cleaning a block on the inside

Not sure about the current thread, but I am working on one right now. The first thing you have to do is physically clean out the water jackets. Most of the crud is around the rear cylinders. A lot of casting sand, wire, etc. Need to figure our what works to break it all loose, I use wire, screwdrivers, long drill bits, whatever will work! Keep rotating the block to dump the crud out and blow it out with air. You will be amazed what comes out.
 
I have heard that various lengths of frayed old speedometer cable chucked in a drill work well. (More flexible than drill bits, etc. Be carefull; they are probably more likely to bite back.)
 
I have used wire rope/ cable 1/4 in or 3/8 in about 12 in long, put one end in battery drill ,run in reverse to stop it unwinding and work it in and out in every cavity .
 
I made up a long drill bit out of welding rod by flattening the end and filing it to a sharpened point so I could drill into the hardened casting sand around the #8 cylinder and break it up. The rod is mild steel so it won't cut the cast iron. There must have been two cups of crud that came out of that area alone.

If you use compressed air to blow out a dry block be sure to do it outside. I didn't one time and the dense red cloud that filled my shop was something to behold. I wiped rust off everything for days.
 
I used most of the above methods and finished up with my 2500# pressure washer. I was amazed at the amount casting sand, etc that came out.
 
On scaled and rusted up block cooling systems, my uncle uses a small sand blaster. Using a small tip, he places it in a water hole, then turns the air on, that way he doesn't blast the block surface. With the block on an engine stand, its easy to turn it over and let the crud fall out.
 
I spent an entire day cleaning my 59A after it came from the tank. I put the block on my engine stand and wheeled it outside and used my pressure washer for hours, crap just kept coming out. I used improvised scrapers, picks, wire and a telescoping pen magnet( you will be amazed at what that would get out).
 
Acid stripping is the only way to get all the scale and rust out.

If you don't get it all out, you very well may have an engine that runs hot.
 
Acid cleaning would be great for rust, but will it do anything to remove the casting sand Pete? I'm asking because all I have ever done is the normal hot tank cleaning and it does nothing to remove the casting material. My current block has had a least one previous rebuild and after I took it apart and hot tank and water pressure cleaned it there was still an unbelievable amount of crud around the rear cylinders. Should have taken a photo of the pile of sand and other crud that came out of the thing!
 
JSeery said:
Acid cleaning would be great for rust, but will it do anything to remove the casting sand Pete? I'm asking because all I have ever done is the normal hot tank cleaning and it does nothing to remove the casting material. My current block has had a least one previous rebuild and after I took it apart and hot tank and water pressure cleaned it there was still an unbelievable amount of crud around the rear cylinders. Should have taken a photo of the pile of sand and other crud that came out of the thing!
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Yes, it removes sand. When you get the block back it is bare metal everywhere. There is no residue.

The acid used is a combination of several.
 
After chipping away heavy crud with long rods . use 3/16 " wire cable inside Chevy push rod that has both end cut off. Chuck in drill and go after it.
 
JSeery said:
That would be nice!!
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Like Pete wrote the acid cleaning is the best way and its not that hard. Here's how I do it.
After the block has been degreased I place it into a large container filled with citric acid powder and water mixture. Citric acid powder is easy to buy on Ebay cost is usually less than $30.00 for 15 pounds of powder.
I protect the machined surfaces such as the cam bearing holes valve seats and main bearing surfaces with a thin coating of grease. It takes no more than 24 hours to clean the block to the point where it looks like a fresh casting. The water mixture can be reused and since its safe for the environment it can safely disposed of. ;)
Ronnieroadster
 
First, bake and shake. Next, prod and probe with tools, cables, and air pressure.

As an aside, I sold a beautiful V-12 Lincoln engine block to a friend who used the acid treatment. ALL surfaces were either oversize or undersize when it was considered "clean" and de-rusted. A totally ruined rare piece. SO, be very careful no matter what you choose to do.
 
I cleaned the inside of the water jackets, using the various methods mentioned in posts here (I mostly used a long screwdriver and just kept digging away until nothing more came out), of the engine in my roadster (avatar). I actually shop-vacuumed it all out and measured what came out - an old gallon paint bucket was nearly full to overflowing with sand and debris. Probably one of the main reasons why these engines overheated. As you all know this car has been all over and it has never overheated or even got warm. The highest temp it's ever been was 190 on the Salt Flats. If you do anything to a flattie block, cleaning it out as described here is probably the single best thing to do IMHO.
 
Fellas , this has been one of the best discussions I have ever read on
Ford Barn , congrats ! Everyone in the past has talked about poor design of the flat head as the heating issue , but from this series of posts , it seems
one of the major issues was that the rear cylinder water jackets were never
well cleaned of sand casting from the factory ....and that 60-70 years later
it can be done .....mainly with mechanical methods . Thanks for the
great information , Mick
 
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