve. A brass wire wheel you can grind all you want and not mess much up.

You should still spend the five bucks on some lapping compound and a valve grinding suction cup tool.

As with most projects like this, simply use a metal/abrasive that is softer than the substrate.

curtis73 wrote: I use a brass wire wheel. A regular steel wire wheel can burnish the steel valve. A brass wire wheel you can grind all you want and not mess much up. You should still spend the five bucks on some lapping compound and a valve grinding suction cup tool. As with most projects like this, simply use a metal/abrasive that is softer than the substrate.

Just be DAMNED SURE not to get any abrasive into the valvestem/guide area.