You Never Wash Up After Yourself

I know, I know... I said it was "business time" and I didn't do anything. Well, I was busy. I went to Germany and was generally occupied with life. But tonight, I cleaned the engine block for test-fitting.

To do this, first I had to assemble the necessary cleaning elements:

Lacquer thinner, carb cleaner, WD-40, Chem-dip, engine oil, engine brush kit, a bucket and various rags.

Also I had to hook up my newest purchase, a siphon sprayer:

You see the block needs to be real clean before you put any parts on it. Like, no dirt, and try to get all the rust off too. Just a few specks of dirt in the wrong place, then when you wind the engine up to 6k and things get all hot, and you could really do some serious damage to all those moving parts. So, the engine needs to be real clean.

First you hit it with the lacquer thinner. Use a stiff bristle brush and really give it a once over. Then stick the the siphon part of the siphon sprayer in the lacquer thinner (the long blue hose is connected to the air compressor) and spray air/solvent into the nooks and crannies of the engine.

Once you do all that, it's time to get the engine brushes out and clean out all the passages for the oil and water that flow through a healthy engine.

Then it's time to brush the cylinder walls. You're supposed to put lacquer thinner on a rag and wipe down the cylinder, then use the biggest engine brush (you can see a bit of it in the picture above) and keep washing it down with solvent as you brush. Then check the cylinder with a white towel and make sure you don't see any residue left. Mine were pretty dirty/rusty:

After they are all clean, coat them with WD-40. Next use a really soapy solution of water and laundry detergent to once again clean out the block; then hit it with the siphon sprayer. This time blow soapy water though. Then use the small engine brushes to clean the fiddly parts (oil galleries etc.). Finally rinse the soap off, spray with WD-40 and run your fingers though the engine looking for any sign of dirt.

If you find any (I did the first time). Redo the soap wash steps and check again.

Finally my engine block was clean.

HOWEVER, I did find a crack in the block. I'm not sure if it's a big deal because it's in a bolt hole that is on the front right of the engine. Look at the following diagram, the bolt-hole in question would be the one on the bottom right of the picture.

Here are pictures of it:

So, car people: is this a deal breaker for the engine block? Do I need a new one, or can I proceed?
(Here's a song for you while you answer)