VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Engine Cleaning

Has anyone ever tried to clean a block, while torn down, with a high-pressure water cleaner?

In the old days we would take the block to the machine shop and ask them to "boil it out in a Hot tank", which meant to insert the entire block into a tank of hot water with a lot of lye or a basic solution of NaOH (sodium hydroxide or calcium hydroxide) which is really like "Draino". The basic solution would eat the oil and carbon and leave the block whistle clean. But with the all the tree-huggers and folks worried about the pollution effects, most of these "hot tanks" are history.

I do not know if the new de-greasers do a good job? So I got to think'n (I know its dangerous) about doing it myself.

Mike

The last time I did an engine, I got it hot tanked. Depending on the vintage of the engine, you do have to be concerned with cleaning out all the oil galleries. As well, you need to clean crud from the water passages. Unfortunately, most do it yourself cleaners will either dissolve grease/oil real well or clean water based crud (like CLR), but not both. I guess you could do it in two passes, solvent for oils first and then something like CLR for the water passages. A kiddie pool under the engine stand would be good to collect the debris. then there is proper disposal. Wear a rubber suit! it is gonna be messy.

You can thank the "tree huggers" for your clean drinking water.

I had good success using a biodegradeable cleaner (Simple Green or that Purple stuff) and my pressure washer. It cured my overheating problem as I got lots of thick and chunky crud out of the head and block. Be sure to remove the freeze plugs (core plugs) for improved access into the deep recesses of the engine.
Yes, it's an ungodly mess and you should at a minimum wear eye protection and gloves. You never know when a high pressure stream of water is going to come back at you.
I wasn't so concerned about cleaning the oil passages as I was the cooling system. Modern detergent oils continue to do their job and clean the areas my pressure washer didn't reach.

I had a friend that owned a transmission shop with a hot tank cleaner and did a block for me, came out pretty darn good. Might check that out.

Mike,

I recently had my 216 torn down. I had the head off and the pistons out. During this process, I determined that my bearing clearances on rod and mains were good and the pistons were a good tight fit. Someone had replaced the block at sometime in the past. (I did go ahead and replace the rings while I had it apart.) I took the head to a machine shop for a complete rebuild. While they had it, I removed the freeze plugs. At that time, I stuck my finger into the block and found about 1" of rusty crud in the block. I took a piece of bent wire, almost 1/4" thick. I used this to scrape around all of the outsides of the cylinders and I also used it to push crud towards the freeze plug holes. I removed as much of the crud as possible this way. I then took my pressure washer and jammed the water nozzle down on top of the block and blasted through all of the water ports in the top of the block. I worked from the outside of the block toward the center, using the freeze plug near the center on the left side to let the crud flow out. I went back several times with my stiff wire and worked as well as I could on the interior of the water jacket. On the last flush of the block, I ran water until it ran clear.

After reassembly of the engine, I refilled it with clear water and ran it for about an hour. Long enough for it to get hot and let the t-stat open. I drained this water, which was rusty colored, but no chunks, and refilled with clear water again. I then drove the car for about an hour and drained the water again. It was still a little rusty colored, but not bad at all. I then refilled with a 50/50 solution of antifreeze. It was a messy process, but I was not going to remove the block and this seemed to be a reasonable method of cleaning out the decades of crud. All seems to be fine.

Rich

Hi Mike,

Your procedure is basically what is necessary when any engine is rebuilt. If you have facilities to hot tank the block that is recommended.

Assuming you did some maintenance on your radiator, you should not have any serious problems with your engine overheating.