What percentage (cut with water I am assuming) and how long do you let it cook?

Iron is porous and the best way to remove oil/grease from it is to bake it(Best way)or heat it with a torch/heat gun if you're doing it at home.......You can take a block fresh from the machine shop and go over it with a torch/heat gun and it will sweat oil residue from the iron....which is what lifts the paint in the first place. We're not talking "Red Hot" here, just warm enough that if there's dirty iron it will smoke......about 10 minutes with a simple propane torch will tell the story. After that you have nice warm block ready for paint. Spray on cleaners work but they mostly clean the surface. Some shops have better equipment than others, but I always sweat the parts first to make sure....medium coat of paint to seal it off....assemble the engine...final coat of paint....Done.

1,1,1 Trichloroethylene is carcinogenic, 1,1,1 trichloroethane isn't. http://www.cdc.gov/niosh/npg/npgd0404.html

So you're wrong about that. It is listed as an ozone deplete, so I must ask if you have ever disconnected any emissions controls on your cars, because that causes air pollution which is much closer to home, the earth's surface.

This whole subject is moot, however, as the Montreal Convention banned its production starting in 1996.

R.

Well thats good to know. The chlorinated brake cleaners dissolve oil faster, but I try to avoid them usually because I always thought it was a carcinogen (confusing with trichlorethylene). I notice it does tend to leave a residue though, vs the non-chlorinated cleaners. It does do some funky things to latex gloves too.

Let's not forget what it does to your fingers! It sucks all the oils out of them and for me at least it burns like mad.

R.

After I re-read the original question I realized it's in a longblock form already... I usually use the muratic acid if it's a bare block and the hot tank did'nt get it like I wanted...I'm not sure I'd do it with an assembled longblock...I put the block on an engine stand,plug holes, and start pouring...Let it cook for a while{until it looks like it's not doing much more} and drain it....You would'nt believe what comes out of a "clean" block...Turn the engine to a different position and repeat...
I'll have to check on what strength{there's different concentrations} I have in the gallon containers.. I just used it straight last time...We have to do this to our fishing boat every few years to keep the sea water passages open it really cooks the debris out...

Makes my fingers tingle, and yes, sucks the oil out and gives you dead/pealing skin like when you're in the water too long!

Exactly!
The solvent suspends the contaminants and they must be removed in suspension or they just lay back down when the solvent evaporates.

I agree with the grease and wax remover. I've painted blocks in the past using brake clean, carb cleaner, lacquer thinner. It all evaporates to quickly. We always use single stage urethane. The only thing that seems to harm it is the dye from race gas can stain it. Everything else won't touch it. I'm not afraid to use bondo either, holds up perfect unless it's close to the exhaust, IE BB valve cover with stock manifolds. You'll notice my heads have no casting roughness or Indy logo. I have a bondoed factory cross ram that has the same finish as the engines in these pics that was bondoed and painted over 15 years ago.

For a dead on perfect job should a person use the cleaners then sweat the rest of the oils out with a torch then reclean OR torch then solvents? (OCD)

I really enjoyed this post. I'll tell you what I use. I hit greasy stuff with mineral spirits to loosen up the stuff in the cracks and crevasses. Then use compressed air to evaporate the residual. Then I hit the parts with POR Marine Clean (spray bottle) and a clean brush and rinse. This stuff will strip the [censored] off a sow and is fine for you and the environment. Just wear rubber gloves and a mask cause it will strip your skin oil and burn a bit in higher concentration. even 10:1 it's amazing.